Thread: simple differential question

Some of you know that I fried my diff. So I'm getting one from the jy. My question is can I take any differential from any hd trans? I found two +04 grand prixs that have the gen v. so there fore they have hd trannys. Will they work? Mine has 34 teeth so it's 3.29?

I have swapped a diff from a regal to a GP, they were exactly the same minus the speed sensor connection was different. so my guess would be as long as you find a HD tranny with the correct gears, it should fit. just keep your VSS handy

So if the sun gear has 34 teeth and the other side has 30 than I'm good...? What is vss?

Originally Posted by m17davis

What is vss?

Vehicle Speed Sensor

Sweet. Thanks. Do you guys have any easier methods of removing the passanger axel?

Unbolt stuff and either yank it out or get a pry bar in there and 1 swift move and it'll pop right out.

yup, big pry bar and a swift motion

All HD diffs are 3.29 in a 4T65 trans. Make sure you put the sun gear in the correct way and you'll be good.

ATSG manual says to put a big screwdriver or wedge in there and give it a whack... it's all good as long as it's a fast hit to make the compression ring compress.

Originally Posted by BillBoost37

All HD diffs are 3.29 in a 4T65 trans. Make sure you put the sun gear in the correct way and you'll be good.

ATSG manual says to put a big screwdriver or wedge in there and give it a whack... it's all good as long as it's a fast hit to make the compression ring compress.

Not saying youre wrong, but arent the GTP's and GXP's HD diff's? which are also 2.93

HD's are all 3.29 diffs. The 2.93 is created by using a 33/37 drive/driven gear/chain setup at the other end of the trans with a 3.29 ratio diff. When you divide 3.29 ratio by the chainset 1.12 you get 2.93.

GM calls the diff the final drive which I originally found confusing. I was thinking final drive ratio was the overall ratio. It isn't.

Originally Posted by BillBoost37

HD's are all 3.29 diffs. The 2.93 is created by using a 33/37 drive/driven gear/chain setup at the other end of the trans with a 3.29 ratio diff. When you divide 3.29 ratio by the chainset 1.12 you get 2.93.

GM calls the diff the final drive which I originally found confusing. I was thinking final drive ratio was the overall ratio. It isn't.

and I apologize for thinking you were wrong. fwd trannys always confused me with the layout, rwd just makes more sense to me and I have 100x more experience with rwd