[MATT02GT]

So Ive got some bearing noise coming from the rear end But anyways if Im gunna tear into it, its getting upgraded. Im putting over 400hp the the wheels and plan on more in the future so Im wanting to build something bullet proof without breaking the bank. I want to up grade to a 31 spline setup with a diff that lets me drive it on the street but also will take some punishment at the track. So im just looking for some different combos/ideas you guys might be running. I want to keep it in the $400-500 range and I plan on reusing my 3:73 gears and also welding the axle tubes while I'm in there. Any input would be great, thanks.

[Black Bullitt]

I bought my cobra diff, diff cover, and 3.73 gears from Ford Racing Parts and Accessories at great prices 31 spline moser axles from AM. I think I spent just under 1k or a complete built rear end.

[ITS ME DAVID]

ow man rwhp can that rearend handle..

[Black Bullitt]

I'm not sure, but it's holding just fine on my DRs with 2400 launches.

[ajm]

With a budget of 450-500 id do this if youre set on a 31 spline setup

used 31 spline diff from the junk yard or similar, then rebuild it with the carbon clutches and replace the bearings. Prolly cost you $150-175 total. Or buy one for about $240

31 spline axles - $275 or so

and personally if at all possible id throw on a rear griddle and stud kit for the bearing caps.

that should make it quite healthy.

[MATT02GT]

I did plan on the rear end girdle also outside the budget. I found a used 31 spline auburn diff for 200 bucks so I might look into that. How hard is it to rebuild a diff? Im pretty mechanicly inclined, just never had a chance to play with a diff. Also where would I find a 31 spline diff in the junkyard, Explorers and F series trrucks?

[Hot66Rod]

are you sure its a bearing noise you got...i thought it was in mine and rebuilt the whole rearend and i shouldn't have cause the guys that done mine fucked up the gears and it still didn't stop the noise and now my gears whine...but i found out what the noise was and it was the brake caliper...it was locking up...just a thought...and you can buy a cobra diff off ebay really cheap...i bought mine for 60 bucks and bought some used mosser axels for 120 and bout gears for 150...then paid a guy to put the gears in for 300 and they messed up the gears...the install kit cost 80 bucks...so now i got to get new gears again...lol

[ajm]

Originally Posted by MATT02GT I did plan on the rear end girdle also outside the budget. I found a used 31 spline auburn diff for 200 bucks so I might look into that. How hard is it to rebuild a diff? Im pretty mechanicly inclined, just never had a chance to play with a diff. Also where would I find a 31 spline diff in the junkyard, Explorers and F series trrucks?

Yea explorers,expeditions, f150s, etc can have the 31 spline diff. As for rebuilding one its pretty simple. Pop out the s spring, remove the spider gears, remove the clutches, soak the new clutches in friction modifier then stack them in order/per the directions, reinstall the spider gears, reinstall the s spring and youre good to go.

200 bucks for the auburn sounds like a good deal

[RyanGT]

Yeah what i did was got a brand new cobra 31 spline for like 150 bucks or something. Then the install kit. Reused my gears. New 31 spline axles, and a differential cover (another 100 bucks). If it is a good shop reuse the gears and you should be fine. If not they will whine probably. My gears didn't have that many miles on them.

[MATT02GT]

Ford Racing 8.8" 31 Spline Traction - LOK Limited Slip Differential at AmericanMuscle.com - Free Shipping!
Ford Racing 8.8 in 31 Spline Traction - LOK Limited Slip Differential w/ Carbon Discs at AmericanMuscle.com - Free Shipping!

I found these on am....seem pretty cheap. Any idea why the carbon disc diff is cheaper, I thought this would be the stronger one?

Moser 31 Spline Mustang Axles for 8.8in Rear w/ Studs (99-04 GT, Bullitt, & Mach 1) at AmericanMuscle.com - Free Shipping!

Also the axles are on sale, doesnt seem like a bad setup and itd put me pretty close to my budget

Does the MM discount code work on sale prices? If anyone could could pm the discount code that would be awesome.

[RyanGT]

Do the axles have the abs thing on it? Something to double check.

[RyanGT]

Its on sale more 28% compared to 10%. And you can find those differentials for cheaper im pretty sure. Same one i got for 150 somewhere.

[ajm]

Sounds like a good setup. Dont forget to set about 50 aside for some good fluid and black rtv. Youll need 2 quarts 4 oz of fluid...so 3 quarts which will run you 10-15 a quart. Or if youre really tight on money get 2 quarts of fluid that does not have friction modifier in it and 4 oz of friction modifier and youll be good to go.

If that is pushing you close to your budget check latemodelrestoration.com the axles are about $5-10 less, the diff with carbon is about $15 less, and the diff w/ regular is about $50 less. Always funny how everyone is swingin on americanmuscle but half the time their prices are higher.

[RyanGT]

First thing on search. Buy Ford Racing Parts - 8.8 inch 31 Spline Traction-Lok Differential

[RyanGT]

Yeah, although free shipping! Some stuff they have good prices on, others (like this) you can find elsewhere.

[RyanGT]

Speed Concepts - M-4204-F318C - Ford Racing V8 T-Lock for 1979-2008 8.8 31 Spline Mustang GT/Bullitt/Mach1/Cobra/GT500 (with carbon fiber clutches) one for 209 (the website i got mine for 150), but they sold out of those. Hell i had to wait like 4 months on backorder for mine.

[MATT02GT]

I guess I got some more looking around to do lol

[Black Bullitt]

Originally Posted by ajm Sounds like a good setup. Dont forget to set about 50 aside for some good fluid and black rtv. Youll need 2 quarts 4 oz of fluid...so 3 quarts which will run you 10-15 a quart. Or if youre really tight on money get 2 quarts of fluid that does not have friction modifier in it and 4 oz of friction modifier and youll be good to go. If that is pushing you close to your budget check latemodelrestoration.com the axles are about $5-10 less, the diff with carbon is about $15 less, and the diff w/ regular is about $50 less. Always funny how everyone is swingin on americanmuscle but half the time their prices are higher.

True, but then you have to figure in the shipping, because it's not always free on every other performance website.

[ajm]

Really???? I thought everyone had free shipping?

lets see here. He buys axles and either diff from lmr. He saves 25-65, pays 15 to ship, and still saves 10-50 in the end. Yes you have a point. But even if you do have to pay shipping else where depending on the situation it still may be cheaper in the end.

[RyanGT]

Yeah shop around. I always check like 10 sites before i dial down and get what i was going for. LMR is a good one. I usually get stuff from there. And shipping isn't that ridiculous for parts as you would think, they get good discounts. If we shipped same item it would cost 4x more.