Editing General Motors transmissions

{{develop}} ==Overview== First, a transmission is a way of applying torque from an engine through a differential to a wheel, causing forward (or reverse) motion of a standing body. This article will concern itself with the different types of transmissions used by General Motors, and their physical and mechanical properties. ==Types of transmissions== ==Standard== ==Three speed== [[Image:64_Nova_3_sp.jpg‎]] [[Image:64_Nova_3_sp_number.jpg‎]] [[Image:64_Nova_3_sp._shift_levers.jpg‎]] From a 1964 Nova 342 Saginaw. ==3-speed manual overdrive units== ===How overdrive works=== The governor powers the solenoid in the mid 20's MPH, you have to let up on the gas pedal to let it shift up. When you push the pedal to the floor the kickdown switch cuts off the power to the solenoid and temporarily cuts off power to the ignition coil so the engine stops running for a second or two. This lets the spring on the solenoid retract and shifts out of overdrive. When you drive less than the governor speed setting in overdrive it cuts off power to the solenoid. If you are going up a hill and the car does not coast the solenoid will not retract and you will still be locked in overdrive. When you are in overdrive you can not go backwards. This was called the "hill hold" feature. The pull out T-handle is used to lock up the trans into regular 3-speed mode. This is useful when pulling a trailer uphill and important when going down hill. If the handle is pushed in you can coast and not have any engine braking. When you were cruising and in overdrive second gear and some one pulled along side and wanted to race you could stick your toe under the gas pedal and push down on the kick down switch to gear down before hitting the gas and opening all three carbs. When you wire in a toggle switch to operate the relay to power the solenoid you could shift it into overdrive in any gear and not have to be above the governor speed in first gear. Just like driving a big truck with a two speed rear end. Just remember you have to let up on the gas to let it shift up into overdrive and when you turn off the switch you also have to let up on the gas to let the spring retract the solenoid to shift out of overdrive. If you leave the switch on and are in overdrive you can not shift into reverse and you cannot roll backwards. ===Borg Warner OD wiring diagram=== [[File:Od-wiringdiagrm.jpg]] <br style="clear:both"/> ===Rebuilding the Borg Warner overdrive=== *Article, [http://www.classictruckshop.com/clubs/earlyburbs/projects/t85n/rebuild.htm ''Rebuilding the Borg Warner Overdrive Unit''] ==Four speed manual transmission identification and description== <gallery widths=230px caption="Three common 4-speed transmissions"> Image:Muncie_M20_4_speed.jpg|'''Muncie M20''' wide ratio‎, the reverse lever is in the extension housing, and the cover has 7 bolts. While looking at the cover, 3rd/4th gear lever is on the left. 1st/2nd gear lever is on the right. Image:Saginaw2.jpg|The '''Saginaw''' reverse shift lever is on the cover, and the cover has 7 bolts. Image:Borgwarner.jpg‎|The '''Borg Warner''' has a 9 bolt cover. </gallery> ===Muncie 4-speed=== ====Identifying Muncie M20 series transmissions==== The external differences between the three Muncie 4 speed transmissions can be deceiving. If the cover is removed, the pitch of the gears can be seen. In order to tell the difference between an M21 and M22 definitively, look at the helix angle on the gearset. M20 and M21 have a steeper pitch, where the M22 will have a less aggressive pitch. M22s are NOT straight-cut or 'spur gears'. [[File:Muncie gearsM20-21 VS M22.jpg|thumb|400px|left|]] <br style="clear:both"/> Link to a Muncie page showing [http://www.dandltransmission.com/muncieratio.html Muncie gear ratio, spline counts, exploded view, parts list, etc.] from D&L Transmissions. ====Muncie info from AutoGear:==== AutoGear designed the Italian gear program with Antonio Masiero (now Euroricambi). Today there are ways to get over 20 ratios between their M22 and Dragrace M23 programs. AutoGear also makes a 'Muncie Replacement' and replacement parts for GM's Muncie 4-speeds. To make a strong transmission, use a SuperCase and an Iron Midplate. These 2 things will add a tremendous amount of strength to the transmission. If possible, do not re-use a gearset from the factory case. Factory cases are known to stretch over time and slowly pull the mainshaft gears and countershaft gears out of parallel. This means the gears are 'worn' into each other and will not mesh correctly with new gears or a new case. This leads to a lot of noise and a short lifespan. Use a 26 spline input, hopefully with an oilseal and you could go 27 splines on the mainshaft if its a street car, but it will be stronger with 32 splines on the output. In most cases there is no sense in using an M21; there are no premium quality gears, and by changing the input and cluster, you get an M20 which has a deeper 1st gear and is better suited to street cars these days. A SuperCase retails for less than $300 and an iron midplate is less than $100. Most shops charge $250 just to repair a used case. With respect to the M20, M21, and M22; these are technically GM 'RPO' production codes. If you wanted a wide ratio 4-speed it was RPO 'M20' However this code also meant wide a ratio Saginaw or a T10 4-speed, depending on the application and year. Additionally, M22's are not all 26 spline inputs and 32 spline outputs. The spline count is YEAR specific, not MODEL specific. There are probably more 26 spline input, 32 spline output M20s in the world than any other Muncie 4-speed. The GM Muncie is stronger than the T10 or ST10. The reason GM went to the T10 '''after''' the Muncie 4-speed was dropped in 1974, is because the T10 is less expensive to produce and the horsepower levels had dropped significantly by then. Some guys do impressive things with the T10; however, Richmond Gear was bought out and at the present time (ca. 2012), the availability of T10 parts is getting worse. ====Muncie reference material==== *[http://www.yearone.com/updatedsinglepages/Id_info/muncie.asp Muncie 4-Speed Identification] *[http://www.nastyz28.com/2gcog/trans.html Camaro Transmission Information and Restoration] *[http://www.yearone.com/yodnn/tech/VehicleInfoDecoding/GMMuncie4SpeedDecoding/tabid/349/Default.aspx GM Muncie 4-Speed Decoding] *[http://www.muncie4speed.com/munciecat.pdf 1963-1974 Muncie 4-speed assemblies, gears and parts] *[http://www.teufert.net/trans/muncie.htm Muncie ID] ===Saginaw 4-speed=== *[http://www.teufert.net/trans/saginaw.htm Saginaw 4-speed ID] ===Borg-Warner 4-speed=== ====Borg-Warner reference material==== *[http://www.autogear.net/pdfs/T10%20booklet.pdf 1957-1963 Warner T10 4-speed (early) assemblies, gears and parts] *[http://www.hotrodders.com/forum/attachment.php?attachmentid=47519 T10 manual] ==Five speed== ==Six speed manual== GM used three basic 6 speed manuals over the years: *ZF S6-40 *Borg Warner/Tremec T56 *New Process/New Venture NV5600 in trucks ===German ZF S6-40=== Starting with the 1988-'96 Y-body (Corvette), a German ZF 6-speed was used, designated S6-40. It was stout and reliable, but its limited use and short production run didn't support wide aftermarket solutions. In fact GM didn't even stock service parts for the transmissions, instead opting to provide remanufactured units instead of repairing them. Although it ended up costing GM less in the long run, it was a concept not warmly received by the public. Early models were rated for 400 ft-lbs, and later models were rated to 450 ft-lbs. ZF 6-speed ratios are as follows: *Reverse - 2.50 *First - 2.68 *Second - 1.80 *Third - 1.29 *Fourth - 1.00 *Fifth - 0.75 *Sixth - 0.50 [[File:CutawayZF S6 40.jpg|thumb|left|300px|ZF S6-40 transmission]] <br style="clear:both"/> ===Borg Warner/Tremec T56=== Starting with the 1992/1993 GM F-body (Camaro, Firebird, Trans Am) the six speed was a Borg Warner-designed, Tremec-built T56 transmission. Although the basic design, case, and internal operation were the same, three different ratio gear sets were available in GM applications. In 1993, F-body cars were equipped with two optional rear axle ratios: 2.73 and 3.23. Beginning in 1994, all T56 cars used the same ratio gear set regardless of rear axle ratio. 1992-1993 T56s with the lower gear sets had a slightly lower torque capacity in the 350 lb-ft range while 1994-later (high) gear sets reduced the side loads on the case and were rated to 450 lb-ft. T56 use continued like this until 1997 when it also started being used in the Y-body (Corvette) as a rear-mounted transaxle, and continued on in F-bodies behind the LS1 until the end of their production. Of note is the fact that all T56 transmissions share an interchangeable main case; even those found in Holdens, Fords, Vipers, and Aston Martins. What differs is the front adapter plate, tail shaft housing, shifter, and input/output shafts. Internally, there were some interchangeable differences, like the type of shift forks and synchronizers used, but for the most part all T56s are built on the same stout center section. Gear ratios are as follows: ====T56 transmission ratios- 1993 F-body with 2.73:1 axle:==== *Reverse - 3.28 *First - 3.36 *Second - 2.07 *Third - 1.35 *Fourth - 1.00 *Fifth - 0.80 *Sixth - 0.62 ====T56 transmission ratios- 1993 F-body, 3.23:1 axle:==== *Reverse - 3.28 *First - 2.97 *Second - 2.07 *Third - 1.43 *Fourth - 1.00 *Fifth - 0.80 *Sixth - 0.62 ====T56 transmission ratios- 1994-current GM production:==== *Reverse - 2.90 *First - 2.66 *Second - 1.78 *Third - 1.30 *Fourth - 1.00 *Fifth - 0.74 *Sixth - 0.50 [[File:Tremec dimensions.jpg|thumb|400px|left|T56. Note the multiple options for shifter mounting positions.]] <br style="clear:both"/> ===T56 transmission torque specs=== *Backup lamp switch 20 ft/lb *Clutch actuator cylinder bolt 71 in/lb *Clutch housing bolt 37 ft/lb *Control lever handle bolt 18 ft/lb *Gear select/skip shift solenoid 30 ft/lb *Reverse lockout assembly bolt 13 ft/lb *Reverse lockout solenoid 30 ft/lb *Shift control bolt 13 ft/lb *Shift control closeout Boot Bolt 18 in/lb *Shift control knob 27 ft/lb *Transmission bolt 37 ft/lb *Transmission drain/fill plug 20 ft/lb *Transmission mount bolt 38 ft/lb *Transmission mount nut 77 ft/lb *Transmission support bolt 66 ft/lb *Vehicle speed sensor bolt 89 ft/lb ===NV5600=== Designed by New Venture, this stout truck six speed is up to the task of living behind engines like the Duramax and 8100 Vortec. For obvious reasons it has little application in hot rods due to its huge size, excessive weight, and truck-like gear ratios. [[File:NV5600.jpg|frame|left|NV5600]] <br style="clear:both"/> ==Automatic transmissions== ===Hydramatic=== The history of the Hydramatic transmission began back in 1932, when it was introduced by Cadillac as the "shiftless transmission". For more historical information, see [http://en.wikipedia.org/wiki/Hydramatic Hydramatic transmission] at Wikipedia. The scope of this article is mainly centered around the transmissions of the '60s to present date. However, if there is interest in prior years it can certainly be included. ==General Identification== ===Transmission identification by pan shape=== [[Image:Pan_id.jpg‎]] {| style="background:yellow" ! Image Number !! Transmission(s) !! Pan Bolts |- ! 1 | Aluminum Powerglide | align = "center" | 14 |- ! 2 | TH200 (Metric), TH200C (Metric) | align = "center" | 11 |- ! 3 | TH250, TH250C, TH350, TH350C, TH375B | align = "center" | 13 |- ! 4 | TH375C, TH400, TH475, 3L80, 3L80HD | align = "center" | 13 |- ! 5 | TH200-4R | align = "center" | 16 |- ! 6 | TH700-4R, 4L60, 4L60E | align = "center" | 16 |- ! 7 | 4L80E | align = "center" | 17 |} ===Transmission dimensions=== [[Image:Transmission_dimensions.jpg‎ ]] ===Typical application information=== [[Image:Transmission_guidelines.jpg‎]] == Two speed automatic== ===Powerglide=== The Powerglide transmission was used in Chevrolet vehicles, even Corvettes. The 2 speed automatic used in Buick, Olds and Pontiac vehicles was known as the Super Turbine 300 or ST-300. The ST-300 transmission was similar to the Powerglide but few parts were directly interchangeable. The ST-300 was also produced with a variable pitch torque converter. This converter could change stall RPM with an electric solenoid inside the transmission that was activated by a switch usually mounted on the throttle linkage. ===Torque-Drive=== This was a low cost Powerglide-based transmission that used a manual valve body. It had to be manually shifted into high and down to low. It was sold under RPO MB1, and cost about $100 less than a Powerglide. It was available with 4 cylinder and 6 cylinder engines. ==Three speed automatic== [[File:1972 th350 id.jpg|thumb|200px|TH350 accumulator with ID. "72" is year, "152" is a calibration code, "KE" is application code (link to application codes below)]] ===TH350, TH350C, TH375B=== the TH350 trans was built in 5 different lengths. Two were 4x4 applications. Tail housing lengths of the two wheel drive were 6 inch, 9 inch and 12 inches. The 12 inch length is not very common. It was used mostly in Buick AND Oldsmobile station wagons. ===TH350 model ID codes=== {| |[[File:1972 th350 id.jpg|thumb|200px|TH350 accumulator with ID. "72" is year, "152" is a calibration code, "KE" is application code (link to application codes below)]] |[[File:TH350 ID governor cover.jpg|frame|left|ID stamped into governor cover]] |} Codes for 1969-'72 TH350 transmissions are located on the accumulator; 1973-'81 TH350 codes are on the governor cover. Listings of the transmission application codes can be seen '''[http://www.teufert.net/trans/trans.htm HERE]'''. <br style="clear:both"/> ===TH400 (3L80), TH375C, TH475 (3L80HD)=== 1987-up 3L80HD is the HD version of the TH400 found in light trucks. It has 27 spline output shaft and is 34.5" long overall in 4x2 version. Found cast on the bell housing in medium size letters is 'HD'. The TH400 transmission was used between 1964-1990. 1987 was the year the transmissions were renamed using the alphanumeric designations. ===TH400 model ID codes=== A listing of the two letter model code found on the metal ID tag is '''[http://www.teufert.net/trans/t-400.htm HERE]'''. ==Four speed automatic== ===TH2004R=== The TH2004R transmission is the same length as a 6 inch tail housing TH350 transmission. The TH2004R requires a TV cable hook up at the EFI or carb with the correct geometry for correct operation. ===TH700R4 (4L60)=== ===4L60E=== 4L60E is an electronic shifted and pressure controlled version of the 700R4 / 4L60 transmission. ===4L80E=== 4L80E is a full electronic controlled and shifted transmission with similar design and strength to the T-400 trans. Early 4L80E and TH400 shared some parts that could be swapped. In 1996 the 4L80E has some design changes in lubrication circuits. You must be very careful when replacing gear train parts in late design 4L80E. ===6L80E, 6L90E=== General Motors 6 speed automatic. While some parts swap between the 6l80 and 6l90, there are differences to watch out for, such as a longer case length for the 6l90 as well as larger output and spline count. Verses the 32 splines of the 6l80. [[File:6L90 trans.jpg|thumb|left|330px|6L90 transmission.]] <br style="clear:both"/> ==Bellhousing bolt patterns== The following is a list of GM bellhousing patterns. This section is based on wiki article [http://en.wikipedia.org/wiki/List_of_GM_bellhousing_patterns List of GM bellhousing patterns]. ===Chevrolet pattern=== [[image:Chevy_bell_pattern.jpg|thumb|300px|Chevy bolt pattern]] * Chevrolet small and big block V8 * GM 90° V6 (200/229/4.3L) * GM [http://en.wikipedia.org/wiki/GM_Iron_Duke_engine Iron Duke] RWD inline 4 (early RWD variants, later versions may use a FWD pattern, and have two possible starter locations) * Jeep with GM Iron Duke inline 4 2.5L/151cid (1980-'83). These use a MOPAR Torqueflite 904 automatic transmission with an integral Chevrolet bellhousing. Do not confuse with later AMC 2.5L engine that uses the GM metric pattern (see below). * Chevrolet inline 6 (1963-up) * Chevrolet 153 inline 4 (Chevy II, pre-Iron Duke, includes the Vortec 3000/181 industrial/marine crate engine) * GM [http://en.wikipedia.org/wiki/GM_Atlas_engine Atlas engine] ===Buick, Oldsmobile, Pontiac (BOP) V8 pattern=== [[image:BOP_bell_pattern.jpg|thumb|280px|BOP bolt pattern]] * Post-1965 Buick/Oldsmobile/Pontiac RWD V8 * Buick big block and 1963-up small block V8 * Buick pre-3800 90° RWD V6 * Jeep [http://en.wikipedia.org/wiki/Buick_V6_engine#Dauntless Dauntless 225cid oddfire V6] (1967-'74) * Cadillac cast iron V8 after 1967 (1968-'85 368, 425, 472 and 500cid V8) Starters are on the driver side on Olds 350-455 and Pontiac, and the passenger side on Cadillac 425/472/500 and Buick 225/231/300/340/350/400/430/455. <br style="clear:both"/> ===Uni-bell pattern=== This photo shows a multi-pattern case. Both the BOP and Chevrolet pattern on the same bell housing. [[image:Multi_pattern_bell.jpg|thumb|left|300px|Uni-bell pattern]] <br style="clear:both"/> ===GM metric pattern=== [[File:GM 60deg V6 bellhousing.JPG|thumb|200px|GM 60 degree pattern]] The GM metric pattern is also called the GM ''small corporate pattern'' and the ''S10 pattern''. This pattern has a distinctive odd-sided hexagonal shape. Rear wheel drive applications have the starter mounted on the passenger side of the block. The 2.2L S10/Sonoma had the starter located in the same position as front wheel drive cars. A rear wheel drive bellhousing is displayed at right. * GM [http://en.wikipedia.org/wiki/GM_60-Degree_V6_engine 60 degree V6] 2.8/3.1/3.4/3.5/3.9L V6 (also used by AMC) * [http://en.wikipedia.org/wiki/Buick_V6_engine Buick V6] 3300/3800 V6 * Cadillac [http://en.wikipedia.org/wiki/Cadillac_V8_engine#HT-4100 4.1/4.5/4.9L V8] * Isuzu 3.5L DOHC V6 * GM [http://en.wikipedia.org/wiki/GM_Iron_Duke_engine Iron Duke]/Tech-4 2.5L inline 4 * GM [http://en.wikipedia.org/wiki/GM_122_engine "122"] 1.8/2.0/2.2L inline 4 * AMC/[http://en.wikipedia.org/wiki/Chrysler_2.2_%26_2.5_engine#2.5 Chrysler 2.5L inline 4] engine found in Jeep Cherokee, Comanche, Wagoneer, CJ, Wrangler, and Dodge Dakota * GM [http://en.wikipedia.org/wiki/GM_LS_engine#5.3_L_2 5.3L LS4] V8 * GM [http://en.wikipedia.org/wiki/Northstar_engine_series#LX5_.28Shortstar.29 3.5L LX5 V6] "Shortstar" <br style="clear:both"/> ===Northstar pattern=== [[File:Northstar2.jpg|thumb|300px|Northstar pattern, somewhat resembles GM 60 degree pattern]] Nearly identical to the GM small corporate/metric pattern, except that the starter is located between the cylinder banks, and the lower right bolt hole is moved outward by roughly one inch. It shares the distinctive odd-sided hexagonal shape of the 60 degree metric pattern. * Cadillac [http://en.wikipedia.org/wiki/Northstar_engine_series#Northstar_series Northstar V8] * [http://en.wikipedia.org/wiki/Oldsmobile_Aurora Oldsmobile Aurora] L47 V8 <br style="clear:both"/> ===GM Ecotech=== * GM [http://en.wikipedia.org/wiki/GM_Family_II_engine#Ecotec Ecotech] DOHC inline 4 [[File:Ecotec2.jpg|thumb|center|400px|Ecotec pattern]] <br style="clear:both"/> ===Buick and Rover aluminum V8 pattern=== [[File:215 bell.jpg|thumb|300px|Buick/Rover aluminum V8 pattern]] *1961 through 1963 Buick/Oldsmobile/Pontiac [http://en.wikipedia.org/wiki/Buick_V8_engine#215 215 aluminum V8] **Buick 198 cid V6 *1967 through 2004 [http://en.wikipedia.org/wiki/Rover_V8_engine Rover 3.5, 3.9, 4.0, 4.2, and 4.6L aluminum V8] (based on the 215 Buick aluminum V8) <br style="clear:both"/> ===Cadillac V8, pre-1968 pattern=== {| |[[File:331ID49-54.JPG|thumb|300px|center|Cad 1949-'54 331 ci pattern. Note cast in partial bellhousing]] |[[File:CADblockID.JPG|thumb|300px|center|Cad 1955-'64 331, 365, 390 cid pattern]] |} Early Cadillacs manufactured from 1949 to 1954 used a "round top" bellhousing partially cast into the block casting. Around 1955 the bellhousing pattern was revised until the BOP bolt pattern was adopted. <br style="clear:both"/> ==Speedometer== ===TH350, TH400, manual speedometer gear ID=== *[http://www.teufert.net/trans/speedo.htm Speedometer colors/tooth count] *[http://www.teufert.net/trans/speedo-gears.htm Speedometer gear usage chart] ==Fastener threads== LX engine tranny to block bolts are metric: M10 x 1.5. Using SAE bolts on a GM transmission mount after about 1978 will strip the mount threads. GM converted to metric mount bolts about 1978 even though most of the rest of the transmission bolts did not change until the TH700R4 and TH4L80/E came out. TH350 and TH400 transmission mount, speedometer, and solenoid bolts went metric about 1978. All other bolts were SAE to the end of production. TH200C, TH2004R, TH700R4, and later transmissions used metric fasteners. ==Resources== *[[Transmission identification]] *[http://www.teufert.net/trans/tranny.htm Tranny info] ;Crankshaft Coalition Wiki articles *[http://www.crankshaftcoalition.com/wiki/Category:Transmission Transmission category] [[Category:Transmission]] [[Category:Good articles]]

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