SWEET98SS

iTrader: (8)

So I finally got some tires that grip, Nitto 555r's. I have had them for about 3 weeks and now I am hearing some noise in the rear, kinda like clunking.

I need to know, when I spin one wheel, isnt the other one supposed to turn? I have pulled the whole rear apart, gears look brand new, 3.42 stock from GM, 95,000 miles. I am leaning towards the Posi making all the noise.

If it is the posi, what does everyone recommend? I am leaning towards the auburn.

FirstYrLS1Z

iTrader: (4)

99 would have a torsen 'posi',they act differently when spinning the tires with the car off the ground. If when you pulled it apart and there were no metal parts in the fluid,it's still relatively intact. Torsens do become 'clunky' with age as they're a 'catch up' differential in regards to one wheel vs the other wheel.

SWEET98SS

iTrader: (8)

There was no material in the fluid. Is it worth it to fix this rear or go with a 12 bolt. I would hate to put the new posi($500) in it and then it breaks again. I priced out a S60, with a driveshaft its $3000.

FirstYrLS1Z

iTrader: (4)

sticky tires with an M6 will break 7 1/2-7 5/8 rearends. 12 bolt minimum to use.
The spiders in an Auburn wouldn't last either.

SWEET98SS

iTrader: (8)

Thanks for the info. I just find it hard to drop that much cash for a rear, but then again, I dont want to break in a week and be out $500.

FirstYrLS1Z

iTrader: (4)

this 'gears and axle' section has a lot of threads with similar situation.

saluki

If it was a 10 bolt, junk it...

We've rebuilt the 10 bolt in our STOCK '02 silverado 4 times. Now while pulling a 3500 pound car isn't the best thing to do, It shouldn't break it repeatedly. now the trans and motor are a different story. they are about to hit 250k miles. It would be a bit understandable if one of them said bye...

SWEET98SS

iTrader: (8)

I found my issue, the bolts that came loose on the top of the posi allowed the gear in the diff to come up too high, it chewed some teeth off and cracked the housing.

I am going to buy a new differential any suggestions?

silent_soul

iTrader: (2)

ive been looking at buying a new rear, I have a m6 car and everything ive seen says 9" or eventually youll probably spend more still.

as far as which 9"

I have read the fabs are nice, the none fab work fine and if its 600+ HP get the back brace or a fab, again this is stuff ive read and I havent bought anything yet.

still researching but everything always says 9" if keeping it a m6 car.

saluki

If you guys do go with the 9" I suggest Burkhart Chassis

SWEET98SS

iTrader: (8)

Here are the pictures of the damage. Its hard to see but there are cracks in the casting on the top cover of the differential. Also, if you look close, you can see a tooth missing on gears inside the diff. The ring and pinion gear look like new for 95,000 miles.

FirstYrLS1Z

iTrader: (4)

https://ls1tech.com/forums/gears-axl...c-failure.html

SWEET98SS

iTrader: (8)

So is it worth it to put a new posi in this rear or buy a used one? I found one for $165 shipped, 85,000 miles. Im not ready at this time to dish out $3000 for a new rear and driveshaft.

silent_soul

iTrader: (2)

Your in a tighter spot than me for sure as my rear is possibly only making alittle noise.

However I have priced parts for a killer rear build into the 2200 range and thats for a bulletproof overkill setup assuming I assemble and what not.

I have access to the mwr auto hobby shop though so I have cheap and easy access to a pro garage with every tool needed. If you can build yourself you could probably make a very usuable 9" fall into the 1500-1700 range if you use some junk yard or used parts but its up to you and your comfort level too.

when i say junkyard I mean for center section to get you by for a while. I assume your buying a prefab'd fbody 9" rear

N20zuki

The stock one in a F-body is a 7.5in 10bolt... The stock one in a Silverado 1500 is a 8.5in 10bolt... They are nothing alike, Other then the fact they are a rear axle, and both use 10bolts to attach the diff cover...

To the OP its either time to bandaid the stock rear fixing it or step up and get something bigger and better.

SWEET98SS

iTrader: (8)

So I had the choice of buying a used, new or go S60. So $165, $400 or $3000, of course I chose the cheapest being this is a 10 bolt.

Now if my gears were messed up or broke off I would definetely go S60 but being how this was caused by loosening bolts, I chose just to go the cheap route.

So far I have $175 in parts, including the differential picture below, oil, additive and new axle seals. Not too shabby. Now lets see how long it lasts

saluki

whoops... whoever put up on wikipedia they are the same is an idiot then, and I'm an idiot for believing them.

Since you went the Bandaid route this time I suggest next mod should be a rear end.

01ssreda4

iTrader: (96)

It'll hold for a while. Have fun.

SWEET98SS

iTrader: (8)

Yeah, im not a bandaid kinda guy but im not in A position ro drop 3k right now so this will do.

Bob@BruteSpeed

iTrader: (16)

I agree, see the info I have at the link here. http://shop.brutespeed.com/Brute-Spe...nformation.htm Bob