I have an 01 ss a4 3200 stall stg 2.5 ls6 heads tsp .595 .603 fast 92/92 and a bunch of bolt ons aaaaaaand I broke my diff im looking to replace my broken stock diff with a Detroit locker with 3.73s? the car is my DD I was just wondering if it would hold my power and drive good the car but down 440 at the wheels then 2 days later broke the diff. specs on the Detroit locker or suggested diffs would be nice thanks guys!



ps. I don't have money for a 12 bolt or a new rear end oh and I drag the car maybe once a month on mt et streets and street race A LOT

 

Start saving for a real rear end if you race it as often as you say.

 

So you want to put a locker in the stock 10 bolts, that is your daily driver and you street race a lot with drag radials on the back? That all together just sounds like a terrible idea.
Like stated above you better just buy a good 9" or a 12 bolt.

 

You have a few options:

-Keep replacing the 10-Bolt and blowing it

-Save some money up and buy a 9"

Yea, it might take a while to save up some cash, but if you keep putting stock junk in it you'll be wasting your time/money. Seems like you do a lot of racing, you're going to need something that will take the constant abuse.

 

dammit lol anyone got a used 9" or 12 bolt

 

My ride came with a Detroit Trutrak on the stock 10 bolt, and is still holding at about 550 rwhp with 4.10 gears and a 6-speed. When I get the money i'm going straight to the 9" rear lol

 

If you are around 400 rwhp not running the track all the time etc. read this as it is true. Source of this has been around along time and works with differentials and rears all the time.Several sources also state the same. Look up Gm high performance on the write up if you would like. You will hear guys stating do not waste your $ go with an aftermarket rear. If you plan on not going over the max rwhp stated above and are not dumping a clutch at 5 grand with 600 rwhp this will be a good fit for you. Now if you plan on going over the max rwhp and dragging all the time go for the 9 or 12 bolt rear.

We all are painfully aware of the Achilles heel all 82-02 F-bodies share, the 7.5? and 7.625? Corporate 10-bolt rear end. What makes these rears so weak? Essentially, it?s the size of the ring gear. At 7.5? it is simply too small to support high torque loads or severe shocks. With most F-bodies weighing in around 3600 lbs, the situation is even worse as the loads on the gears are increased as the engine tries to overcome the inertia of the car sitting still. In a 2900 lb Fox-bodied Mustang, the 10-bolt would probably be at least somewhat more durable.

Generally, if you are racing an automatic, you?re going to be safe on the stock 10 bolt well into the low 12 second ET range. Once you hit 11s you may want to start saving up for a rear because a catastrophic failure is now only a matter of time.

There are measures you can take to upgrade and strengthen the 10-bolt. None of these measures will enable it to survive behind an M6 car with Drag radials or slicks, but for Autos into the 11s and stick cars on street tires in the high 12s you can get by with an upgraded 10-bolt with the following modifications:
• Weld the axle tubes to the differential housing. OEM uses only two small spot welds
• Moser or other aftermarket axles, these are as much as 30% stronger than the stock axles and will reduce the chance of sheering off the splines or snapping an axle in two
• T/A or other brand performance rear end girdle cover. The preload caps on the cover help hold the differential bearing caps in place to prevent heavy torque loads from throwing the casing and gears out of alignment.
• Main bearing stud kit?replacing the stock bolts further increases bearing cap stability.
• Solid pinion spacer aka Crush Sleeve eliminator. Another method of death for the 10 bolt is when, due to high load, the crush sleeve, which is used to set pinion depth, collapses and allows the pinion gear to walk up the ring gear. This misaligns the teeth and then the gears pretty much eat themselves. The Solid spacer takes the slack out of the setup and will not allow the pinion to move backwards into the ring gear.
These upgrades should allow you to reliable hold 350rwhp in an M6 car on street tires and up to 400rwhp in an automatic with any tires and a higher stall converter. The high stall speeds actually soften the shock to the gears.

However, even with these upgrades, the ring gear can only be so strong due to its size. It is recommended you use the highest quality gear set you can find, which means Strange/US Gear or Motive. Also, stay away from 4.10 or higher ratios. The higher ratios require more ring gear teeth, meaning they have to be narrower and therefore more brittle. For best 10-bolt life I?d recommend going no higher than 3.73s.