Rear Axle Question

[Harvey Halabookie]

I am looking to change the rear diff cover to an aluminum or chrome cover. Can anyone tell me which diff I have or how to find out (i.e. 10/12/14 bolt, Dana, ring gear size, etc.)?

 

Also, are they limited slip (like posi) or locking differentials?

 

Is there a way to tell through the RPO codes?

 

Thanks

[jeffbf89]

Don't know about the rest.

G80 Differential, locking, heavy-duty, rear

GT4 Rear axle, 3.73 ratio

GT5 Rear axle, 4.10 ratio

GU6 Rear axle, 3.42 ratio

[Ben]

Here's the link to Colorado K5's site with the diff profile pictures.

 

Colorado K5 diff profiles

[MS3DALE]

I am looking to change the rear diff cover to an aluminum or chrome cover. Can anyone tell me which diff I have or how to find out (i.e. 10/12/14 bolt, Dana, ring gear size, etc.)?

 

Also, are they limited slip (like posi) or locking differentials?

 

Is there a way to tell through the RPO codes?

 

Thanks

 

 

 

 

 

You have the 10 bolt 8.6 inch rear diff.

[Harvey Halabookie]

I am looking to change the rear diff cover to an aluminum or chrome cover. Can anyone tell me which diff I have or how to find out (i.e. 10/12/14 bolt, Dana, ring gear size, etc.)?

 

Also, are they limited slip (like posi) or locking differentials?

 

Is there a way to tell through the RPO codes?

 

Thanks

 

<{POST_SNAPBACK}>

 

 

 

You have the 10 bolt 8.6 inch rear diff.

 

<{POST_SNAPBACK}>

 

 

 

 

I never heard of an 8.6 inch rear. I've seen 8.5, 8.875, and 7.5 listed.

 

I'm looking at the TA Performance or LPW rearend cover/girdles they seel in Jegs or Summit Racing. I had one on my 8.5 inch 10-bolt in my old Malibu.

 

Can anyone be more specific as to what rear diff is in my truck and which covers (make/part number) fit? I have the G80 and GT4 RPO codes. Thanks.

[Ben]

Guess too much work to go to the K5 site.

 

Maybe this site easier: Diff bolt patter ID

 

Or especially lazy, how's about one of these pictures:

 

 

 

Or this site: Another diff profile ID site

 

 

Or this site: Another one

 

Or this site: Best one yet

 

[Harvey Halabookie]

Guess too much work to go to the K5 site.

 

Maybe this site easier: Diff bolt patter ID

 

Or especially lazy, how's about one of these pictures:

 

 

 

Or this site: Another diff profile ID site

 

 

Or this site: Another one

 

Or this site: Best one yet

 

 

<{POST_SNAPBACK}>

 

 

 

 

Thanks pal. The K5 site didn't really help, but the ones above did. I guess I do have the 8.5 ten bolt.

[bigdogs]

Too bad it is not up to date to cover the 11.5" GM rear end

[MS3DALE]

I am looking to change the rear diff cover to an aluminum or chrome cover. Can anyone tell me which diff I have or how to find out (i.e. 10/12/14 bolt, Dana, ring gear size, etc.)?

 

Also, are they limited slip (like posi) or locking differentials?

 

Is there a way to tell through the RPO codes?

 

Thanks

 

 

 

 

 

You have the 10 bolt 8.6 inch rear diff.

 

 

 

 

 

 

I never heard of an 8.6 inch rear. I've seen 8.5, 8.875, and 7.5 listed.

 

 

I'm looking at the TA Performance or LPW rearend cover/girdles they seel in Jegs or Summit Racing. I had one on my 8.5 inch 10-bolt in my old Malibu.

 

Can anyone be more specific as to what rear diff is in my truck and which covers (make/part number) fit? I have the G80 and GT4 RPO codes. Thanks.

 

 

 

 

 

 

Yep,When the new body style trucks came out in '99 GM upped the size of the rear from 8.5in. to 8.6in., actually in our parts catalog its listed as an 8.625 in. ring gear size,Most of the 8.5in. rear end parts will work in the 8.625in rear end.