Fox T-Bird/Cougar Forums

Technical => Drivetrain Tech => Topic started by: 88cougarxr7 on April 17, 2006, 10:54:08 PM

Title: rear axles
Post by: 88cougarxr7 on April 17, 2006, 10:54:08 PM
would there be any advantage to a mustang rear axle out of a 2.3 or 3.8 car? and what would be a good rear axle to get for 5.0l that would make it a little quicker but still day to day driveable with decent milage... or are those 2 things that dont mix...
Title: rear axles
Post by: Haystack on April 17, 2006, 11:00:10 PM
they dont mix the best, Most people say 2-3 mpg worse with 3.73's, and I am soon to find out. Also, it wont make it faster per say, but it would give it alot better seat of the pants feeling.
Title: rear axles
Post by: thunderjet302 on April 17, 2006, 11:21:26 PM
I have 3.73 FMS gears and Traction Lock in mine and yes it is faster. The higher lower (numerically higher) gear set increases torque multiplication and does make the car faster. I would say it trimed about .3-.5 of a second off my 0-60 times. The car does feel much stronger but as a trade off you won't have the top end speed you do with 3.08s or 2.73s. The gas mileage isn't that bad, about 2-3 mpg off what it was with 2.73s but because of the better gearing I have the tendency to hit the gas harder to feel the acceleration :D
Title: rear axles
Post by: 88cougarxr7 on April 18, 2006, 05:04:45 PM
what is a good car to get one from?
Title: rear axles
Post by: thunderjet302 on April 18, 2006, 05:45:18 PM
Turbo Coupe had 3.73 gears and traction locks if they were auto cars. You'd have to convert to rear discs to install the rear though. I just had my rear end rebuilt and the gears I wanted installed.
Title: rear axles
Post by: SLEEPER T-BIRD 87 on April 18, 2006, 06:02:56 PM
Quote from: Haystack
they dont mix the best, Most people say 2-3 mpg worse with 3.73's, and I am soon to find out. Also, it wont make it faster per say, but it would give it alot better seat of the pants feeling.



i gained quite a few MPG's with an aod going from a 2.73 to a 3.73
Title: rear axles
Post by: slowfoxbird on April 18, 2006, 07:10:45 PM
Quote from: SLEEPER T-BIRD 87
i gained quite a few MPG's with an aod going from a 2.73 to a 3.73


Me too, I guess because the engine does not haved to work as hard to get going in the city.
Title: rear axles
Post by: Thunder Chicken on April 18, 2006, 07:16:47 PM
That's good news. Hopefully I'll realize the same gains with an AOD and 3.55's :D Gas here just hit $1.17/liter, and I'll bet it'll be over a buck and a half by the end of summer...
Title: rear axles
Post by: kingcars on April 18, 2006, 09:14:39 PM
Wow, gas here in NC is getting close to $3 per gallon.  :yuck:

I just got some 3.27s ready to be put into my 88 5.0 Tbird; I think it's a perfect mid range gear for gas mileage and acceleration.  I also have a 7.5in rear end, btw.
Title: rear axles
Post by: 88cougarxr7 on April 18, 2006, 09:50:30 PM
what about a rear end from a stick turbo coupe?
Title: rear axles
Post by: Thunder Chicken on April 18, 2006, 10:30:49 PM
Quote from: 88cougarxr7
what about a rear end from a stick turbo coupe?

What year? All pre-87 TC's had 3.55 gears in a 7.5" rear. In 87-88 the stick TC's had a 3.55 8.8" rear (this is the rear I'm installing in my car, hence the AOD+3.55 mentioned above) while the auto had 3.73's in an 8.8" housing. Ford did this by way of apology for crippling the auto TC's with 155 horses (versus 190 for the stick).

Your 88 XR7 should already have a locking 8.8", so unless you need disc brakes there's no advantage to swapping in a TC rear. You'd be better off just installing gears and rebuilding your traction lock

Quote from: Kingcars
I just got some 3.27s ready to be put into my 88 5.0 Tbird; I think it's a perfect mid range gear for gas mileage and acceleration. I also have a 7.5in rear end, btw.

I installed 3.27's into the 7.5" locking rear I had in my '87 Sport. IT made a bit of a difference, but nothing ground shaking. OF course I also added a 2.5" off-road true dual exhaust system at the same time so I probably gave up a bit of bottom end torque, so the 3.27's likely made up for that. I got my gears out of an '87 V6 'Bird.
Title: rear axles
Post by: thunderjet302 on April 19, 2006, 12:20:36 AM
:iagree:

If you already have a 8.8 then just change the gears and rebuild the Traction Lock.
Title: rear axles
Post by: Haystack on April 19, 2006, 04:05:49 PM
btw, I have only found one out of many 88's with 8.8's, so you will still have to crawl under and check. I ygot my 3.73's out of a mark 7 turbo (so carmen dosent get pissed at me I would put down desiel, although  i think I spelled it right,... I dunno)but that is with a 7.5 rear. Oh well, some modivation for when my engine gets all beffy
Title: rear axles
Post by: Thunder Chicken on April 19, 2006, 04:46:17 PM
Is it OK if I get pissed off that you misspelled "motivation"? ;)

And no, you spelled "diesel" wrong. Having spent the last five years in a shop called "Diesel and Auto Electric" building cop cars I rather think I know how it's spelled. It's on all my paycheques :D

...But don't trust me, use the spell checker.

I agree on the 8.8" thing though - Ford seemed to make things up as they go along back then