what are the differences in 4cyl and 5oh t5's?

  • Sponsors (?)


the 4cyl input shaft is smaller and when using it with a V8, requires a pilot bearing from a saab. The V8 trans has the larger input shaft and can be turned down in order to be used with a 4cyl.
The torque rating on the V8 is slightly higher but I wouldn't try to "build" to the strength of a V8 trans. I had a 4cyl trans behind a 351w that ran 7.8 in the 1/8th. They will take a lot of power but none of them can handle loads of wheel hop or missed gears.

Several companies sell rebuild kits to make your own Z spec trans, which is probably a good alternative.
 
V-8 vs. 4-cyl T-5's - Differences:

1. Gear Ratios - The 4cyl tranny has a lot closer ratios, and the 5th gear isn't really much of an extra gear compared to the V-8 tranny.

2. Input Torque rating - The 4-cyl tranny has a slightly lower input torque rating than the V-8, but can still handle V-8 power, look at the Turbocoupe and SVO trannies.

3. Input pilot diameter - a special pilot is required for using a 4 cyl tranny behind a V-8.

the casing, syncro's, blocker rings, thrust bearing, and main shaft are the same, with the exception of the input bearing retainer, the V-8 trannies use a larger bearing and the retainers are not interchangeable.

Having a 4-cyl tranny behind a V-8 is like having gears out back, my bud has one in his mild V-8 and it's like he has 3.73's.

Having a V-8 tranny behind a 4-cyl is like have 1.73 or so gears out back, it's too steep of a ratio and keeps the engine dogged out all the time, unless you have 4.10's or better out back.

As mentioned, there are "z" spec kits out there to upgrade the T-5, although i don't know if they make them for the 4cyl trannies.
 
ok, i have a tranny from a 90 4 banger...
i ordered the pilot bearing - motormite part for 80's saab

i know i need to get a bellhousing for a v8

heres the questions
in the summit magazine there is a 10.5" clutch and pressure plate assembly that comes with a throwout bearing - this should work right, except for the bearing?

can i get any 5.0 clutch system?
85coupe said the throwout bearing was different size - so where would i get a new throwout bearing and steel retainer? since v8 ones wont fit if i understand correctly
local ford dealer?

thanks for all the help
 
yeah you should be ok with any clutch for a later fox mustang. The only thing is the flywheels have different balances so be sure to get the right one. I used a stock replacement clutch for an 87 5.0 with my 351w coupe and it worked great. The throwout bearing that comes with the clutch kit should be the right one.

If you want a steel retainer you can get them out of jegs/summit easily.
 
Jonstantine said:
ok, i have a tranny from a 90 4 banger...
i ordered the pilot bearing - motormite part for 80's saab

i know i need to get a bellhousing for a v8

heres the questions
in the summit magazine there is a 10.5" clutch and pressure plate assembly that comes with a throwout bearing - this should work right, except for the bearing?

can i get any 5.0 clutch system?
85coupe said the throwout bearing was different size - so where would i get a new throwout bearing and steel retainer? since v8 ones wont fit if i understand correctly
local ford dealer?

thanks for all the help

The throwout bearing is the same, it's the tranny front bearing retainer that is different. I don't think that there is a steel bearing retainer available for the 4 cyl trannies. Yes, the Summit clutch kit will work fine, just be certain you get the right imbalance. Pre 1982 5.0's use the 28 Oz imbalance and '82 and later use a 50 Oz imbalance flywheel and damper. The 351W uses the 28 Oz setup.
 
ford racing 10.5", all 3 parts come in one package for that price

but since im using a 4cyl tranny with a v8, should i use a stock clutch so that less strain is put on the tranny?

*by imbalance, your strictly refering to the flywheel, correct?
 
Correct. I was referring to the flywheel imbalance, 28 or 50 Oz are the two possibilities.

As for the clutch, 160 isn't that bad at all for a completely new set.

don't worry about the clutch size, if the tranny is going to break it's going to break either way.
 
I put a steel front bearing retainer on my 4cyl T5... i think yer all on crack about the front bearing being a different size... :shrug: The casing is the EXACT same for all Borg Warner ford spec T5's... from 4 cyl to cobra... hence you could take a 4 cyl T5 and send it to g-force and they'd pimp it out like a $5 hooker... but only for like $1500... hehe.