Domestic Truck Transmission Identification Guide
by Mike Weinberg, President, Rockland Standard Gear Inc.
One of the difficult problems facing most transmission shops is the identification of manual transmissions. To be able to order parts and create a valid sales quote for their customer, the shops have to know what they are working on. Stick shift transmissions comprise about 20 percent of the market; so most shops are very familiar with automatic units and have difficulty with manual trans identification. The following guide is published to provide some basic information to lead you in the right direction as to what transmission you are working on. Space limitations do not leave us with room to list every manual transmission you may encounter, but the units listed here make up the most common units found in domestic trucks and sport utility vehicles.
Great care needs to be taken in identifying manual transmissions. Many units are produced with the same design externally, but have different ratios to work with the many engines found in these vehicles. Obviously a transmission with ratios for a 2.3-liter, 4-cylinder engine will not be durable if used in a V8 application. Manual transmissions designed for gasoline engines will have poor drivability if used with a diesel engine, and vice versa. A real world nightmare occurs when you get a vehicle in the shop that has had a previous repair and the repairing shop did a junkyard swap. The only problem is that they put the wrong unit in and the customer is now in your shop to get it repaired correctly. In a typical scenario all ID tags are gone from the unit. If you order parts to repair the unit that is in the vehicle you will fix this unit, but the ratios will be wrong for the vehicle it is in. This is why tooth counts, bearing numbers, and case casting numbers are extremely important not only to order parts, but to insure that this is the right unit for the engine-chassis combination you are repairing. We have seen countless instances where shops have correctly fixed a unit only to have it fail quickly because someone had put a 4-cylinder unit where a V8 should be. When working on standards try to obtain as much information as you can and to preserve all ID tags with the unit.
Four Speed Transmissions
Side mounted Overdrive (SMOD). Synchronized in all forward gears, with top loaded cast iron case. Used in 1978-84 Ford light duty pickups and vans. Similar in appearance to the Ford "top loader trans" but has overdrive 4th gear. Three shift rails mounted to the left side of case. This unit was produced for cars also but with lighter duty bearings and gear train. Produced in 2 and 4 wheel drive versions.
Also known as Single Rail Overdrive (SROD). Has an aluminum case with shifter turret mounted on extension housing. Synchronized in all forward speeds with 4th being overdrive. Used in Ford light duty pickup trucks 1980-83. There is also a passenger car version of this unit with lighter duty bearings and gear ratios. Produced in 2 and 4 wheel drive versions.
Top loaded 4 speed with 4th being overdrive. Aluminum case and shift tower. Found in Ford F100-250 light duty trucks from 1984-85, also known as a TOD (top shift overdrive) Produced in 2 and 4 wheel drive versions.
New Process A833
4-speed transmission, with all forward speeds synchronized. Manufactured in both direct drive and overdrive models. 10 Bolt shift cover mounted on left side of transmission case. Early models had iron cases and late model cases are aluminum. Case length measures 10 5/8 . Used in Chrysler passenger cars 1964-80, Dodge trucks 1976-85, and 1981-86 General Motors trucks. GM models may be identified as RPO code MY6 Produced in 2 and 4 wheel drive versions
New Process 435
Top loaded heavy-duty 4-speed transmission with cast iron case and extension housing and aluminum shift tower. 2nd through 4th gears are synchronized with 1st and reverse using non synchronized sliding gear. Found in 1963-85 Dodge trucks, 1964085 Ford pickup trucks and stripped chassis, 1964 to 72 GM trucks, and International Harvester and Navistar trucks from 1964-85. produced in both 2 and 4 wheel drive versions.
(shown without extension housing)
Top loaded heavy-duty 4-speed transmission with cast iron case, extension housing and shift tower. Synchronized in 2nd, 3rd, and 4th. Available in 2wd and 4wd drive versions. Cases have PTO openings on both sides. 1st and reverse gear are non-synchronized. 1st gear is a deep reduction low gear and shift knob may show H pattern with Low, 2,3,4. Used in GMC and Chevy trucks and stripped chassis from 1968-85
Borg Warner T18
(shown without extension housing)
Top loaded heavy-duty 4-speed transmission with cast iron case and shift cover. Case casting number is 1301. Synchronized in 2nd,3rd, and 4th, with 1st and reverse non-synchronized. Available in 2 and 4wd drive versions. Easily confused with earlier BW T98 and T98A models. Care should be used when ordering parts to make positive ID of unit. Used in Ford trucks 1956-73, Jeep models from 1965-85, and International 1965-73.
Borg Warner T19
(shown without extension housing)
Top loaded heavy-duty 4-speed transmission with cast iron case and shift cover. Case casting number is 1309. Easily confused with T18, but the T19 is synchronized in all forward speeds. The T19 has a single step reverse idler gear while the T18 has a 2 step reverse idler. Available in 2 and 4 WD models. Used in Ford trucks 1974-85 and International trucks 1974-85.
Five Speed Transmissions
Aisin Warner AX5
5 speed fully synchronized center support type of transmission with aluminum case and extension housing. Available in 2 and 4 WD models, and with external and internal hydraulic slave cylinders. Used in Jeep vehicles 1984 and up with gas engines and 1984-87 Jeeps with diesel power.
Aisin Warner AX15
5 Speed fully synchronized center support transmission with aluminum case and extension housing. Similar in appearance to AX5 but larger with heavier duty gear train. Available in 2 and 4wd configuration. Found in Jeep vehicles 1990 and up and Dodge Dakota trucks 1992 and up.
Borg Warner T5
All aluminum 5 speed top loading transmission. All forward gears synchronized. Early design has brass synchronizer rings while later "world class design" uses paper lined rings and tapered bearings on countershaft. Model number located on ID tag attached to extension housing bolt starts with 1352. Built in 2 and 4 WD versions. Used in Jeeps 1982-87, General Motors S10 2wd trucks with mechanical speedometer, GM S10 1989-95 with electronic speedometer, and GM 4 X 4 S10 1983-95. This unit is also found in Astro Vans with 2.8 or 4.3 V6 engines. Tremec Corporation bought the design from Borg Warner and now manufactures this unit.
Peugeot BA10 (AX18)
Light duty aluminum 5-speed transmission available in 2 and 4 WD models. "Suitcase design where the main case splits apart lengthwise for disassembly. Used in 1987-89 Jeep vehicles with 4.0-liter engines. Note location of shifter and how it retained; as there are two designs. Additionally there is 5 or 6 bolt mounting flanges for the transfer case on 4wd models.
New Process 2500 (New Venture 535)
Light duty 5 speed fully synchronized aluminum case transmission with 4 bolt top cover. Available in 2 and 4wd models. The shifter is located behind top cover on top of transmission. This is a center support type of transmission.
5-speed transmission fully synchronized in all forward gears. Available in 4wd only. Bell housing, case and extension housing are aluminum with removable bell housing. The extension housing measures 10 _" and there is a 12 bolt steel bottom pan on unit. This unit is manufactured by Mitsubishi and is used in Ford Ranger and Bronco II vehicles 1985-89. On left side of case is a red ID tag giving Ford part number and unit serial number.
5-speed transmission synchronized in all gears (including reverse). Built in 4wd version only. When used in 2 WD vehicles there is an open dummy transfer case used. Aluminum bell housing, case and extension housing with removable bell housing. The extension housing measures 13" in length and there is a 12 bolt-steel bottom pan on unit. This unit is manufactured by Mitsubishi and is used on Ford Ranger and Bronco II vehicles from 1988-92. A red id tag located on left side of case shows Ford part number and unit serial number.
D50 is a common industry name describing a series of Mitsubishi manufactured 4 and 5 speed transmissions, which are found in Dodge and Mitsubishi small trucks. The models include the KM131 4 speed transmission used in Dodge D50 trucks from 1983-85, the KM132 5speed, 2wd, transmission used in Dodge D50 trucks from 1983 and up, and the KM145 5 speed, 4wd transmission used in Dodge D50 trucks from 1983 to present. These same transmissions are found in Mitsubishi trucks also. These units are similar in design to the FM146 except that the bell housing integral to the main case. There are many design levels of this unit and it is extremely important to get tooth counts and input bearing numbers before ordering parts. There should be a model number and alphanumeric code stamped on the bell housing which helps to identify the units.
New Venture 1500
5 speed fully synchronized transmission, with bell housing integral to aluminum transmission case. Similar in design and appearance to HM290, 5LM60, and NV 3500 series transmissions, but slightly smaller. Requires some special tools to rebuild. Used in 1996 and up GM S10 vehicles with 4 cylinder or 2.8 liter engines.
5 speed fully synchronized transmission with the bell housing integral to the aluminum case. There are four design levels of this unit. It started life in 1988 as an HM290 found in GM trucks, and was re-designated 5LM60 with early and late designs. Hm290 and 5LM60 units each have 4 shift rails. The unit was completely redesigned as a 3500 with a single shift rail. Due to all the design variations it is critical to positively identify which model trans you are working on in order to get the right parts. This unit is built in both 2 and 4WD versions. This series of transmissions requires some special tools for rebuilding. These transmissions are found in full size GM trucks from 1988 and up, S10 trucks from 1990 and up, and 1994 and up Dodge Dakota V8 Ram trucks.
5 speed, fully synchronized top loaded heavy-duty transmission. Cast iron case and extension housing with aluminum shift cover. Unit weighs 200 lbs.. Found in GM full size trucks and stripped chassis 92 and up, and in 1994 and up Dodge V8 trucks. There is also a 4500HD model that is used in 1994 and up Dodge trucks behind the V10 diesel engines. This unit MUST use Castrol Syntorque Fluid for lubrication fill.
(no picture available)
Heavy-duty 5 speed fully synchronized transmission with cast iron case and aluminum shift cover. Used in Dodge trucks from 1989-93 behind Cummins diesel engine. Due to design limitations and extreme expense of parts to repair, you will do the customer a favor by arranging to swap this unit for an NV4500 which has much higher level of durability.
1988 to present Mazda built, fully synchronized 5-speed transmission, found in Ford Ranger and Explorer trucks. Aluminum case with integral bell housing, aluminum extension housing, and aluminum shift cover. Available in 2 and 4WD models. ID decal on left side of case. The shift cover was modified in 1995 to have a taller shift cover and neutral position switch in cover was eliminated. In 1998 the stub stick in shift cover was changed to accept shift lever with groove on right side. Used with 2.3L,2.9L,3.0L, and 4.0L engines. Ratios will vary with engine size and so will starter locations on bell housing.
Mazda built 5 speed fully synchronized transmission found in 1988 to present Ford F150 series trucks and full size Broncos. Aluminum case, extension housing, and shift cover, with integral bell housing. Very similar in design to M5R1, but larger with shift lever located in center of shift cover. Available in 2 and 4WD versions. 1995 and later models have top cover reverse light switch moved to forward corner of shift cover. In 1996 case is changed to accommodate modular motor (4.6L), with starter bolt pattern being triangular. In 1999 the case was changed for 4.2L 4wd drive vehicles. The case is very similar to earlier style units with case length shorter on 4.6L and 4.2L models.
ZF S542 and S547
The S 542 Heavy duty 5 speed fully synchronized transmission with aluminum case and extension housing. The bell housing is integral to the case. Shifter is mounted to small shift cover on top of unit. Built in 2 and 4WD versions. This unit is used in Ford F250, F30, F450, and Super duty trucks from 1987-94. The Super duty model has a mechanical park brake assembly mounted to the extension housing. The S542 is found behind 300, 302, 351, 460, and diesel power plants. The S547 unit is used behind the same engines from 1995 to present. Both units have PTO covers on each side of case. On the left side of the case is mounted and ID tag, which gives the Ford Part number, the ZF part number and the unit serial number. Great care should be taken to properly identify the unit you are working on as both the S542 and S547 appear to be the same and with the great variety of ratios available, it is easy to order the wrong parts.
A light duty fully synchronized 5-speed transmission. The case and extension housing are aluminum with a removable bell housing. This unit is used in 2000 and up Jeep wrangler vehicles with 6 cylinder engines.
Six Speed Transmissions
An extremely heavy-duty unit with 6 forward speed. All gears are synchronized. This unit has an aluminum case with integral bell housing, a center support, and rear case. This unit is built in both 2 and 4WD versions. The S650 is found behind diesel engines of 1998 and up Ford Super duty and stripped chassis up to a gross combined weight of 26,000 lbs. The unit weighs in at 230 lbs. A unique feature of this unit is an internal oil pump driven off the front of the countershaft that circulates the lube to a trans cooler. An easy way to identify this unit is by the cooling lines mounted to the case as found in automatic transmissions. Id tags are mounted on the left side of the main case.
This very heavy-duty 6 speed is used in heavy-duty Dodge trucks from 1998 on. All forward speeds fully synchronized, this unit has an aluminum bell housing, cast iron case and extension housing, with top mounted shifter. Available in both 2 and 4WD versions, this unit weighs 360 lbs. The transmission can handle vehicles with a gross combined weight of 26,000 lbs.