Ford T-5 questions
filed in 67 Mustang
Question: I am swapping in a T-5 5-speed transmission into my 289-powered ‘67 Mustang. I need some advise about which T-5 to try to get.
I have heard that the T-5s before 1986 have brass sycronizers and used gear oil and the ones after 1986 have cone syncros and run with ATF. Some people recommend getting the later version and some recommend getting the earlier version. There are probably other changes through the years that I am not aware of.
My car will be slightly modified over stock and won’t be used for drag racing. Although I am not looking for a race version of the transmission, I want a tough tranny that I won’t have to worry about breaking with normal aggressive driving. I would like some advice on what will break first in the T-5, what years are worse, and what modifications are recommended.
Answer: If this car is going to be used for drag racing, then it might make more sense to switch to a Tremec transmission, which is a direct replacement for the T-5 transmissions in the Mustang. I have broken so many T-5s myself due to drag racing and powershifting that the next tranny I buy will most likely be a Tremec. They can handle upwards of 400 lb ft of torque, versus the T-5 only handling 305 lb ft-even with the heavy duty T-5 out of the SVO catalog. The tremec is 25 lbs heavier than the T-5 but it is much beefier, it is actually designed based on an old Ford toploader tranny but with an overdrive 5th gear added to it. An ‘89+ tranny might work for you; they haven’t changed much since ‘89. Given than the 289, slightly modified, shouldn’t have any more torque than a 302FI things should be OK. After all, unless you spend a lot of time over 5-6K the next thing that will kill a tranny is drag racing and too much torque. I have seen used trannies for $400-600 with less than 40K on them. New ones (usually aftermarket) start at around $1100-1200.
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