How to tell a muncie transmission m22 from m20. The second contributing factor has to do with getting .
- How to tell a muncie transmission m22 from m20. You can identify several unique signs that identify an Sep 6, 2014 · The Muncie M20 is basically a wide-ratio transmission and was intended for normal street driving use. Just need to button up the shifter, brake cable and carpeting and I can go for a spin to see if I got the right gear in there. Many owners want Nov 30, 2021 · He tells us both the M20 wide-ratio and M21 close-ratio transmissions were first offered in 1963 What you will find in your search for the right Muncie four-speed is conflicting information from different sources. 31 in my '67 ), while the M21 came in higher (numerical ) rear axle ratios. Sep 2, 2004 · An M22 gearbox has a 20 degree helix angle on the gearset as opposed to a 45 degree angle. 03:1 B 2. The Muncie 4-speeds (M20, M21, and M22) are some of the most popular manual transmissions ever made and continue to be incredibly popular. 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 cars. Home Reading Serial & VIN Numbers Muncie 4 speed serial numbers begin with the letter “P”. Fodrea. 20 ratio is commonly designated as the M21 transmission, while the 2. The center gear is from a BorgWarner T85 3-speed. If you are not sure how to distinguish between an M20, M21, or M22 Muncie, knowing what to look for can be tricky. From viewing threads on this forum, the two most popular options appear to be standard GL4 80W90 or Amsoil synthetic. Muncie 4-speeds were produced in two different ratios wide-ratio (M-20) and close-ratio (M-21). Identify a transmission type correctly before fitting it into your car. Aug 3, 2018 · The M20 and M21 transmissions produced from 1963-'74 are easy to identify in both wide- and close-ratio units. The first models had a 2. that will give you the ratio of first gear. No better sound than a Muncie clunking into place in the bellhousing. These M22 Nov 11, 2003 · I bought a '69 Nova with a 396 and a Muncie "M22" that turned out to really be an M20 in need of a rebuild :rolleyes:. The 2. Muncie also had a second close-ratio transmission called an M22, which Apr 1, 2008 · So, in this example, a car with 3. Here are some key factors to help you distinguish bet… Apr 29, 2017 · G. Just three types of Muncie 4-speeds are available based on the RPO (regular production option) code used when a car was ordered: the M20 (standard wide-ratio), M21 (close-ratio), and M22 (heavy-duty close-ratio). Muncie Disassembly Mar 29, 2016 · The trans and driveshaft are back in. The Muncie 4 speed was used in production vehicles until power levels dropped in 1975. Oct 17, 2008 · The most well known Muncie transmissions are the M20(wide ratio), M21(close ratio), and the M22(rock crusher). The "wide" ratio difference is that 3rd-4th drop that you noticed Yes, the 2. (Technically, there is a bit more RPM drop with each gear with an M20, but the difference is negligible. These new requirements led to the demise of the Muncie and the reintroduction of the improved T10 called the Super T10. Jan 25, 2022 · According to Paul Cangialosi, Muncie transmission historian, technician, and author of Muncie 4-Speed Transmissions: How to rebuild and modify, the Muncie four-speed transmission has its roots back to 1935 and the U. Mar 21, 2010 · Effective October 21, 1968, an additional letter was added to the plant prefix number to help identify the gear ratios in Muncie transmissions. Sep 23, 2018 · These 5 casting numbers identify all aluminum Muncie main cases: 3831704 – 1963 only 3851325- 1964-65 3885010- 1965-67 3925660- 1968-70 3925661- 1971-74 The 2. The additional letter codes as follows: Muncie 3 speed Manual Muncie 4 speed manual transmissions Suffix 1st gear ratio A 3. It was installed in the Camaro, Chevelle, Buick GS, Pontiac GTO, Olds Cutlass, and many other classic cars. Although not mentioned much, there was also an M23 transmission that was used, beginning in 1970. Oct 12, 2010 · So you can tell the difference by counting the teeth on the input or the cluster gear that engages the input. From 1963-’70, the Muncie was fitted with a 27-spline mainshaft and must have the corresponding slip yoke. Aug 26, 2020 · Bought a supposedly rebuilt M21 off of Craigslist for $500 from a sketchy guyof course no paperwork to prove the rebuild, so you know it hasn't been done. 52:1 first gear. An M-22 "Rock Crusher" is a Muncie four-speed transmission for cars made by General Motors in the 1960s. P0101 would indicate January 1st. Thanks for all the links. Vince Oct 7, 2014 · The Muncie four-speed is as legendary as the cars that it was put into, with the M20, M21, and Rock Crusher M22 models all part of the hot rod vernacular. The Muncie was the top high-performance manual transmission General Motors offered in its muscle cars of the 1960s and early 1970s. The Muncie M20 was a wide-ratio transmission and was intended for basic street drive-ability and basically for cruising your car . 20 1st. 20:1 first gear ratio while the M20 has a 2. The muncie can and will leak out the front bearing retainer under certain conditions causing oil to get on your clutch. It's been fine on the street, even with 28x11. Note how the Muncie gear is physically longer than the T10. The ratios are not the same in the M21 and M20. 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. The Muncie M20 is an updated version of BorgWarner’s T10 four-speed manual transmission, and it shares design similarities with the Saginaw four-speeds of the era. Lbs of torque, and they are close ratio, and is the latest factory ititeration of the beloved box. 20:1 ratio first gear is usually referred to as the Muncie M21 transmission; based on GM’s production codes. 56 ratio is commonly referred to as an M20. Otherwise you can tell a difference by spinning the input while in first gear, and counting the revolutions of the input with respect to the output. The Muncie 4 Speed came in 3 basic models… the M-20, M-21 & M-22. Before you here are the basics of Muncie M20, M21, and M22 four-speed transmissions. Aug 25, 2022 · Muncie M20- The Muncie M20 is a wide-ratio transmission with a gear set having a 2. If you have the incorrect transmission, your car may not function properly. The Muncie four-speed transmission was used with many different Nov 4, 2022 · 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. RPO M20 is wide-ratio 4spd; M21 is close-ratio 4spd; M22 was a specialty Heavy Duty close-ratio 4spd (I personally do not know if RPO M22 was used to designate anything other than the Muncie 2. Colvin discovered a Chevrolet Engineering Change Recommendation was issued in December 19, 1964, requiring a change of the M20/M21-style transmission to the M22 because of the Grand Sport Corvette Race Program. M20 will have 24 teeth or less on some models M21 has 26 teeth on about a 45 deg angle Jul 5, 2016 · A:Zack, I am excited that you and your father are working on a project car together. From 1963 to 1965 the close ratio M21 was ordered under the M20 RPO code and the factory decided whether to install a wide ratio M20 or close ratio M21 depending on the rear axle ratio specified. Jun 13, 2017 · The Muncie four-speed transmission was heralded by many as an “indestructible” four speed used by General Motors, and found its way into many different car models, behind various engine combinations between 1963 and 1974. The M22 typically has a 2. Oct 5, 2011 · The 'M-series' codes (M20, M21 and M22) are GM 'RPO' codes, like Z28 and WS6right down to the seatbelt retainers. That’s the type of transmission I used for this build. They are compatible with a GM 3 Series differential. The M22 to come later in 1967-'74 is also a close-ratio unit, but much stronger than Ratios of the M20, M21, M22. Dec 20, 2020 · Identifying the differences between Muncie transmissions, specifically the M20 and M22 models, can be crucial when restoring or upgrading a classic Chevrolet vehicle. The M21 & M22 is a Muncie engineering design, this transmission is aluminum case, extension housing and side cover. The serial number is a date code. M20 input = 21 teeth. Oct 28, 2015 · when looking at the "stock" GM ratios, all three versions (M20/M21/M22) have about the same ratio change/same rpm drop between 1-2 and 2-3. Get in the right gear with these tips Aug 7, 2018 · 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). This patent number, according to Cangialosi, can be found Nov 29, 2001 · Since Muncie parts can be interchanged during a rebuild the numbers may not tell you which trans it is. It is the heavy-duty version of the 2. Oct 28, 2004 · Also the input shaft cannot be used as a guide because there are various firms now manufacturing replacement input shafts that have no identifying rings. Took it to my transmission guy to check it out and, yep, no rebuild. M20: Wide ratio, mainly used in regular driving. I know that the M20 came in cars with a standard rear axle ration ( 3. 52 or 2. 11 or so. The straighter angle was designed to produce less end loading of the gear train and less heat but created more noise, thus the nickname "rockcrusher". For example P7C05 will read: Muncie four speed aluminum for passenger car 1976, March, 5th. 56 gears. Year Mar 17, 2021 · The M21 & M22 is a four speed, RWD or 4WD transmission. engineers decided to use the heavy gear oil for two main reason. The synchro rings have 35 teeth and the unit has a 4 step cluster gear. Jun 29, 2009 · The M20 is a wide ratio and was the standard GM 4 speed of the time. Jun 16, 2005 · It was replaced by the Muncie in late 1963. patent number 3,088,336 along with an engineer named James W. The Muncie four-speed transmission was used with many different Transmissions are an essential part of hot rod builds. Muncie takes its name from its home headquarters in Indiana. A new Muncie gearbox would provide a solid foundation for high-performance and racing applications. 91:1 ratio fourth gear suitable for street cars. Muncie 4-speeds were produced in two different ratios wide ratio (M-20) and close-ratio (M-21). S. Also M22 gear sets were of a higher nickel alloy. Oct 25, 2020 · Identifying the differences between Muncie transmissions, specifically the M20 and M22 models, can be crucial when restoring or upgrading a classic Chevrolet vehicle. Both reasons equally important. This difference can significantly impact acceleration. I was just wondering what the differences were. Sep 23, 2018 · The 2. I am not road racing or drag racing, just having some some fun on back Ratios of the M20, M21, M22. 11 rear gear. Dec 5, 2020 · Looking for some advice on which is the best oil to use in an original Muncie transmission. The M20 is the "wide ratio" version which begins with a 2. Most people I have spoken with have 500+ HP and think the M20 crack and basically destroy themselves. All of these factors led to a creation of a new […] Feb 10, 2008 · the 4+3 is a super T-10 with an overdrive on the back. M21 (close ratio) and M22(close ratio heavy duty) were options M21 and M22 have the same ratios but the M22 has straighter cut gears to help prevent end loading thats the only difference between the M22 and M21. and if you find one, I'll give ya $300 for a working overdrive unit, '87 and later. In this situation, I am speaking about an original M22 but I suspect the advice will be applicable to an M20 or M21 as well. Considering the age of the youngest Muncie, it is best to scrap the gearset if gears are broken or worn, fix all the case castings, and give the transmission all-new internals. This is what makes the car hobby so great. the 2. There are three basic types of Muncies: M20, M21 and M22. Jul 29, 2016 · Learn how to identify production code numbers, VIN numbers, and more on a Muncie transmission. These are easy to adapt to a wide range of hot rods. It's easily one of the most popular manual transmissions on the market. The reason for these design changes was simply to meet the demand for increased torque capacity Jan 8, 2006 · Yes, the Amsoil syncromesh is a direct replacement for the GM syncromesh oil. Their gear ratios are major differences between the Muncie M21 and the Muncie M20. The M21 and M22 are the same ratio wise. The second contributing factor has to do with getting Sep 23, 2018 · The 2. 55 rear gears and an M20 will take off in first gear like a car with 4. Here are some key factors to help you distinguish bet… Dec 11, 2021 · I have heard some say the M20 is junk but like the M22. Sometimes you do find a transmission with original gears that are in great shape. the M20 , M21 , M22 . There are several interesting features which are special in the 1965 M22. 10's and an M21/M22. Jun 22, 2016 · A: Zack, I am excited that you and your father are working on a project car together. They are for economy and street drivability and just cruising. The muncie transmission has no front seal unlike the Saginaw and the Borg Warner transmissions. 52:1. In 1967… Jul 8, 1999 · The M21 is a standard Muncie 4 speed. An M21 or an M22, while stronger in the case of the M22, will be a dog off the line unless you have a 3. It was installed in the Camaro, Chevelle, Corvette, El Camino, Firebird, Nova and many other classic GM cars. The side cover has seven bolts and two shift cams. Apr 27, 2023 · Cangialosi explains there were two basic mainshafts produced for the M20, M21, and M22 transmissions (see Input Shaft Identification chart). Get the Gaskets HERE: http://goo. It will not harm yellow metals. More Information on Muncie M20, M21 & M22 Transmissions. It was thought that the Corvette received the Muncie transmission first Mar 16, 2013 · i don't think there is any reliable way to determine if it's a 20 or 21 by the numbers. The early ones had a 2. 52:1 wide range B 2. 56:1 ratio is referred to as the M20. 56:1 ratio is commonly referred to as the M20. M. wrap tape around the input and output shafts, and scribe a line. Aug 31, 2020 · To tell an Muncie M22 from an M20, start by checking the gear ratios. Many Mar 2, 2015 · Since the 7/8-inch bore was pre-1966, it suggests that the M22 transmissions were for 1965 cars. 199 1st gear heavy duty box). Amsoil also has a manual transmission oil that is made for the older manuals, like the Muncie and ST10. The later 1966-1974 units had a 2. Probably will be the last time I put in a transmission by myself unless I get a lift some day. 20 first gear Rock Crusher M22. That’s no coincidence: To save costs and development time, Chevrolet used the T10 as a base design, adding stronger Nov 30, 2016 · The first contributing factor was which Muncie four-speed transmission was to be installed in a particular application: an M20, M21 or M22. ) Oct 29, 2015 · The second one is for a M20 and the third one for a M21. The code will tell you which particular year the transmission was built for. ahhhh!! Now I understand; When my M20 starts making loud whirring and grinding noises I can just tell people it's an M22 "ROCKCRUSHER" !! :) MJ How to Identify Muncie 4 Speed Transmissions. 42:1 Suffix 1st gear ratio A 2. The straighter angle was designed to produce less end loading of the gear train and less heat but created more noise, thus the nickname "Rock Crusher" was born. Muncie Transmission information D & L Transmission To order call 1-631-351-4837. The best way to see what you have is to open the case and count the teeth on the input shaft gear. A = 2. As stated above, the difference is when you hit 4th gear, the M20 falls off more RPM. This is on a 66 to 74 model year Muncie. 52 1st gear. A 100% original M22 is a rare beast, as most have had various gears replaced, and some M22's have been created by installing entire M22 gearsets in an M20 or M21 case. All wide ratio transmissions are designated M20 and close ratio transmissions are designated M21 or M22 depending on the gear set. Muncie also had a second close-ratio transmission coded M22 and known as the “rock crusher,” which was used behind performance big-block engines and in some Corvettes. This is how the Muncie countergear’s design evolved. Using these tips, you can confirm whether you have the right transmission for your Chevy and make informed decisions about any potential restorations or modifications. Muncie Transmission ID and Ratio Guide. Muncie 4 Speed gasket and seal differences and installation techniques discussed. Jul 9, 2017 · Common Codes. 90 to 4. The rings on the input shaft may not tell you either. Series: Gear Ratio 1st, 2nd, 3rd, 4th: Spline Ironically, the Muncie was designed based of of the T-10 using its same basic layout. 73 rear gear. 56:1 first gear. There are alot of names these parts get called. 20:1 ratio Sep 15, 2010 · Passenger side of the unrestored M22 transmission. anyone else and actually design and make several transmissions and a load of parts. They can handle 450 Ft. Find one of those, and modify it back to just a 4 speed. Muncie 4-Speed Transmissions: How To Rebuild & Modify. 1969-1974 codes include a suffix letter at the end to aid in identification of transmission ratios. Except the M22 has straight cut of the gears that have that whine that was popular to hear. Glean the basics and use them in your research. 56) first in the M20, but that could also be compensated for with a rear ratio change Oct 7, 2008 · The M22 transmission has a 20 degree helix angle on the gear set as opposed to a 45 degree angle found on the M20 and M21 and were made with a higher nickel alloy. A Muncie differs from a Saginaw transmission in that its reverse lever is in the tail housing, not the side cover. 5 M/T ET Streets which are essentially DOT legal drag slicks. M21 input = 26 teeth. They both have the same ratios beginning with a 2. The lower gear is the latest version of the early T10 and the upper is the Muncie M22. From what I know (which is not much) the M20 is wide ration and the M21 is a close ratio don't know what the M22 is. 52:1 ratio first gear and 1. 20 1st isn't as deep as the 2. M22: Known as the “Rock Crusher”, designed for high-torque applications. 1975 was the first year catalytic converters , smog pumps, and low horsepower were introduced. 20:1 close range Oct 9, 2020 · The stock M20 has a first gear with 2. oh, and they go for $500-$600. The choice of transmission was dictated by the engine size and rear-axle ratio. This is what makes the car hobby so great. M20 transmissions were also used in some muscle cars and other vehicles. The Muncie 4-speeds (M20, M21, and M22) are some of the most popular manual transmissions ever made and continue to be incredibly popular. Serial numbers from 1963 to 1966 included only the month and day. During prototype testing, this 7/8″ countergear pin was found to be the weak link in upgrading the Muncie transmission. I'm running an M20 behind a ~600HP SBC and a 3. 20 first gear is not ideal for street driving unless you have a fairly low gear in the rear end like 4. 52 (or 2. An extra heavy duty close-ratio version (M-22) was also offered on many of the big-block high-performance models. then engage first gear and rotate the output shaft a large number of revolutions (say 20 or 30) and count the number of times the input shaft turns. All 1963-65 M20 and M21 transmission used a 7/8″ countergear pin in all assemblies. gl/nTpY0HMy #1 BOOK ON MUNCIES IS: http://a The OEM Muncie 4-speed was aging, few clean used gearboxes were available, the demand for Muncie gearboxes was growing, and the after-market had an opportunity to make the Muncie better. 52 1st gear wide ratio M20, B=2. M21: Close ratio, for high performance. 20 1st gear close ratio M21, C = 2. The straight cut gears make the transmission stronger. One of the most common swaps involves a Muncie 4-speed. For close to eight decades, the company has produced quality power components and systems like the Muncie 4-speed transmissions (M20, M21 and M22). The Muncie Transmission in 1963. But the really great news was that it was actually a M22 Rockcrusher that the guy could have gotten $2k for. hngdsh vmm uumddn eznh kmpbw xgiek swxfiiud iwsqg vrhx rqpln