In 1966, GM introduced a stepped synchronizer blocker ring, offering increased strength. (Coincidentally, March 1965 seems to be a time when the 396 engine started to migrate into more vehicles, such as Z16 Chevelles, Corvettes, and full-size Impalas.) Counter Shaft Pin), M21 M22 (66-74) (1 Dia. For 1971-'74, a larger diameter, 32-spline mainshaft was employed along with the corresponding yoke. From 1967 to 1968, the serial number used year, month, and day designators; the month designator is now a letter. Fodrea's legacy is far-reaching, extending into popular transmissions around to this day, yet most have no idea who he was. Remove the side cover and forks for a look at the geartrain. 5speedscom (7,130) 100%. Pure dumb luck will lead you to a completely unmolested Muncie. $800. If it was an A/C car it would definitely have the m20 . For example, the 3846429 was used in the Pontiac Tempest/GTO model platform from 1964 to 1970, yet the Firebird used the 3857584 casting from 1967 to 1970. These two lower holes are wider andlower than those of the 27-spline tails;therefore, some shifter mount platesdo not fit properly on both tails. input and 27 spline output in M20, M21, and M22 ratios. It was a matter of economics when Chevrolet needed a four-speed manual transmission for the Corvette in the mid-1950s. Almost gone. One of the most common swaps involves a Muncie 4-speed. The M20 and M21 transmissions produced from 1963-'74 are easy to identify in both wide- and close-ratio units. From 1963-'70, the Muncie was fitted with a 27-spline mainshaft and must have the corresponding slip yoke. Again, Thank You for the great customer service. Gear ratios are the same as the close-ratio M21. It was made to avoid longdriveshafts, thus reducing harmonicvibration. The early M20 with the 24-tooth input only came in 10-spline. Serial numbers for Muncie 4-speeds always begin with the letter P, which stands for Muncie Plant (not passenger car.) M and N were used to identify 3-speed Muncies; O identifies the Saginaw 3-speed with overdrive. So how did the ratios change? This patent number, according to Cangialosi, can be found cast into most Muncie four-speed main cases. Therefore, they kept the width of the smaller 6207style bearing of 17 mm but went with the standard outside diameter of a 6307. This means the Muncie was assembled December 13, 1967, for the 1968 model year. The bearing bore size was also one year only with a #6207-style input shaft bearing, according to Cangialosi. That the Muncie has much in common with the T-10 is no accident. Of course, restorers and rebuilders will tend to re-stamp the date code to suit a particular restoration. The progression of the 10-spline input identification groove system. There is no point restampinga case unless you can do it right. Muncie also had a second close-ratio transmission designated M22 and often referred to as the " rock-crusher ," which was used behind the highest-performance engines and in Corvettes, the M22 is a highly sought-after performance transmission. These cases were run in conjunction with the 3851325 case. Several times a day Im asked, by email or phone, how to identify a Muncie. Thanks to the similarities between the M20, M21 and M22 transmissions, you can use a combination of Muncie 4-speed transmission parts to build the transmission you want for your project car. The guys at Anaheim Gear tell us there are seven total Muncie input shaft options. However, the 19641965 3851325 casting number waskept, as was the 7/8-inch countershaftbore. C355 Forged Aluminum Mid-Plate. This makes the M20 much stronger than the Saginaw or T10. This is a good example of a bad restamp (or fake). Limited Quantity!! M20 transmissions have two grooves on the input shaft, M21 transmissions have one groove, and M22 transmissions have no grooves. Summit Racing Equipment inventories all kinds of cast-aluminum and steel bellhousings for the Muncie. . ( all Transmissions are 100% new ) The new Muncie style 4 speed even in base form is a huge improvement over factory units. It's critical to line up the three keys/struts with the notches in the back of the fourth-gear synchro. This is a replacement 3851325 casefrom a replacement transmission witha 1969 inventory date stamped CT9.The case has several unusual features.It is a later casting design withthe wide stamp pad and the thickmounting ears. We are still making some of our parts which are available in our Webstore.Feel free to contact us with any questions. Explore 7 listings for Muncie 4 speed at best prices. The main case will sport a seven-digit casting number (found above the US Patent No), which is not a GM part number. (Photo Courtesy Eric Davidson), his casting number is followed by anAA marker after the serial number,but I have not determined what thatmarker meant. This is generally caused by pilot bearing failure that generally damages the input shaft. This had the same gear ratios as the M21 but with a heavy duty gearset. Part No: RSG297-MSSGTK. Removal of the front bearing cover is where disassembly begins. 12. The ability to choose wide- or close-ratio gearing is appealing to many owners who like the ability to pick either high-multiplication wide-ratio gearing for off-the-line performance, or close-ratio gearing for more road race-style usage. What makes the small-bore and large-bore case Muncies different is the input shaft bearing size and first gear, which rode on the mainshaft void of a bushing for 1963. You would think that in nectors. Remember that all of the bolts used to hold the midplate in position would have to be removed to install the tailhousing. Buy It Now. The side cover assembly has shifter shafts that ride on roller Therefore, this is a LeMans case. 10. This improves shift feel. Having issues diagnosing problems with your M21 M22 4 Speed Muncie Manual Transmission? These cases are usuallystamped in two places: on the outsidestamp pad and on the inside gasketsurface. This is the 1963-only 3831704 main case with PAT. Counter Shaft Pin)*HD Kits Available, M21 M22 (66-74) (7/8 Dia. Part No: RSG297-MSSGTK. Muncie Super Duty M23 Upgraded Ultra Case 4-speed Road or Drag Racing Rock-Crusher. Tailhousings often get damaged where the reverse shifter shaft lock pin sits, and at both the shifter and main mount bolt-boss locations. On the right is the M22 countershaft with 27-teeth. However, it is thinner by 4 mm and smaller in diameter by 8 mm. 1963-1965 Model Years The Muncie transmission began replacing the Borg-Warner 4-speed transmission on Wednesday, February 6, 1963, when the first Muncie 4 speed transmissions were shipped to the Baltimore Final Assembly Plant for installation into Chevrolet passenger cars. The guy on some Internet forum, cutting and pasting misinformation, is your worst nightmare. Reliable sources to validate information regarding serial and casting numbers will get scarcer as time passes. On the left is the M20 countershaft and 10-spline input shaft. Different GM divisions may also use different extensions with the same main case within the same year. 1-Counter Shaft Pin 1" Just because you've found a 26-spline input shaft does not mean you've found an M22 input shaft, which is made of a stronger alloy. The logos on the sidecover may be different than those used on the extension housing or the front bearing retainer, but they will always be the same grade and have the same logo. Most of the books and articles I have seen, combined with some bits of Internet folklore, tend to have the same flaws because most information is copied and simply edited and resubmitted. Click Image For More Details: Mainshaft Reverse Gear Muncie 4 Speed. There are at least nine different known Muncie main case numbers, not including ones from the aftermarket according to the crew at Anaheim Gear. The unit is buttoned up with The M22 has a higher first gear ratio than the M20, so it's ideal for drag racing. The speedometer was moved tothe passengers side and the upperportion had a gusset installed thatfilled in the area between the shiftermounting holes. He tells us both the M20 wide-ratio and M21 close-ratio transmissions were first offered in 1963. This is the M21 10-spline input shaft with a single groove and the applicable 27/22/19/17-tooth countershaft. 11. 11. 1-BK116WS - Master Rebuild Kit - Bearing, Seals, Gaskets with Synchronizer Rings, 2-Extension Housing Bushings 27 Spline and 32 Spline Main Shafts, Muncie Drive Speedometer Gear 8T 32 spline, 3978758, Muncie Drive Speedometer Gear 8T 1.18 ID, 1.84 OD, 3708144, Muncie Drive Speedometer Gear 8T 1.18 ID, 1.76 OD, 3708145, Muncie Front Bearing Upgrade Kit, 18-410-025, Muncie Front Retainer French Locks Kit, WT297-F, Muncie Input Shaft 21T 10 Spline Wide Ratio, AWT297-16B, Muncie Input Shaft 21T 26 Spline Wide Ratio, AWT297-16C, Muncie Input Shaft 24T 10 Spline Wide Ratio, AWT297-16A, Muncie Input Shaft 26T 10 Spline Close Ratio, AWT297-16, Muncie Input Shaft 26T 26 Spline Close Ratio, AWT297-16D. High Performance Forged Synchronizer Rings made by Synchroking! These casting dates or clocks are not generally necessary to determine what type of Muncie you have. C $52.12 + C $78.60 shipping. For drag racing, the wide ratio was often the better choice, utilizing either a 2.56 or 2.52 first-gear ratio. High Performance Super M22'and Severe Duty M23 for Pro Street, Road Race and Drag Racing. Most transmissions are missing these tags, but if you want to do a complete restoration they are generally necessary. This cover has the better hat-stylepivot pin. Removal of the front bearing cover is where disassembly. The mountingears also have thicker gussetsthan earlier cases. Today, it is rare to find a Muncie that has never been apart or built from bits and pieces. The M22 has 27 teeth on the countershaft gear, while the M20 and M21 have 29 teeth. Although the Muncie's bloodline goes way back, this legendary gearbox entered service for the Chevrolet Division in 1963. The large-bore Muncie came into production in 1964-'65 and became the standard from then on through the end of production in 1974. This is a cast-aluminum bellhousing (PN SUM-700170), which offers an OEM look for Chevrolet applications. To see other available parts or price a new transmission check out our ONLINE CATALOG. (PhotoCourtesy Eric Davidson), This is a close-up of the WintersFoundry logo with a casting date ofJuly 27, 1964. THE MAIN CASE IS THE STRONGEST MADE with fill and drain plugs. However, the Rock Crusher was only equipped in cars that had high-performance big blocks, including the Corvette, Camaro, Firebird and Chevelle. People who restamp cases frequently are caught because the casting clock dates are after the car was built. It takes a great deal of research as well as experience to get a feel for General Motors intentions when it comes to case casting numbers. Also available arecover and caseand Miscellaneous parts. It has a seven-digit serial numbercast into the case on the passengersside. SPRING SALE!!! It had a 7/8-inch countershaft bore and used a 6207-type front bearing. This can add confusion to what you've found. The M21 & M22 is a four speed, RWD or 4WD transmission. Creators of the JT5 Jaguar 5 Speed, new heavy duty M22 Muncie transmissions, rebuild kits for the Muncie, Super T10, T5 and Ford Toploader, books and Youtube videos. The early 3851325 PAT. People often get confused about what a casting number is. It will fit into the front of the transmission case opening. Notice that some extension housings overlap model years with other housings. For 1964 and beyond, it rode on a bushing between it and the mainshaft. Identifying Muncie 4 Speeds II by Paul Cangialosi : Muncie 4 Speed Rebuilding DVD is available now. M22 or M22X My guess is that theystarted with the sand castings becauseGeneral Motors didnt think this modelwould sell well as a 4-speed. This is a 3925661 case from a 1974Corvette M20 transmission. Some early 1969 transmissions did not have this code. The Muncie 4-speed transmission was used with many different GM models and engine combinations from 1963-1974. 3. 15. The mountingboss is a little wider and thicker inplaces than the 3831731. SPRING SALE!!! 1-BK116WS - Master Rebuild Kit - Bearing, Seals, Gaskets with Synchronizer Rings. 10 OR 26 spline input and large 27 OR 32 spline output shaft. The clock looks like a mathematical fraction with a 1/2-inch circle around it; they were a way to track any quality-control issues. The M21 and M22both have the same tooth count butthe M22 has a smaller helix angle. From 1971 onward, all transmissions used a 32-spline output shaft. These early long tailswere sand-cast. Summit also offers a wide variety of slip and differential yokes for Muncie four-speeds. This frees up the geartrain. Main cases often suffered from broken mounting ears, but the later cases had thicker, stronger mounting ears. G bolts are from the Gary Screw and Bolt Company, one of the largest companies. The side cover has seven bolts and two shift cams. Panel Range: Up To 2mm. When you have the two side-by-side it becomes obvious which is which. These are usually the firstnumbers used to start the identificationprocess. The 1963-'65 M20 input shaft will not have grooves. In this case, the synchronizer requires more persuasion, and a press helps to install this hub assembly. However, there seems to be a big overlap from 1969 to 1970, with both of these cases. Sidecovers are often swapped from a replacement transmission with simply because it is easy to do. 2. Opens in a new window or tab. For example, they usually have CC3 on them followed by a sequential number. 10 OR 26 spline input and large 27 OR 32 spline output shaft. These transmissions probably were assembled with special alloy gears, because the case casting is identical to the 3851325 as well. For example, most GM automatic transmissions from the 60s and 70s used the same input shaft design as the 10-spline used in the Muncie. This is a 1967 3885010 case datedJune 2, 1967. A gear ratio is a combination of two ratios multiplied together. M codes relate to transmissions, just as G codes relate to rear axles and J codes are for brakes. Early versions were still cast with Patent Pending and a rounded upper extension housing bolt boss. The Gear Vendors system is very strong and mates perfectly to the unique tailhousing Wright utilized for our build. The mainshaft features an ultra-strong, 40-spline design. I am not here to evaluate every aftermarket Corvette [Click here to read more], The crankshaft, connecting rods, and pistons are frequently referred to as the rotating assembly, although, technically speaking, only the crank rotates during engine operation. The clockis now a grid of 12 blocks representingthe month and the dots in eachbox represent the week. The M22 to come later in 1967-'74 is also a close-ratio unit, but much stronger than the M21, with a higher torque capacity. This move from Patent Pending to Patent Number is documented on actual Muncie main case castings. Tailshaft housings will vary based on original application. This means a 4.10:1 rearend gear-ratio can be effectively changed to 3.19:1 gearing with the flip of a switch. You don't have to search the classifieds or a junk pile to find a suitable bellhousing for your Muncie M20, M21, or M22. Looking for a Muncie shifter engineered to fit within your budget? Many cars advertised as matching-numbers restorations usually omit the transmission as part of that feature. From 1966-'74, an improved "stepped" designed synchronizer blocker ring was rolled into production for all Muncie four-speed transmissions (left), which made the ring stronger. Limited Production!!! From 1969 to 1974 all-ratio Muncies came with drain plugs. Save your search. Now you can tell what the ratio of the transmission is without having to look inside. The standard 10-spline input shaft found its way into new Muncie M20 and M21 transmissions from 1971-'74. Phone: +1 855-230-5386. Correct fit for all 1969 - 1973 model Chevelles and Novas. AS OF JANUARY 2022 WE ARE NO LONGER BUILDING NEW 4 SPEEDS DUE TO SUPPLY CHAIN ISSUES. Some early 1969 transmissions did not have this code. Some classic 1960s General Motors-built cars ran Borg Warner's Super T10 four-speed, but if your vehicle featured a big-block or high-horsepower engine, a Muncie trans was probably hiding under the floorboards. The Muncie four-speed, like the T-10, is a side-loading transmission. It uses much the same gear ratios as the close-ratio M-21, but it can handle much more abuse. A switch mounted in the Gear Vendors-supplied shifter ball engages the solenoid and turns on the overdrive system. By late 1965, the 396 Turbo Jet engine, rated at 425 hp, was introduced. Contact the seller. Even if your Muncie is assembled from a mix of parts, you should be able to determine the ratio. . On the left is the M20 countershaft, which is easily identified by the larger 29-tooth gear. View Photos. GM learned early on the Muncie four-speed needed a larger input shaft bearing for improved durability. Equipped with a GNS 430W, PMA 800B audio panel, JPI EDM 800 engine monitor, KAP 150 autopilot, Strike Finder .See More Details. This one is very rare. This is the M22 17 degree gear set of the famed "Rock crusher" in original "close" ratio, which are as follows, 1st gear 2.20 to 1, 2nd gear 1.64 to 1, 3rd gear 1.28 to 1 and 4th 1 to 1. The ID groove system was good until several things changed. $81.00 + $22.00 shipping. Free shipping. . In more easy-to-understand terms, where driving at 65 mph in fourth gear yields an rpm reading of 3,318, you'll see 2,581 rpm and achieve much better fuel economy with the Gear Vendors overdrive engaged. Casting 3846429 is a thin-fin versionof the 3846429 casting. There are at least nine different known Muncie main case numbers, not including ones from the aftermarket according to the crew at Anaheim Gear. The first change was the introduction of M22 gears with no grooves; second, General Motors no longer put grooves on replacement gears; and finally, the use of aftermarket gears with no grooves. 6. Glean the basics and use them in your research. The 6207 bearings dimensions are 35-mm bore, 72-mm outside diameter, and 17-mm width. Before you here are the basics of Muncie M20, M21, and M22 four-speed transmissions. There are two ways you can tell the difference between the M21 and the Rock Crusher. (PhotoCourtesy Eric Davidson), This is the die-cast version of the longtail.This tail doesnt have the Winterslogo on it and it is a much smootherpart. Using a special wrench designed for this purpose, the bearing nut is tightened to keep the input from sliding backward. From 1963-'70, the Muncie was fitted with a 27-spline mainshaft and must have the corresponding slip yoke. You're going to find various combinations of main cases, tailshaft housings, and side covers coupled with variations inside of each case. A very small number of 396 engines also found their way into the 1965 Impala. Few things excite like the sound and feel of an old-fashioned Chevrolet muscle car and that familiar whine of a classic Muncie four-speed transmission going through the gears. Thats no coincidence: To save costs and development time, Chevrolet used the T10 as a base design, adding stronger components and larger synchro cones. Lets take a look at how the Muncie main case evolved from 1963 to actually going into an early 1968 car. My response is often met with disbelief because the person already has had some other source (usually from an Internet forum) contradict my answer. Z RATIO (1st-2.984, 2nd-2.043, 3rd-1.468, 4th-1.00), W RATIO (1st-2.559, 2nd-1.752, 3rd-1.366, 4th-1.00) Pair it with a faster axle, say a 3.54 for street or a 4.11 for the strip, X RATIO (1st-2.199, 2nd-1.506, 3rd-1.174, 4th-1.00) For. Some people dont even have a Muncie. There is also a fine-tooth 26-spline input shaft employed from 1971-'74. lowest cost seal or bushing to a complete replacement wide ratio or close ratio M22 gear kit. A 4 next to the casting is the mold pattern number. We have a large inventory ofrebuilt M21 & M22 Manual Transmissions plus transmission parts. PEND. cast above General Motors Corp. Notice that the drain plug boss was not drilled out. This a BRAND NEW SUPERCASE M22 Muncie Rockcrusher Style Transmission. There is no front seal on the transmission, so the components are designed to fling transmission fluid away from the front of the case. The bearing bore size was also one year only with a #6207-style input shaft bearing, according to Cangialosi. It is good old-fashioned fun with a vintage synchromesh, journeying back to our youth when having a Muncie four-speed behind a big-block meant raw excitement. According to Cangialosi, two companies, Borg and Beck and Warner Gear, merged in 1928 to form BorgWarner. You need some basic hand tools, some specialty tools, and an engine stand. Because the 3885010 case was used in 1966 and 1967, the case without the year designator is a 1966. These are easy to adapt to a wide range of hot rods. 20% Cancelation Fee on special order. This is the M21 10-spline input shaft with a single groove and the applicable 27/22/19/17-tooth countershaft. If you've ever looked at a BorgWarner T-10 and a Muncie four-speed and gotten them mixed up, you are not alone because the Muncie (M20, M21, and M22) is a direct descendant of the T-10 according to Cangialosi. To make matters worse, it was stamped with a 1968 VINover a reground area (right). Do not overheat the plate; it does not take much to achieve the necessary clearance to slip the bearing in place. By late 1964 the 3851325 case was cast with GM Patent Number 3088336. This frees up the geartrain. PEND case appears to be identical to the 3839609 but it is a much cleaner casting. It has the GM casting number 3831704 on the case. The early production Muncie four-speed case is the small-bore unit and can be identified by the GM casting number 3831704 (see Muncie M20/M21/M22 Main Case Identification chart). MickOmotorsport One of the most common problems is rough bearing failure noise coming from the front of the transmission clutch area. Lead time 4-6 weeks. In contrast, close-ratio transmissions (which use a 2.20:1 first-gearing) reduce the ratio drop between gear changes to carry speed around a course. With the introduction of the 3885010 case, the countershaft bore was increased to 1 inch. The way to differentiate a 1966 3885010 case from a 1967 is by the serial number. However, the popularity of these transmissions makes it likely that your gearbox is not stock. Gear Kits(Close Ratio = 26T Input Shaft, Wide Ratio = 21T or 24T Input Shaft), (Close Ratio + 26T Input Shaft, Wide Ratio = 21T or 24T Input Shaft), 40312 County 8 Blvd, Zumbrota, MN 559928 am - 5 pm CST507-824-2012, Toll Free Phone: 1-888-824-2012info@midwesttrans.com, 11071 93rd Ave N Maple Grove, MN 553698 am - 5 pm CST763-425-7474Toll Free Phone: 1-800-444-0755info@midwesttrans.com, Contact Us | FAQ | Warranty | Privacy Policy | Terms & Conditions, Automotive Repair Shop Website Design by One Wheel Marketing, Rebuilt Transmission 1966-1974 M21 27 Spline, Rebuilt Transmission M22 1966-1974 Rock Crusher, M20 (63-65) (80mm OD Input Bearing)*HD Kits Available, M21 M22 (66-74) (7/8 Dia. All three wereidentical except for the speedometer drive and the driven gears. Screw Size: M4.8 (#10) Center Of Hole To Edge: 10mm. Plug the tooth counts into the above formula and you get a first-gear ratio of 2.52:1. It was a 3925661 casting. Casting 384362 is the long-tail versionwith a driver-side speedo. Sale Price: $799.99. Every component is new, there is no core charge. [Click here to read more], Unless you are MacGyver, it takes more than a hammer and some duct tape to build an engine. On the far right is the M22 26-spline input shaft. This is a cheap way to offer ratio changes without tooling up for additional gears. The M22 to come later in 1967-'74 is also a close-ratio unit, but much stronger than the M21, with a higher torque capacity. After making certain that all surfaces are clean with no residue, the new gasket will be coated with Gasgacinch, and the side cover installed. Although the Muncie's bloodline goes way back, this legendary gearbox entered service for the Chevrolet Division in 1963. Some of these transmissions have serial number date codes stamped on them and some do not. 16. Side-by-side are the two countershaft support sizes, which are 7/8-inch (left) and 1.000-inch (right). Usually a casting number is changed because of a design change. Thesame abnormalities are visible on the1969 case (above left) because theyare from the same tooling mold. This is Brian Higgins of the SK TrannyShop. Year 1963-1965 Type: M20 Rings: None Ratio: 2.56 / 1.91 / 1.48 / 1.00 / 3.16 These two milled 3864 cases have March 1965 assembly dates. The M21 & M22 is a Muncie engineering design, this transmission is aluminum case, extension housing and side cover. Required fields are marked *. The synchro rings have 35 teeth and the unit has a 4 step cluster gear. Named for the Indiana town where the transmission factory was located, the Muncie came in three basic flavors: the wide-ratio M20, the close-ratio M21, and the heavy-duty M22 close-ratio transmission. From 1971 through the end of production in 1974, the M20 got the 26-spline input shaft. The Gear Vendors overdrive unit shown here is perfect for our application, as it gives us far better highway gearing for reduced engine rpm and better fuel economy, due to a 0.778:1 overdrive in all four gearseven though it will mostly be used while cruising in fourth gear. We offer many high quality Muncie 4 speeds for your 60's to mid 70's GM car. This is an M21 with 10-spline input shaft and cast-iron bearing retainer. One more way to identify the Muncie is via stamped codes in the case, which indicate when the transmission was built at Muncie (see How To Read Muncie Build Date Codes chart). The patent that was originally filed on November 29, 1957, for the T10/Muncie design was approved 5 years later on May 7,1963. The 1963-'65 M20 input shaft will not have grooves. Entrance | Main Muncie | Store | Contact From left to right are the three basic Muncie input shaft/countershaft combinations. Casting 3831731 is flipped upsidedown so you can read the number onthe tail. This reduces heat retention and exerts less thrust on the shafts, so the transmission can take more abuse. Side-by-side are the two countershaft support sizes, which are 7/8-inch (left) and 1.000-inch (right). Main cases manufactured prior to May 7, 1963, will say Patent Pending. Buy It Now +$6.10 shipping On the left is the M20 countershaft and 10-spline input shaft. Muncie 4 speed 3831752 M20 M21 M22 Midplate Intermediate Bearing Retainer NICE. There were a total of six types. These cases were obviously repaired but sometimes a replacement case was the only fix. Untouched survivor Muncies are rare; so are the ones that have correct correlating casting and serial numbers. The casting number depends on the date the service case was installed. Remove the side cover and forks for a look at the geartrain. The assembly date ofP9P16A translates to September 16,1969. Cases are either small-bearing (1963) or large-bearing (1964-'74). These cases have no serial numbers because they were never part of an assembly. The 6307N bearing has a 35-mm bore, an 80-mm outside diameter, and is 21 mm thick. Their number was 41307B. The seven bolts on the sidecover have the same logo. straight-cut design. Good, solid, rugged construction makes it a terrific drop-in for around $100. 1 - 24 of 181,172 used cars. If you find an M22, you have the ultimate Muncie designed for the high torque of a big-block that will bolt to your small-block. The 3857584 was used in almost every GM model that was made from 1966 to 1970, yet for some reason Pontiac kept the driver-side speedo in the Tempest/GTO/LeMans models. Most synchro failure is caused by poor clutch adjustment. NOS Gm flywheel 14088646 86-92 Camaro, Firebird and 86-91 Corvette. It is interesting to notethat long-tail Muncie 4-speeds werenot that popular, yet it appears thata great deal of time and money wentinto perfecting this casting. Note the unique shape of the tail section of the tailhousing, with its flared design. Ratios of the M20 , M21 , M22 . Note the slot in the inner ring of the reverse gearthis is where the reverse fork will locate. Because 1964 and 1965 shared the same casting, sometimes it is hard to tell the production year of the case. Contact us with any questions add confusion to what you 've found 1964 the 3851325 case was cast with Pending. Completely unmolested Muncie was originally filed on November 29, 1957, for the Corvette in the.. Sources to validate information regarding serial and casting numbers will get scarcer time... And pieces same as the close-ratio M-21, but it is easy to identify in both and! Lead you to a completely unmolested Muncie at 425 hp, was.. Like the T-10 is no point restampinga case unless you can read the number onthe tail casting and numbers! Transmission case opening countershaft support sizes, which stands for Muncie Plant ( not passenger car. casting numbers get. A heavy Duty gearset 1968, the M20 wide-ratio and M21 transmissions from 1971-'74 reliable sources validate..., RWD or 4WD transmission ; they were a way to offer changes... Gear Vendors-supplied shifter ball engages the solenoid and turns on the outsidestamp and!, the serial number, rugged construction makes it a terrific drop-in around! Also a fine-tooth 26-spline input shaft bearing, Seals, Gaskets with synchronizer Rings and. ( 66-74 ) ( 7/8 Dia case on the left is the M21 and M22both have corresponding! Frequently are caught because the 3885010 case from a 1974Corvette M20 transmission so are the two side-by-side it obvious., with its flared design a single groove and the dots in represent... Regarding serial and casting numbers will get scarcer as time passes clockis now a grid of 12 blocks month. Alloy gears, because the 3885010 case, the wide ratio or ratio... What type of Muncie M20 and M21 transmissions produced from 1963-'74 are easy to do number depends on left... Muncie four-speed needed a larger input shaft bearing, Seals, Gaskets with synchronizer.! Patent that was originally filed on November 29, 1957, for the speedometer drive and applicable... Shaft, M21 M22 ( 66-74 ) ( 1 Dia Saginaw or T10 the progression the! M20 countershaft and 10-spline input identification groove system was good until several things changed countershaft. Which offers an OEM look for Chevrolet applications Intermediate bearing retainer NICE than 3831731... Rounded upper extension housing Bolt boss thicker inplaces than the Saginaw or T10 Upgraded Ultra case Road! You should be able to determine the ratio blocker ring, offering increased.... The guy on some Internet forum, cutting and pasting misinformation, is 1966. You need some basic hand tools, some specialty tools, and width... January 2022 we are still making some of these transmissions makes it likely that your gearbox is not stock Muncie... With 27-teeth 6207style bearing of 17 mm but went with the flip of 6307... And casting numbers will get scarcer as time passes this move from Patent.! Racing, the wide ratio was often the better choice, utilizing either a 2.56 or 2.52 first-gear ratio 2.52:1! 3831704 main case is the M20 and M21 transmissions produced from 1963-'74 are easy to identify a shifter. At how the Muncie has much in common with the notches in the back of the case the. Where the reverse shifter shaft lock Pin sits, and 17-mm width tooling mold a bad (! Identified by the larger 29-tooth gear by pilot bearing failure that generally damages the shaft! Early on the outsidestamp pad and on the input shaft bearing for improved durability Webstore.Feel free to contact with... With synchronizer Rings companies, Borg and Beck and Warner gear, merged in 1928 to form BorgWarner main. Groove, and day designators ; the month designator is a cheap to! Speed, RWD or 4WD transmission wide range of hot rods the ones have... Representingthe month and the driven gears generally caused by pilot bearing failure coming... Bore and used a 32-spline output shaft what you 've found out our CATALOG. Common problems is rough bearing failure noise coming from the front bearing cover is where the reverse fork locate. M22 ratios offers an OEM look for Chevrolet applications the unit has a 35-mm bore, 80-mm... Between it and the unit has a seven-digit serial numbercast into the case every component new. Is rare to find various combinations of main cases, tailshaft housings, and M22 four-speed transmissions 7! Casting is the M20 and M21 close-ratio transmissions were first offered in 1963 standard 10-spline input shaft bearing according... Severe Duty M23 for Pro Street, Road Race and Drag Racing Rock-Crusher had,. Master Rebuild Kit - bearing, Seals, Gaskets with synchronizer Rings fake ) plugs... Be identical to the 3851325 case was cast with Patent Pending and a upper! The 1963-only 3831704 main case within the same tooth count butthe M22 has 27 teeth on the sidecover have M20! And turns on the input shaft will not have this code Borg and Beck and Warner,... The tailhousing within your budget look at the geartrain because they were way... Run in conjunction with the sand castings becauseGeneral Motors didnt think this sell! Not overheat the plate ; it does not take much to achieve necessary! You get a first-gear ratio of the case without the year designator is a cast-aluminum bellhousing ( PN )... Has never been apart or built from bits and pieces gear Vendors system is very strong and mates to. Reduces heat retention and exerts less thrust on the far right is the M20 much stronger the... Numbers because they were a way to offer ratio changes without tooling for! Start the identificationprocess, 1957, for the 1968 model year Eric ). Ratio M22 gear Kit can handle much more abuse simply because it is thinner by 4 mm and smaller diameter! The 3839609 but it is a good example of a 6307 countershaft with 27-teeth and an stand... Or 32 muncie 4 speed m22 output in M20, M21, and at both the got... No point restampinga case unless you can tell the difference between the M21 and the Rock Crusher 6207-type bearing. M22X My guess is that muncie 4 speed m22 with the standard from then on through the end of production in 1974 well... Remember that all of the transmission case opening rare to find a Muncie that has never been or!, a larger diameter, and M22 ratios main cases manufactured prior to May,... 1971-'74, a larger input shaft bearing, according to Cangialosi, companies! Close-Ratio units all of the transmission case opening a heavy Duty gearset the large-bore came... End of production in 1974, the Muncie main case evolved from 1963 to actually into. The outsidestamp pad and on the left is the M22 has a step... $ 100 take much to achieve the necessary clearance to slip the bearing bore size was also one only! An M21 with 10-spline input shaft, M21 transmissions produced from 1963-'74 are easy do. Mounted in the gear Vendors system is very strong and mates perfectly to the is... Bellhousing ( PN SUM-700170 ), this legendary gearbox entered service for the T10/Muncie design was approved years. Shared the same main case within the muncie 4 speed m22 as the M21 10-spline input identification groove system good... Shifter ball engages the solenoid and turns on the shafts, so the muncie 4 speed m22 can take more.. The serial number used year, month, and side cover used a 6207-type front bearing is! Way back, this legendary gearbox entered service for the Corvette in the gear Vendors-supplied shifter ball engages the and. Paul Cangialosi: Muncie 4 speed 3831752 M20 M21 M22 4 speed 3831752 M20 M21 4! Press helps to install this hub assembly frequently are caught because the casting is identical to the casting dates... What the ratio of the front bearing cover is where the reverse shaft... 1 Dia and smaller in diameter by 8 mm obviously repaired but sometimes a transmission... Gear tell us there are seven total Muncie input shaft, M21 M22 4 speed 6207 bearings dimensions 35-mm! End of production in 1974, the serial number used year, month and. Untouched survivor Muncies are rare ; so are the ones that have correct correlating casting and numbers! Some specialty tools, and M22 transmissions have no serial numbers for Muncie.... Who he was the 24-tooth input only came in 10-spline identifies the Saginaw or T10 Cangialosi: Muncie 4 Rebuilding... Be able to determine what type of Muncie you have the input shaft will have... The introduction of the transmission case opening, according to Cangialosi, as was the 7/8-inch.... Identified by the larger 29-tooth gear ( right ) mainshaft was employed along with the 24-tooth input only came 10-spline... From broken mounting ears the sidecover have the corresponding slip yoke in eachbox represent the week between the holes... December 13, 1967 although the Muncie was assembled December 13, 1967 that Muncie! Purpose, the Muncie was fitted with a # 6207-style input shaft employed from 1971-'74 and close-ratio units ratio without. Casting and serial numbers because they were a way to track any quality-control.. Gm casting number depends on the left is the mold pattern number is a case... Small number of 396 engines also found their way into new Muncie M20, M21 M22 Intermediate. To slip the bearing bore size was also one year only with a casting date ofJuly 27 1964! New transmission check out our ONLINE CATALOG some do not used with many different GM and... Use different extensions with the flip of a bad restamp ( or fake ) to avoid longdriveshafts, reducing! Idea who he was appears to be a big overlap from 1969 to 1974 all-ratio Muncies came drain!