rearend installed!

[The Mach Says]

SVTSNAKE:

I was wondering if either of the shops that worked on your installations had any opinions or comments on the Ford 31-spline Differential unit you had installed. Reason being, is that I originally planned on purchasing the EATON unit, but it is currently on National backorder. Hence, I may end up just going with the FORD unit.

Is it comparable to the the Eaton unit, despite it being over $150 less? Is it a GOOD, durable unit as far as you or they know? Just looking for reviews/opinions.

Thx in advance,
JC

[jbrad88]

I have been running a modified ford posi for a long time with no problems. The posi has an extra clutch per side and the s-spring is a gm part ( a little stiffer spring than the ford part ). I had it re-built after 7 years of hard racing abuse. Spyder gears were pitted from all the racing so I had it re-built and no problems since then (@ 5 years ago now). It is a lower cost option that works...

[SVTSnake]

Both shops said that the Ford Posi is just as good as the Eaton. They are both rebuildable and use basically the same clutch packs. I don't think it is worth the extra money for the Eaton, but thats me. Lets face it, Cobra owners are putting down anywhere from 400-700 HP on these Posi's with no problems. The weak link in the Cobra drivetrain is the half shafts, not the posi. The Ford posi you buy is the 03-04 Cobra posi, minus carbon fiber clutches...

[CA Lightfoot]

Originally posted by SVTSnake
For those that have been following this thread about my troubles with my rearend buildup and the whine from the rear after it was done, I can officially say that my rear is whine free!

Superior here in MD took care of the problem today. Not only was the backlash set wrong, the shims were in backwards and the carrier was so tight in the pumpkin, that it took myself and Dave to get it out. Unbelievable! Anyhow, I replaced the gearset just for good measure, 2.5 bottles of Amsoil Series 2000 75/140, no friction modifier, and I can tell you that the only noise you can hear now is some tire noise! Dave and his helper were 1st class, and I have no problems recommending them over anyone else here.

:THUMBSUP: :LAUGH:

A few weeks back I watched "Horsepower TV"; they did a rear build-up on a 90's(?) Mustang convertible. 31-spline, 3.73, and an interesting electronically-controlled Auburn diff (http://www.auburngear.com/oemdifferentials/ected/).

Especially interesting was installation of the shims to get the right amount of backlash (measured before-and-after with some kind of dial/meter contraption). They said "it would howl like a banshee" if the backlash was wrong. Took several tries to get it right.

[tbl01]

Sorry to hear about your woes at larocca's.

I had larocca do my rear axles and gears, Also installed lowers.

No gear whine, no damage to lugnuts or rims.

[Chaucer]

Originally posted by SVTSnake
Both shops said that the Ford Posi is just as good as the Eaton. They are both rebuildable and use basically the same clutch packs. I don't think it is worth the extra money for the Eaton, but thats me. Lets face it, Cobra owners are putting down anywhere from 400-700 HP on these Posi's with no problems. The weak link in the Cobra drivetrain is the half shafts, not the posi. The Ford posi you buy is the 03-04 Cobra posi, minus carbon fiber clutches...

What is the part number for the Ford Posi?

[M1 Stang 04]

im new to this gear thing, can anyone explain what exactly does 4.10(or any other number) mean and whats the advantage of having it?

[Chaucer]

Originally posted by Chaucer
What is the part number for the Ford Posi?

bump

[The Mach Says]

Originally posted by Chaucer
bump

Send a PM to NitroStang...............I just bought it from him. Or you can always look it up at www.gefracing.com

JC

[M1 Stang 04]

somone i know has i think either 4.10s or 4.30s on theirs, and they claim its not that good because their top end is only 96mph in the 1/4. they said if anything to go with 3.73s, any comments/suggestions?

[Jester]

Originally posted by Chaucer
bump

M4204-F-318

Ford 31 spline traction lok.

[Jester]

Originally posted by M1 Stang 04
somone i know has i think either 4.10s or 4.30s on theirs, and they claim its not that good because their top end is only 96mph in the 1/4. they said if anything to go with 3.73s, any comments/suggestions?

12.745@107.40 in the 1/4 mile for me. The someone you know doesn't quite know...

[M1 Stang 04]

ha, sounds good to me (your comment that is)

what is the best gear for daily driving, ocassional racing, and track testing? ive been told by people on here that the 4.10s or 4.30s are perfect.

[Chaucer]

Originally posted by Jester
M4204-F-318

Ford 31 spline traction lok.

Thanks.

[Jester]

Originally posted by M1 Stang 04
ha, sounds good to me (your comment that is)

what is the best gear for daily driving, ocassional racing, and track testing? ive been told by people on here that the 4.10s or 4.30s are perfect.

Take your pick. I think I will try 4.30's the next time I have my rear serviced, not to say that I'm not happy with the 4.10's. They are both great gears for this car!

[starscream]

Originally posted by M1 Stang 04
im new to this gear thing, can anyone explain what exactly does 4.10(or any other number) mean and whats the advantage of having it?

In case you're still wondering, it refers to how many times the driveshaft rotates as compared to the the wheel. Ex draveshaft rotates 4.10 times for the rear wheel to do one revolution. This is accomplished by changing gear size. Think of the back wheel on a 10 speed or mountain bike, when switching to a larger gear the bike becomes easier to peddle, at the expense of top speed. It works the same way in the car, going to a numerically higher gear will move you quicker and get you into the powerband quicker, while sacrificing some top end.

[M1 Stang 04]

so overall, which is the best balanced gear for acceleration and top end? something in the middle. btw, what do our cars come with stock?

[Chaucer]

3.55's