New transmission designs came with new, unique pan shapes, and the general shape of the pan often paints a fairly clear picture of which automatic transmission you are dealing with. Before 1967, General Motors included extra information such as the plant code, shift code, and date of production on the ID tag. now = new Date Generally used in straight and V6 and small block engines. You can use a variety of stock and aftermarket shifters on any of the Muncie tailshaft housings. Like Cobalt said, it is very easy to mistake a 6 for an 8 in these castings. GM's goal with the Muncie four-speed was to produce a better shift employing larger synchro cones. So now that we have given you some insight into identifying the Chevy four-speed transmission, the next time you are scouring the swap meets or local Craigslist ad, youll have a better understanding of what you are looking at, and youll get exactly what you want. Some transmissions will have a code stamped onto them while others have a tag riveted to the case. CD-68-315953 This is when you have to remove the side cover to see what's inside. Muncie Transmission Identification. The staff has been amazing to work with and takes care of their customers better than any other company I have ever dealt with. My question is will this direct swap to a '81 with the 3 speed saginaw? Turbo 400 is the biggest, Turbo 350s and Powerglides smaller. Whats The Reason Enthusiasts Cant Get, Yes I Am A Dinosaur, And Why I Feel Electric Cars, Step-By-Step Birth Of A QA1 Adjustable Racing Shock, Readers Rig: Sterling Diesels Duramax-Powered C10, What I Learned Today With Jeff Smith Ensuring Wrist Pin Clearance, Corvette Enthusiasts Use Media To Share Z06 Delivery, Fenix Is A Next-Gen 69 Camaro With 1,180 Horsepower, Shop Tour: Brian Tooley Racing Expands To Be A One-Stop Shop, Moroso Anti-Roll Kit Is The Right Tool For The Dragstrip, Near where the shift linkage attaches to the body, Just above the housing on the right side of the pan, On the passenger side on a flange by the bell housing. A little engine degreaser and a wire brush often 1981-1990. The most common GM 4-speed transmission types or groups are Muncie, Saginaw, and Borg-Warner. In 1962, aluminum units were only used with the 327 engine, but by 1963, all Powerglides had aluminum cases. The Turbo 400 has a very distinct fluid pan. The Four are late model. Here's a typical Muncie gearset consisting of First, Second, and Third gear. The Turbo 400 was GM's heavy-duty three-speed transmission used from 1964 to 1990. In fact, 1963 is a standalone year because changes in this box came almost immediately for 1964, beginning with the front bearing retainer, which was aluminum for 1963 and became cast-iron in 1964. It was phased out of use and superseded by GMs 700R4 starting in 1982. GM 3 Speed Manual Transmission 3854728 for sale online | eBay The Muncies appearance, design, and operation did not change much during the transmissions use in GM production cars. If youre unaware, the production sequence is the last six numbers of your VIN. Main case casting numbers (when looking at the passenger side these numbers are upside down) 6273262, tail shaft housing casting numbers 3968035, Shifter cover casting numbers GM1 3952646. When other companies started making automatic transmissions in the 1950s, GM already had four in-house. Finding the ID tag can be extremely difficult on the Turbo 35o particularly because, its probably been lost. Manufacturer Part Number. if (theYear < 1900) The transmission pan is one of the most precise methods of identifying a transmission. Terms of Service. The classic Muncie four-speed transmission in all its many forms generally looks like this (this one provided by Anaheim Gear), though applications will vary in appearance. Joined: Dec 2, 2001 Messages: 26 Location: Midwest City USA. As long as you have the correct transmission shift levers, it should't be much to convert to the later trans, but I'd probably start with the Saginaw, given the choice. Generally able to handle up to 400 foot pounds of torque. Author: Alan L. Colvin. The 3-speeds were just as beefy and robust as their 4-speed counterparts. New Process Gear NP435 - 4-speed longitudinal transmission used in a select handful of 67-72 GM pickups The transmission codes are found on the Protect-O-Plate and in the following locations: . Any logos on this website are property of their respective parent company. Responding to market demand for a three-speed automatic, The Turbo-Hydramatic 350 was introduced in 1969 as a replacement to the Powerglide in Chevrolet cars and trucks with six-cylinder engines or low-horsepower V8 engines. Knowledge of your cars transmission system is helpful during repairs and car restoration projects. While the Chevy four-speed manual transmission was a staple in many muscle cars, even many of the Generals other car models were equipped with a manually operated gear selecting device. Comparison images courtesy of Hurst Shifters. document.write(theYear) We will safeguard your e-mail and only send content you request. 6. GM 3 speed ID | Page 2 | The H.A.M.B. The Muncie 4-speed transmission was used with many different GM models and engine combinations from 1963-1974. We will safeguard your e-mail and only send content you request. Whether youre trying to repair your transmission or rebuilding a project car, its crucial to identify the transmission type. A = Jan, B = Feb, C = Mar, D = Apr, E = May, H = Jun, K = Jul, M = Aug, P = Sep, R = Oct, S = Nov, T = Dec. Example: 19N500001. How to identify chevrolet gmc manual transmissions But the other numbers don't match the extension or sidecover casting numbers. This stamping is usually alpha code indicating the source of the trans followed by several numbers indicating specific month & day the trans was assembled. You have to decode these simple codes to read and understand the information. This machined flat area has serial numbers by three Numbers and ending in another Letter (or two). Author and technician Paul Cangialosi tells us the original U.S. patent for the Muncie four-speed was filed on November 29, 1957, and approved May 7, 1963. When introduced in upper-level Chevrolet models in 1950, the Powerglide represented the first automatic transmission offered by the Big Three. Differentiating is easy, as the Muncie has seven bolts holding the side cover, and the Borg-Warner uses nine. To add a little confusion to the mix, there were Borg-Warner Transmissions that feature aluminum cases and cast-iron side covers. Saginaw 3 speeds were built in both Saginaw, Michigan & Munchie, Indiana. All rights reserved. Summit Racing Equipment inventories all kinds of cast-aluminum and steel bellhousings for the Muncie. Next, carefully raise the vehicle with a jack. NOT every company stands behind their work. If you are installing your transmission that was purchased from Monster Transmission, our sales and support staff is here. For a better experience, please enable JavaScript in your browser before proceeding. You cant simply look at your classic car and identify the type of transmission it uses. Prior to 1967, transmission ID numbers contained the plant prefix code, month and date of production (expressed numerically) and a shift code (D = Day, N = Night). How to identify and decode chevrolet manual transmissions. The 1969 and later models use a bolt to secure the linkage to the transmission. Two are early style side covers. In the 1970s, virtually all Muncie four-speeds had 26-spline input shafts. I have four transmissions, which I need to identify, before I can proceed. than other boxes. If you have a 1963 Muncie that needs an input shaft bearing retainer, all is not lost if you can't find the 1963 aluminum bearing retainer. A=M20 B=M21, C=M22). GM produced many transmission variants over the years, we included some of them here, but our main focus is identifying the fluid pans for Powerglide, Turbo 350, and Turbo 400. Post-67 Example: P9E03 - (P = TYPE, 9 = year (1969), E = Month, 03 = Day of Month), Month code: (NOTICE this is NOT in alphabetic order) The early GM Hydra-Matic transmission served the 1940-1968 Oldsmobile models. This is the M21 10-spline input shaft with a single groove and the applicable 27/22/19/17-tooth countershaft. You can use things like the pan material, length, and shape to identify it. Removal of the front bearing cover is where disassembly begins. Lets take a brief look at the backstory and origins of each transmission, and how you can visually identify them as well as locate ID tags and identification numbers. Sep 20, 2004 #4 CRAZYREDNECK77 Member Sep 20, 2004 67 The M-22 has "straight cut" gears. 2023 Power Automedia. Because the Muncie has so much in common with the T-10 and even similar Saginaw boxes, it is easy to get this guy mixed up with non-Muncie units. On the Turbo 350, the VIN will be stamped on either the drivers side housing (near the shifter), on the right side of the housing just above the pan, or on a boss behind the bell housing flange on the passenger side of the transmission. 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. The Novak Guide to the GM Muncie SM465 Transmission We promise not to use your email address for anything but exclusive updates from the Power Automedia Network. Remove the side cover and forks for a look at the geartrain. Gm manual transmission identification numbers. Discussion in '1947-1954' started by Blueflame236, Dec 15, 2012. . The vehicle identification number (VIN) is a unique identifier for each vehicle (VIN). This is because the transmission lengths are the same and the positioning of the cross member can be easily modified, you only need to change the transmission mount, add transmission cooler lines, and update the shift indicator to a Turbo 350 pattern to complete the exchange. The M22 Rock Crusher would come later to accommodate the heavy twist of Chevrolet's big-blocks in the mid-1960s. GM Casting Numbers a usually four digit letter/number combination separated like this: X XX X. Take the following steps to access and place the transmission pan: Most manufacturers stamp the transmission identification numbers on the transmission housing. Looking Up The 17-Digit Vehicle Identification Number. Besides the transmission identification, it also helps to figure out which options was the car ordered with by using a VIN decoder tool. We are dedicated to giving you the technical support you need, when you need it! This is what "The World's Best Chevrolet Club" is all about! 3L80 stands for three gears, longitudinal mount (rear-wheel drive), and the 80 signifies that it can handle 8,000 lbs. GM manual transmission identification. General Motors used different transmission pan shapes and bolts for its models, so this method requires some knowledge of the pans. If you examine the 1966-'70 wide-ratio M20 input shaft, there are two grooves cut amid the 10 splines. This is usually a 7 digit number and each letter/number is about 1/2" tall. M38 Standard Turbo 350 manufactured from 1976 to 1981. Vehicles leaving the factory with an axle ratio of 3.55 and numerically lower gears, typically incorporated a wide-ratio transmission. You can check online auto repair websites, as some have free decoders. Last edited: Dec 16, 2012. . Yes, there is a serial number on a transmission. Show More Show Less. VCCA members have access to a list of over 50 Technical Advisors who can help you with your car. The constants in decoding the transmission ID number are the date the transmission was produced. General Motors has produced a myriad of versions of its fabled automatic transmissions over the years, although three models make up the bulk of pre-ECM GM slushboxes; the. These numbers can be found on the transmission case, and the first letter in this series of numbers is going to tell you exactly which Saginaw transmission you are looking at. It was a matter of economics when Chevrolet needed a four-speed manual transmission for the Corvette in the mid-1950s. The one on the right is an aluminum-case Powerglide. It also uses the same vacuum modulator as the Turbo 350. How To Identify Chevy Four-Speed Transmissions Chevy Hardcore NEWSLETTER - SIGN UP FREE! On the Turbo 400, the VIN is stamped on a machined surface just above the pan on the drivers side. 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. After 1967, GM switched things up and changed the code structure. I definitely recommend a look at these transmissions, you've got to have a look. This was used in A-body and F-body cars and Corvettes into the early 80s. Muncies are the hot tip, since they usually were used with high performance engines. The M22 was designed as a road race transmission, and the straighter angle of the gear teeth produced less heat and less end-loading of the gears. The next set of numbers you will find helpful are on the flat part of the Distributor Deck. The transmission pan is a wealth of knowledge because it has various inscriptions concerning the transmission. The Muncie four-speed, like the T-10, is a side-loading transmission. It's a light duty version of the THM400, has ABSOLUTELY NO RELATION to the THM375B, and was found in 1972 to 1976 full-size cars. Quick Decoding - Chevelle Stuff MV4 This code identifies your turbo 350 as a C model, which had a locking torque converter. He tells us both the M20 wide-ratio and M21 close-ratio transmissions were first offered in 1963 . When repairing or restoring your Chevrolet car or truck, identifying the transmission youre running is a key element to avoid the automotive version of quicksand. You can find the assembly date code, casting number, and source serial number for vehicles GM manufactured after 1961. Off of the left side of trans: GM 3845122 H254 Thanks. GM transmission identification explained | REREV Cangialosi tells us all M20 and M21 transmissions were produced with both 10- and 26-spline input shafts. These grooves were cut into the input shaft so assembly line workers at the plant could easily identify which input shaft should be installed in a particular unit. Search transmissions by vehicle's VIN, License Plate, or Year/Make/Model information. On modern models, you can tell which type of manual transmission a car has by looking at the top of the gear shifter. The numbers you are looking for are stamped (about 1/4" high) and usually a Letter followed Engine Casting Numbers Explained 1954-1962 Chevrolet, Serial Number/Engine Type/Series Designation, On the flat part of the Distributor Deck you will find a stamped Serial Number. The 1963-'65 M20 input shaft will not have grooves. Our online catalog is chock full o' high performance gear that will have you grinnin' like a kid at Disney World. On the THM200-R4 the VIN is stamped onto the housing towards the rear of the pan, on the drivers side. The M22 Rock Crusher 26-spline input shaft sports a wider gear for greater torque capacity. Notice: Any comments posted herein do not necessarily reflect the official position of the VCCA. M33 This standard Turbo 350 code identifies it as a standard Turbo 350. Cases are either small-bearing (1963) or large-bearing (1964-'74). Transmission Stuff * Manual 3-speed transmissions * Muncie 4-speed Casting Numbers/Decoding/Identification * Powerglide * Turbo Hydramatic 350 * Turbo Hydramatic 400 * 200-4R/700R4 Overdrive * GM Transmission lengths & oil pan * Automatic transmission operating temps * TH350/TH400 Speedometer Gears Frames * Chevelle Frames Trim Tags Not only is the diagram below helpful for identification purposes, but is a great visual source to see if you have enough room for a swap you might be contemplating. Muncie or Saginaw 3sp | NastyZ28.com Cangialosi explains there were two basic mainshafts produced for the M20, M21, and M22 transmissions (see Input Shaft Identification chart). Of course, restorers and rebuilders will tend to re-stamp the date code to suit a particular restoration. the years that you narrowed it down to when you deciphered the Casting Numbers to the right. and traction is enhanced, you can figure on eventually breaking the transmission. The muncie reverse lever is in the extention housing, and the cover has 7 bolts. This patent number, according to Cangialosi, can be found cast into most Muncie four-speed main cases. The Turbo 375 was modified to accept the Turbo 350 driveshaft yoke. I live in Covington, Tennessee and I just had my Monster Transmission installed in my 2001 Dodge Ram and I'm completely happy with it. The 700R4 became the 4L60 and so on. Not only were they both popular transmissions in muscle cars and Corvettes, but many were even used after the muscle car era. He digs all flavors of automobiles, from classic cars to modern EVs. the angle of the gear teeth. The length of the unit can also tell you a few things. fileslib. 3L80 - The 3L80 is a renamed THM400, used in the early 1990's. From the outside, you should be able to make out the number on the metal dash plaque by looking through the glass. Outside that, you can push in your clutch and hold the brake. We'll send you the most interesting Chevy Hardcore articles, news, car features, and videos every week. On the left is the M20 countershaft and 10-spline input shaft. The large-bore Muncie came into production in 1964-'65 and became the standard from then on through the end of production in 1974. MX2 Another 350C code. It is also a cast iron case. GM Turbo 400 TH400 Transmission 3 Speed Transmission. Please click Accept Cookies to continue to use the site. . 18L165790 ~David PS ..I would think pictures of all 3 could help us if you could post some. Another quick way to identify a Turbo 400 is to look at the kick-down mechanism. 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Muncie transmissions from 1971-'74 have the larger 32-spline output shaft. The basic design and operation theory of the gearbox changed little during that time, though several design upgrades and modifications were made during the total production run. This list includes some GM transmissions. 4L80 - An overdrive model of the THM400. From complete engines, to torque converters to Monster in a Box, we've got all your HP needs covered. The materials used in case construction of a Muncie/Chevy four-speed mean that if you find one of these gear boxes in a shed or barn, the Muncie will probably be smooth and covered in grease and/or oil, while a Borg Warner or Saginaw transmission will usually be coated in a light layer of rust. The Muncie four-speed transmission was heralded by many as anindestructible four speed used by General Motors, and found its way into many different car models, behind various engine combinations between 1963 and 1974. (700R4 & 4L60) Casting numbers on the case and extension housing. Gm manual transmission identification numbers - Tesla Community The 26-spline input shaft came into production later in the 1970s for the M20 and M21. In the early 90s, GM rebranded all of its transmissions. According to Koval, the easiest way to identify an automatic transmission, though, is by transmission pan shape. Muncie 4-speed transmissions can be distinguishedvfrom the style of the transmission arm attachment. Tweet Become a VCCA member! THM200-R4 - Used in GM rear wheel drive cars with the 3.8 V6, 305 & 350 Olds and 301 pontiac from 1981 to 1989. theYear=now.getYear() THM350 - Medium duty 3 speed trans used from 1969 to 1989, Used in Buick, Olds, Pontiac and Chevrolet cars and Chevy & GMC light trucks until 1987. Jointly developed by Chevy and Buick, it is also known as the CBC (Chevrolet-Buick combined) 350. S = Saginaw 3-speed A = 68/69 L6 Torque-Drive K = McKinnon 3-speed C = Cleveland Powerglide . The casting number 3925660 denotes this as a 1968 1970 Muncie with a 1-inch cluster shaft. The easiest way of knowing your GM transmission is by using a VIN decoder. Check through the information for your transmission identification. The close ratio gearboxs generally came with 3.73+ gear ratio'ed cars. You can find out from the specifications or by checking the foot pedals. Slide under the car and locate the transmission. General Motors has produced a myriad of versions of its fabled automatic transmissions over the years, although three models make up the bulk of pre-ECM GM slushboxes; the Powerglide, the Turbo-Hydramatic 350 (Turbo 350), and the Turbo-Hydramatic 400 (Turbo 400). Making this separation makes the job easier. In 1974, the two-speed box then went to the great scrap heap in the sky. A mechanically robust transmission, it was used in other General Motors vehicles as well. 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. The data will help you to identify the transmission system. 3925656 is the casting number for the saginaw used in 68-75 at least. The constants in decoding the trans ID number are the date the transmission was produced. Prior to 1967, transmission ID numbers contained the plant prefix code, month and date of production (expressed numerically), and a shift code (D = Day, N = Night). . (AODE & 4R70W). Use the owners manual to find information such as the transmission pan length, shape, and more. Older vehicles are quite different because theres a lot of variety when it comes to transmission systems. PDF 3-speed Transmission I.d. Chart 4-speed Transmission I.d. Chart severely powerful (high torque) big-block engines. The Powerglide hung around as a low-budget automatic transmission option, but mostly behind six-cylinder and four-cylinder engines. Apart from numbers, General Motors transmission ID tag has codes. 13. You can find the serial number on the bottom left of the transmission data plate. Many enthusiasts mistakenly refer to all Muncies as Rock Crushers, and this is just not appropriate. When repairing or restoring your Chevrolet car or truck, identifying the transmission youre running is a key element to avoid the automotive version of quicksand. Expert advice on car parts, maintenance, and repair. The Saginaw four-speed box is quite similar to both the T-10 and Muncie four-speed transmissions. Muncie (left) Saginaw The Muncie was originally a stronger alternative to the T-10 and Super T-10 because it could take the torque. GM Transmission ID Guide: Powerglide, Turbo 350, And Turbo 400 Dave Cruikshank is a lifelong car enthusiast and an editor at Power Automedia. All transmissions with a 26-spline input shaft used a 32-spline output shaft, and all those with a 10-spline input shaft were paired with a 27-spline output shaft. 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). It was phased out of use and superseded by GMs 700R4 starting in 1982. Many GM trannys had the VIN stamped on the maincase on the flange where it attaches to the tailshaft, but some of the later Saginaws had a pad machined into the case just for stamping the number. THM375 - This transmission is a derivative of the THM400 sharing the external appearance of the 400. Theres a good number of vehicles that make use of both manual and automatic transmissions. The "kick down" switch locations for the Turbo 400. The Muncie four-speed was produced in two ratios: the wide ratio (M20) and the close-ratio (M21). When it shifts from 1st to 2nd its got a really smooth shift and it puts a smile on your face. 20. hey Bob .I wish I could help out with your numbers on the trannys. For example, replacing a Powerglide with a Turbo 350 is an easy swap. Input the VIN in a decoder and search. The casting number 3925660 denotes this as a 1968 - 1970 Muncie with a 1-inch cluster shaft. 1965 and Newer. Due to this, the box tends to Generally able to handle up to 400 foot pounds of torque. There is no leaking coming from the front seals, rear sears or oil pan. Build your own custom newsletter with the content you love from Chevy Hardcore, directly to your inbox, absolutely FREE! If you have a project car from Chevrolet, Buick, Pontiac, or any other GM brand, youll want to identify the transmission. All Prices are in USD. THM250 - Used in small 4 cylinder cars (Vega, Sunbird, Monza) from 1973 to 1981 and some Nova/Camaro/Chevelle 6 cylinders in 1974 & 75.