Where did you guys pick up your gears? GM wants big money for gears.


What are the differences between the gmt-900 1500 rear and 1990's gm 8.5 rear?


I tore mine apart to throw in some 4.10's I picked up from the junkyard from an early 90's 1500 10bolt. I thought it was a 8.5 ring gear just like ours, but ours is a 8.6?

At this point I understand its not the same according to the dealership and they want 550 for gears (09+ model and up listing)

I immediately noticed the bigger carrier bearings, and pinion bearing upon tearing my rear apart (compared to early 90's style). I kinda made the mistake and bolted my ring gear on to the differential without thinking twice and now it looks like I wasted some time and didn't do my homework.

 

Unless you have a good friend in the dealership, I wouldn't even bother calling them. For me, it has never not been a waste of time. You can get gears a lot of places...Ron's here on the site is a good place to get them.

 

PM Rons Machining services here on the site and they'll get you squared away. I get my gears thru him. I re-used my stock pinion bearings.
If you can't use what you have make sure you get a quality brand like Motives.

 

Someone else has posted here before the exact year, but it's my understanding that sometime in the late 90s the rear end went up in size to 8.625" and is now commonly referred to as 10-bolt, 8.6". The front diff is 8.5" if that info is required too.

 

the front is 8.25

 

we bought motive gears for our 2008 tahoe ,

the 8.6 is quit a good diff actualy but the problem is the g80 locker

it snaps so fast that it dameges the ring and pinion

 

So there was no rear changes from 09-10 or so? I just want to make sure becuase If thats the case any 99 and up should work?

I am used to slamming ford rears together with the original pinion shim/complete junkyard gears.

I'd rather just go back to the junkyard and try and find an "8.6" rear, even if it has only 3.42 gears it will save me bearing money. (because my autoparts guy already pulled the pinion shim off to put on my early 90's rear gears--but they won't work) and atleast I get an upgrade.

 

Why do most websites refer to gears they sell as 8.5/8.6?

 

Good question, but from my understanding, 8.5" ring gears will work in the 8.6" housing, meaning anything from 99-up should work.

 

First of all 550 for GM gears at the dealer is a ballin price. I know it doesn't sound like it but list price is about 850 and wholesale is around 570-580. That being said, yes Ron's machine is the bomb and does have awesome deals.

To the OP, If you bought gears for a 1990 1500 and another set for a 2010 from the dealership they would have the same part number on them. Your dealer is full-o-poo.