Hey guys. I have a question as to whether any 04-08 8.8 rear end will fit an 04. My 3.73 posi went out. I can drive forward, but can't back up. I was able to locate an 07 and visually it looks the same but I want to try to make sure before I buy it. Thanks for any replys.

 

I believe all 04 + use a 9.75 rear end. The front is (I think) is a 8.8. I f you have an 04 NBS truck I think you are looking for a 9.75 rear.

 

it is new body style but 4.6 not the 5.4.

 

The 5.4 has a 9.75 rear diff. the 4.6 has an 8.8.
Losing reverse sounds more like a transmission issue to me.

 

If the rearend was bad it wouldnt move in any direction.

You need a tranny.

 

It's definitly the rear end as I had the dshaft disconnected and it locks up as soon(about 3/4 revolution) as you try to turn the hubs backwards. The very strange thing is ,I know its a posi,B6 Code + rearend tag, but turning the wheels by hand forward, 1 turns forward but the other turns back. If I lower 1 wheel to the ground only 1 will turn so it,s acting as an open diff. Ah well, I'll get it to a shop this weekend and we will figure it out. I think I was able to determine that all the 8.8 housings for 2004 thru 2008 are the same so if indeed its screwed up I can look for a low milage latter year unit. Thanks.

 

you mean you have 3.73 geared Limited Slip




try to find one with 4.10 gears