Installing a T-5 in a Tiger
(No Cutting Required!*)

Dan, (#64) pulling the cork on a GT350 and a Camaro at the VARA Willow Springs Race!

An Article by Dan Walters
August, 2001

Page 2

Tech Data:

.... The T-5 was used in an amazing variety of vehicles starting in 1981. The T-5 was originally intended for the 4 and 6 cylinder world. The early T-5s had 1st gear ratios from 3.50 to 4.03. Had Borg-Warner known the T-5 would end up behind V8's they may have designed it stronger. Only after going to a 2.95 1st gear was the T-5 deemed able to handle V8 power. The Mustang started using the T-5 behind the V8's in 1983. Here is a list of the different ratios the Mustang V8 used:

1983 1984 1985-89 1990 After Market
1st Gear 2.95 2.95 3.35 3.35 2.95
2nd Gear 1.94 1.94 1.93 1.99 1.94
3rd Gear 1.34 1.34 1.29 1.34 1.34
4th Gear 1.00 1.00 1.00 1.00 1.00
5th Gear 0.73 0.63 0.68 0.68 0.63

.... Improvements in the T-5 allowed a wider ratio to be used behind the V8. The 2.95 is known as the "close ratio" and the 3.35 is known as the "wide ratio" There are 4 different 5th gear sets available. The overall 5th gear ratio is determined by the trans you start with:

5th Gears "Close Ratio" (1st 2.95)
0.80 0.73 0.63 0.59
"Wide Ratio" (1st 3.35)
0.92 0.83 0.72 0.68

NOTE: The 0.80 5th gear sets are hard to get. It was standard on VERY few OEM apps. The 0.73 is difficult to find in the Ford spline, as I do not believe it was made for a Ford application. Unfortunately, the 0.92 and 0.83 are similarly rare.

.... The T-5 is used to the best advantage in a Tiger with lower than standard (2.88) rear axle gears. A Tiger with a 3.31 axle ratio and close ratio T-5 with a 0.80 5th gear has both first and top gears equivalent to a standard Mk I Tiger with a 4.21 axle for first gear and a 2.65 axle for top gear. The 2.95 1st gear and 0.80 5th gear combination is the closest ratio T-5 available and is recommended for performance applications. The .63 5th gear usually drops the RPMs too low if you have an axle ratio lower (numerically) than about 3.73. The 3.35 1st gear 0.68 5th combination, although common, is not very desirable with the possible exception of the '90 and up version with a 0.83 revised 5th gear set and a 2.88 axle. If you desire better acceleration in first gear, and low RPM cruising, regardless of rear axle ratio, the T-5 is the answer.

"World Class" & Torque Capacity:

Initially, the OEM V8 T-5 had a torque capability of 285 ft.-lb. with a 2.95 1st gear ratio. A production change occurred in 1985 model year, and the 1st gear ratio was changed to 3.35 along with a bearing update. Torque capability was not significantly changed but the wider ratio helped to get the Mustang moving in 1st gear. This update ( primarily the bearing update) is known as the "World Class" by Ford. I do not believe other users of the B-W T-5 used this designation. The OEM Mustang T-5s built between 1985 and 1988 have the worst reputation as being weak, primarily because of the wide ratio design. Material changes in 1989 improved the T-5. The first "Motorsport" T-5 used a 2.95 1st gear and was rated at 305 ft.-lb. the next revision was rated at 325 ft.- lb. The current "Motorsport" version is also the "World Class" design with the last of the T-5 updates and is rated for a CONTINUOUS 330 ft.- lb. New T-5s are being manufactured by TREMEC, who acquired the rights for the T-5 from Borg-Warner.

Wide Ratio Tiger 4 spd. Top Loader:

If you are satisfied with the 4th gear 72 m.p.h. at 3,000 r.p.m. of the stock Tiger 4 spd.Top Loader set-up, with 2.88 rear end, then the low and intermediate gear performance can be significantly improved with the use of the Ford wide-ratio gear set swap (input shaft, layshaft, and 2nd and 3rd gear parts) to replace those in your present close ratio box, without changing the 2.88 rear axle.


.... * The bolt-in "NO CUTTING REQUIRED" T-5 conversion for the Tiger is capable of being done. I will help anyone with a bolt in kit (NOT CHEAP), but THEY need to come up with an AMC 2 wheel drive T-5 tail housing and other parts from the AMC trans.

Here is the information on the AMC tail housing, and other interesting observations:

  • The particular AMC tailhousing needed for the "no cutting" installation has the Tail Housing casting number 13-52-066-901 ( on left side of tail housing). Information supplied by Jim Morrison is that this housing (tailshaft) was used on 2 WD 1982-1983 AMC Concord or Spirit.
  • The AMC Trans should have a tag on one of the tail housing bolts with the number 13-52-001 (the B-W part number for the complete trans, the actual number is 13-52-000-001 but the tags didn't use the 000 on it.)
  • Note, this trans WAS THE FIRST VERSION OF THE T-5!
  • The last new T-5 I bought was 13-52-253, the models are numbered sequentially and chronologically.
  • The 1983 Mustang V8 T-5 is 13-52-034, The 1984 Mustang V8 T-5 is 13-52-065.
  • The Chevy Chevette used the T-5 and the part number is 13-52-005.This, to my knowledge, is the only other T-5 ( 2 wheel drive) to put the shifter in the same location as the AMC, but with a shorter tail housing.

Call Dan Walters@ (909) 792-3568 for information on our services.

End of Article

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