Pretty soon the LS will be burning both rear tires
LSD out of a 2004 Mustang GT with 28K on it.



Sully, you know a LOT more about this than me. I don't have access to a lift, so up on jack stands it's going. Hopefully this weekend. I shouldn't need any other parts, right? What you see is what I got in the mail. Not in the pic is the pinion shaft and lock bolt. The bearings look to be in good condition, so I'm just going to re-use these.

Cool, you just putting a spool in or changing gears also?

No gear change... yet. That would require an 8.8" (instead of the 8.0" in there now), custom bracing for the bigger pumpkin, and a custom driveshaft. This is just a simple swap. There is another LS owner running 4.10's. Once this is my second vehicle, then I'll start doing some bigger and better upgrades. I can't have it out of commission for more than a few hours right now.

Well, I'm going to re-use the shims, so I don't think I'll need a dial indicator. But I did just order new ring gear bolts. Thanks for the suggestions!

I'm putting it in next week. Everything in northern MN comes to a halt right now. Deer hunting season

I agree with Joe.. you can't just 'swap carriers'.. The entire deal needs to be reset with shims and a dial indicator.

Well you CAN, but expect howling racket in a few hundred miles, followed by breakage.

Glad I'm having someone else do it for me. Those were his recommendations. He said bearings and shims should be fine. Both carriers are EXACTLY the same dimensions. I've never torn down a diff before, so my job is to hand the tools, watch, and learn. He told me we could re-use the shims. With a modification to something this important, I'm going to leave it to someone who's done it before. So sorry if my posts come off as being ignorant of the process, but I am ignorant in that area since I've simply never seen it or been taught. After the swap I'm sure I will understand better what it takes.

It's not that you can't reuse shims.. but you may need to add or subtract.

*every* rear gear carrier needs to be reset for a gear change. Just because they spec the same on paper doesn't mean they do in reality.

I have an email in to the guy who did this exact mod before. He was the one who informed me it was the exact same size. I was taking his word for it since he has seen it in person and performed the work himself. I'll see what he says. Maybe I'm misinterpreting something.

I'd like to add that I'm not trying to offend anyone here. These were just new suggestions other than what I previously heard, so now I'm second guessing what I need to do. I just want to make sure I'm relaying everything to you guys properly.

Pete......

Let me clear things up. Rob was right when he said they are the same size. What was left out in that info is that in ANY change of rear end type work, you need to be 110% sure that everything lines up perfect! Thats why everyone harps on not doing it alone for your first time. What everyone here is saying is that a one inch part could be .9999 or it could be 1.0001 Its the tolerance game. That little bit of difference is where you need to make sure the shims are going to hold it in the correct spot. You might get lucky and be able to reuse/resize the shims that are in there, but you are better off time and money (and its just fucking easier) to have a new set of shims and start fresh.


Glad to see you putting the power to both wheels........ now you just need to make more power

That's who I emailed. He pretty much said that there is a good chance I won't have to re-shim. OF course, We'd check everything before re-assembly, to make sure. Then we'd re-shim if we need to.

So, I guess my next question is, how does one go about getting a set of shims without knowing how much one may have to shim? Do you just buy a universal set with different sizes or what?

Thanks again everyone for all the help

Oh, and Sully, I don't know how much money I'm going to throw at the LS. I'm still debating whether or not I want to go the FI route. Did you see the SC kits are now available?

SC kits? ehhhhh turbo > sc in my book!


20-25hp per lb of boost vs 10-15..... yeah I'll take the turbo anyday of the week!

yea like they've all said. i did a posi conversion on my nova and when i swapped carriers the backlash was alittle over 12 thou. i brought it down to 8. it was all the same parts but 4 thou aint much. goood luck and hope it all works out. you can probably get shims at most parts stores