Ok I give up. My dad has a 03 silverado 4.8 auto 4x4 ecsb. Its got an open rear out back w/ 3.73s. He would like to make it a posi or locker for better snow and dry traction. So far, nothing has worked.

Right now, we have tried those drop in lockers but they dont fit. We tried the powertrax no slip setup (have one in another car and it works great and install was easy) but we've yet to find one that fits. First, we were told it was a 8.5 30 spline....doesnt fit. Sent it back got the 8.6 30 spline, doesnt fit. We then tried a Detroit TrueLock and were told a 8.5 30 spline would fit...and no. None of them pysically fit in the carrier once I remove the side and spider gears.

So what gives? What rear end is in this truck? Did GM change the rear they used in 04...I'm thinking if this truck was built late enough, we may have gotten one w/ a 04 rear.

Any ideas? He will even go as far as ordering an Auburn or Eaton but who knows if we will even get the right one.

Thanks
Nick
'88 SS 357

 

auburn

 

EATON....auburns suck....Blew up a pro series about 3 months after it was installed. The eaton has seem some 4000 rpm launches on slicks with NO trouble at all. The auburn broke driving home from work ( read: no abuse).

 

go to the dealer and have them run your vin in theyre vis that will tell you what rear you have better yet pm me your vin and ill tell ya tommorrow and i might even get you gm part numbers for the eaton style!!

 

Cool I'll get the VIN tonight for ya so you can have it for tuesday...

I had the dealer run my vin before and all they knew was it had 3.73s. They looked at me like i had an extra arm when I asked what rear end was in the truck.

Thanks
Nick