2008 Mustang GT 500 rear gears

bbfmavrick · 05-17-2008

Hey Guys, A friend of mine needs some input. He is known in these parts as the reargear guru BUT, he's not beyond asking for help when he gets stumped. He installed a new Ford 3.73 ring/pinion in his new GT 500. They will not stay together longer than the time it takes to try the car out.

Are these 8.8's set up any diff than the old 8.8's? Has anyone else had any problems? Thanks Rick

**stlwagon** · 05-17-2008

No difference. Sounds like a bad install.

hotshot · 06-02-2008

the GT500KR comes with 3.73's and so does the Bullitt. Do they both use the same rear end?

**stlwagon** · 06-03-2008

Quote:

Originally Posted by hotshot

the GT500KR comes with 3.73's and so does the Bullitt. Do they both use the same rear end?

They're both 8.8".

GT500Girl · 06-03-2008

It sounds like a bad install to me. We have done my gears 3 times now..changing to see what would be best for my application and I ended up with 3.73's in the end. You have to switch some of the shims. He can call my hubby if he likes..just PM me and I'll send you the number. The GT500 has a different pinion bearing and race than the GT but they are all the same 8.8 as far as I know. You can NOT get the replacement bearing. Not even from the manufacturer. Trust me..we own a performance shop and I have contacts in Ford and the manager of SVT engineering. They don't plan on ever selling it. They DON'T want us running bigger gears. The KR and Bullitt have the 3.73's so you could get a complete axle assembly WHEN they put them out for sale. They will not sell them yet..I've tried and keep trying weekly. Of course you can get the GT500 complete assembly but it will be 331's.

Alot of guys are using the GT pinion bearing..but I have no idea how the heck they are getting it to work when it's different in the GT500

PLstang · 06-04-2008

Quote:

Originally Posted by GT500Girl

It sounds like a bad install to me. We have done my gears 3 times now..changing to see what would be best for my application and I ended up with 3.73's in the end. You have to switch some of the shims. He can call my hubby if he likes..just PM me and I'll send you the number. The GT500 has a different pinion bearing and race than the GT but they are all the same 8.8 as far as I know. You can NOT get the replacement bearing. Not even from the manufacturer. Trust me..we own a performance shop and I have contacts in Ford and the manager of SVT engineering. They don't plan on ever selling it. They DON'T want us running bigger gears. The KR and Bullitt have the 3.73's so you could get a complete axle assembly WHEN they put them out for sale. They will not sell them yet..I've tried and keep trying weekly. Of course you can get the GT500 complete assembly but it will be 331's.

Alot of guys are using the GT pinion bearing..but I have no idea how the heck they are getting it to work when it's different in the GT500

That's good to know! I just bought a GT500 rear end from a wrecked car as mine has seen some abuse and we were planning on installing it later this month. i'll need to check on the pinion!

Doug · 06-05-2008

PLstang

Please check your PM.

GT500Girl · 06-05-2008

Quote:

Originally Posted by PLstang

That's good to know! I just bought a GT500 rear end from a wrecked car as mine has seen some abuse and we were planning on installing it later this month. i'll need to check on the pinion!

LOL mine see's tons of abuse. We'll just say I drive it like I stole it. lol Yeh...that would be awsome to have a extra pinion and race.

GT500Girl · 06-05-2008

Quote:

Originally Posted by Doug

PLstang

Please check your PM.

Hey Doug. I don't see any new PM's. I'll try to send you one.

sorry..you weren't talking to me. lol