My 86 Z28's 10 bolt rear end is starting whine...... it also is only a one legger with 3.23 gears. So i started looking at posi units and new gears for the 10 bolt and if i were to rebuilt my 10 bolt rear end i would be looking at about 600 bucks give or take... $430 for posi, $180 for gears, and i would be doing all the labor. Now one of my buddies works at a chevy dealership and he got his hands on a 2000 Ws6 trans am rear end, it was in the shop for a broken pinion gear.(the car had aftermarket 4.10 gears) So the dealership wanted to play it safe and get a whole new rear end for the car. The rear end has the calipers, rotors, and posi unit still in it all i would have to do is buy gears and a proportioning valve. He is asking 500 bucks for it... or he says he will take my 92 rims and 200 bucks... what do you guys think i should do? is it worth 500 bucks... i mean i like the idea of having 4 wheel disk brakes, posi, and some nice 4:10 gears.

 

i forgot to mention this will be going behind my 406 small block (350-380 HP), and a world class t-5... planning on a t56 in the future that is why i am going with 4.10 gears.

 

Well, you already know the rear broke once right? Then why buy it? 10 bolts are notorious for flexing, which usually causes the ring gear to break off teeth. The rear could already be messed up. Thats why they didnt reuse it

You can find quite a few LS1 10 bolts with all sorts of gear setups (including 4.10) for sale over at www.ls1.com for comparable prices. In fact there are 2 for sale right now!

A warning too. With 4.10 gears the chance of that rear breaking dramatically increases. Those 4.10 pinions are quite small. And that to the increased mechanical torque from the higher ratio, and the fact you've got a 406, AND you've got a manual. That's a recipe for disaster.

 

yeah i know it broke once... i dont like that but it would be sooo much cheaper than rebuilding my 10 bolt. Say i were to use like a 3.73 gear would that make it any less likely to brake? i was planning on getting a set of richmond gears and putting in new axle seals and everything while it is apart..... so it would pretty much be a brand new Ws6 rear end... i would be re using the posi unit with new gears.... but i understand what you are saying... i dont know i guess ill have to price everything out

 

I put a 2001 SS rearend in a '90 IROC, the 4th gen rearend is 13/4" wider than the 3rd gen rearend. The finished product looked ok but you could tell it was wider. Everything bolts up exactly like it should with the exception of the E brake. Being the 4th gen rearend wider you stock E brake cables will not fit without modification.

 

You can get entire 4th gen rear axle assemblies from lots of places (like www.speedautomotive.com) for $250-300 complete. The one you refer to is only worth maybe $100 IMO......

While I agree with all of the comments above about the weaknesses of the 10 bolt, it is really a very economical option for most of us. However, with your 406/manual trans setup, I would have to strongly suggest you save your money for a 9 inch or a 12 bolt if you have any thoughts of drag racing it or even putting sticky tires on it and street racing it.

Oh, and the 4th gen axle is 3" wider from axle flange to axle flange so your wheels will stick out 1.5" farther on each side with a 4th gen rear axle and 3rd gen offset wheels. You can remedy this (as I did) by going with 4th gen offset wheels in the back. I also have the same size wheels in the front with billet spacers from SPD to move the mounting surface of the front out to where the 4th gen spec wheels need it to be.

 

Dude you never called me back yo! I'm gonna be at my womans again this weekend...We should get together...

 

hey klayburn... me and my girl are thinking about going down to mansfield or strongsville to go shopping this weekend.. let me know what your doing and where your going to be.

 

Ok, ill get with my girl and find out whats going on...