Hey,
I'm hoping some of you guys can share some of your wisdom with me.

I have a 2002 Z28 M6 w/ 4.10 gears. I know a bit about engine but the rear end is still kinda murky.

I know that it's a 10 bolt and everyone says it sucks and breaks and all. But what exactly breaks??? What's the difference between this and the 12 bolt.... 2 little bolts????

Can you strengthen it fairly cheap or need to buy a $2000 12 bolt for it???

Any advice or just a technical rundown would be greatly appreciated.

 

There are a variety of design features that make the "10-bolt" a fairly weak rear end. But ultimately, the problem is the small ring and pinion. The case is also not very strong and the bearing supports are kinda wimpy. A 12-bolt has a larger ring and pinion, stronger case, and a better design. A Ford 9" is even better in a variety of ways, including the even larger ring and pinion. 9" refers to the size of the ring gear.

If your car is basically stock and you run street tires, your rear should last. If you start modding the car and use sticky tires, it will not last long. M6 cars are notably toguher than automatics if drag raced. There is a lot of shock load when doing clutch dumps with stocky tires.

Rich Krause

 

Well then is there any way to strengthen my 10 bolt?? I have 4.10 gears in it.

Or am I just worrying about something I don't need to. Mine is a street car and I haven't taken it to a track yet. Won't be a regular track car.

Thanks.

 

I need to qualify my previous statement. When I re-read it I didin't want to make it seem like you were headed for an immediate rear end melt-down. Many people get decent longevity out of the 10-bolt in stock or mildly modded cars. But with sticky tires it's will eventually disintegrate.

Make it stronger? The cast aluminum covers with bearing supports are supposed to help, though I don't have any data to support their use. Use a good quality ring and pinnion. That's all I can think of.

Rich Krause

 

I read something about welding the axle tubes to the case, supposed to beef it up. You could also upgrade your axles, Moser makes some pretty tough ones. I'm redoing my rear next spring:

-Stock 142k 10-bolt
-TA Support Cover/Studs
-Motive gears
-Stock posi/axles
-I'm going to try the welding thing

Hopefully she'll stand up to the 450rwtq my 383 TPI will be putting down

-Rippin

 

Yeah, dumping the clutch or similar shock by an auto can remove some teeth from the ring gear, "done that"...Some older posi's spider gears self destruct..
You can:
Buy good hardened gears, break them in right!
Buy a solid pinion spacer, requires playing with pinion shims..
Buy the cast cover with set screws mentioned, keeps the bearing caps from distorting under extreme loads.
Buy aftermarket axles like Moser etc..
Weld the axle tubes on to the housing..
Use a "climbing" gear lube like Morroso or Lucas. but don't forget the limited slip additive!..

 

Great.... . I plan on taking mine to the track for the first time since I threw the motor in and I plan on using slicks. Do I have a lot to worry about being an auto and all with the mods below? What would you guys do? I just spend a sheeiiit load of money on all of this and can't afford no rear end right now.

 

S.J.S, I think I'd leave the line a little soft with all that hardware... I mean I'd stall it up, and then feather the throttle a little the first few feet, then plant it in the mat!... Or run some DR's and spin a few feet...
It's important to warm the rear up a little, so if you trailer it in, you might want to taxi around a little before making for pit row..
I made the mistake of being first in pit lane with a cold rear and freed 3 teeth from the ring gear...made an awful clunk,,clunk,,,clunk...sound!

 

I'm driving it down....that should warm it up enough (I hope). So you think if I nail her, I might break it?? That sucks man. I might just pass all together. But I gotta know how it does. Thats the only way I can consider this build a success.