Borg-Warner T90

The Borg-Warner T90 was a common transmission found in 1946-1971 Jeeps. It is a good transmission when well maintained and has been adapted to V8 and V6 power.

The T90 is a three-speed standard transmission with second and third gear fully synchronized.

There were three versions of this transmission:

T90A1 – This version was used from 1946-1962 behind the “Go Devil” four-cylinder head and had a 7″ input shaft stick-out length with 15/16″ x 10 splines.

T90C – This version was used from 1963-1971 with the “Hurricane” four-cylinder engine. It has a 7″ input shaft stick-out length with 15/16″ x 10 splines. The case of the T90C is actually marked T90A. The only way to know if you have the T90C transmission is to confirm it came out of a post-1962 Jeep or pull the top cover and count the gears.

T90J – This version was used with six-cylinder trucks from 1952-1965. It has a 9.25″ input shaft stick-out length with 1.125″ x 10 splines.

All 4WD T90 transmissions have a 1.375″ x 6 spline output shaft. A 2WD version of the T90 was made, but is a rarity.

The factory service manual called for changing the transmission fluid every 12,000 miles with SAE 90W or 80W GL4 fluid. It is OK to use 80W-90 fluid, just be sure to not use any fluid labeled “Severe” and ensure the fluid is safe for brass synchros. Avoid GL5 gear oil.

Gear Ratios

GearT90A/T90JT90C
Reverse3.794.53
1st Gear2.793.34
2nd Gear1.551.85
3rd Gear1.001.00

Fluid Type and Capacity

LubricantSAE 90W GL4
SAE 80W GL4
Capacity1.25 qts (1.18L)
Avoid GL-5 lubricant, which can cause increased wear on the brass synchros found in this transmission

Other Specifications

Weight75lbs
Length8.80″
Height14″
Input Splines10
Output Splines6
Pilot Tip Widthunknown

Transfer Case Compatibility

The Jeep T90 came factory with the Jeep Dana Spicer Model 18 transfer case, and only the small input bore versions.

T90 was available attached to the Dana 20 in the 1962-1965 J Series trucks.

It is possible to join a T90 to the Dana Spicer Model 20 transfer case using the Novak kit here.

Engine/Bellhousing Compatibility

GM – Buick V6, Chevy Small Block V6 and V8 conversions are done with this transmission. The GM adapter can be found made by Novak here.

Ford – The T90 transmission is adaptable to Ford Pinto, Mustang II, Rangers, and other Ford Inline-4 engines. An adapter can be found made by Novak here.

AMC – The T90 transmission was never mated to AMC engines.

Write-ups and Tutorials

To Be Completed

Parts and Fluids

Engine Fluids

EngineFluid TypeCapacity
AMC 2.5L I4Above 0°F: 10W-30
Below 60°F: 5W-30
4.0 qts
AMC 4.0L I6Above 0°F: 10W-30
Below 32°F: 5W-30
6.0 qts
GM 2.5L I4Above 0°F: 10W-30
Below 0°F: 5W-30
3.0 qts
Renault 2.1Ltbdtbd
VM Motori 2.5Ltbdtbd

Transmission Fluids

TransmissionFluid TypeCapacity
Chrysler A904 3-Speed
Aisin-Warner AW-4 4-Speed
Chrysler 30RH 3-Speed
Borg-Warner T-4 4-Speed ATF Dexron II1.75qts
Aisin-Warner AX4 4-Speed75W-90 GL3 or GL4
10W-30 Motor Oil
2WD: 3.7qts
4WD: 3.5qts
Borg-Warner T-5 5-SpeedATF Dexron II1.75qts
Aisin-Warner AX5 5-Speed75W-90 GL3 or GL4
10W-30 Motor Oil
2WD: 3.7qts
4WD: 3.5qts
Peugeot BA-10/5 5-Speed
Aisin-Warner AX15 5-Speed75W-90 GL3 or GL4
10W-30 Motor Oil
2WD: 3.32qts
4WD: 3.27qts
New Venture Gear NV3550 5-SpeedMopar MT Fluid
SAE 30W Oil
3.3qts

Axle Fluids

AxleFluid TypeCapacity
Dana 3075W-90
75W-140 (towing)
1.26qts
Dana 3575W-90
75W-140 (towing)
1.75qts
Dana 4475W-90
75W-140 (towing)
2.00qts
Chrysler 8.2575W-90
75W-140 (towing)
2.11qts

Transfer Case Fluids

Transfer CaseFluid TypeCapacity
NP207
NP228/229
NP231
NP242

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4.0L

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