OK, that didn't come out right! 🤔
I know that the front differential in my '04 TB EXT is the GM 7.25", but I'm confused about what the rear differential is. I had always assumed it was the 8.0, but then I read some posts elsewhere which said that the EXT's and 5.3V8's got the 8.6. My TB has the 4.2I6.
My wife has an '06 TB SWB. The rear diff cover on her truck was looking pretty ratty, so I got a new one from the dealer. Her rear diff is an 8.0. I decided to replace the cover on mine as well, so I bought another one. It fit perfectly, no leaks at all. It looked just like the one that was on there. I have come to find out that 8.6 was stamped onto the covers of those diffs. I do not recall that it had a fill plug in the cover, pretty sure it did not. I threw it away, so I don't have it for reference. My diff does have a fill plug on the right front, just as my the diff on the wife's does.
I'm at least the 3rd owner of this truck, so I don't know a lot about it's past history. I suppose it's possible that someone swapped out the 8.6, if that's what it originally had, with an 8.0.
I also read somewhere that the 8.6 has an additional reinforcement rib, but the poster didn't know where it was located. Does anyone know about this? The reason I'm asking is because I want to turn this TB into a bit more of a trail ready truck, and not just a mall cruiser. Not that I go to the mall very much anyway. There are more choices for locking differentials for the 8.6 than the 8.0, plus it's supposed to be stronger. Other than pulling an axle and counting the splines, does anyone know of a way to tell visually which diff is which?
Thanks, all!
I know that the front differential in my '04 TB EXT is the GM 7.25", but I'm confused about what the rear differential is. I had always assumed it was the 8.0, but then I read some posts elsewhere which said that the EXT's and 5.3V8's got the 8.6. My TB has the 4.2I6.
My wife has an '06 TB SWB. The rear diff cover on her truck was looking pretty ratty, so I got a new one from the dealer. Her rear diff is an 8.0. I decided to replace the cover on mine as well, so I bought another one. It fit perfectly, no leaks at all. It looked just like the one that was on there. I have come to find out that 8.6 was stamped onto the covers of those diffs. I do not recall that it had a fill plug in the cover, pretty sure it did not. I threw it away, so I don't have it for reference. My diff does have a fill plug on the right front, just as my the diff on the wife's does.
I'm at least the 3rd owner of this truck, so I don't know a lot about it's past history. I suppose it's possible that someone swapped out the 8.6, if that's what it originally had, with an 8.0.
I also read somewhere that the 8.6 has an additional reinforcement rib, but the poster didn't know where it was located. Does anyone know about this? The reason I'm asking is because I want to turn this TB into a bit more of a trail ready truck, and not just a mall cruiser. Not that I go to the mall very much anyway. There are more choices for locking differentials for the 8.6 than the 8.0, plus it's supposed to be stronger. Other than pulling an axle and counting the splines, does anyone know of a way to tell visually which diff is which?
Thanks, all!
