Rear Diff Crush Sleeve

[JayArr]

Hi All

While under the Envoy yesterday doing u-joints I noticed the seal on the pinion yoke has started to leak. I topped up the gear oil but this will need to be replaced before winter.

I was looking for crush sleeves on ROck Auto and got somewhat confused. Take a look at how they list them, I've got RPO codes GU6 and G80 so mine is a limited slip 8" 3.42:1

GM GENUINE 09785792 Info

Fits Rear; Rear; Envoy Base Model; .058-.071'" Thick; 4.10 Rear Axle Ratio (GT5)
or Rear; Rear; Envoy Base Model; .058-.071'" Thick; 3.42 Ratio (GU6)
or Rear; Rear; Envoy Base Model; .058-.071'" Thick; 3.73 Rear Axle Ratio (GT4), Positraction Limited-Slip Rear Axle (G80); 4 Speed Automatic Trans.
or Rear; Rear; Envoy Base Model; Exc. Positraction Limited-Slip Rear Axle (G80), Limited Slip Differential (G86); .058-.071'" Thick; 3.73 Rear Axle Ratio (GT4); 4 Speed Automatic Trans.

Line one says it fits the GT5, Can I read that to mean with or without G80?

Line 2 says it fits the GU6, Can I read that to mean with or without G80?

Line 3 says it fits the GT4 with G80

Line 4 says it fits the GT4 except with G80

Anyone got a part number for for the crush sleeve on an 8" 3.42:1 LSD?

 

[Reprise]

Crosschecking against some GM online parts sources, that appears to be a common part for several differentials between 1984-2015 (even for the 7.25" front diff).

For the TB, it lists it for all 3 engines, w/o regard to diff size / gearing.

I think you're safe with that part. Let's see if anyone agrees with me.

 

[Mooseman]

G80 or not, the rings and pinions are the same so the crush sleeve is the same.

 

[JayArr]

OK, ordered, along with all three seals and a fixture plate to hold the yoke.

Side note: There's a dimple at the very bottom of the diff case about the size of a drain plug hole, (like they considered it and then decided to save 10 cents).

Anyone ever drilled and tapped it to give themselves a way to drain the diff without pulling the cover?

Anyone know the tap size for those drain plugs? (National Coarse or pipe thread?)

 

[JayArr]

Found it.

Ordered 5 drain plugs, a 1/2"-14 NPT tap and a 45/64 stepped drill bit from Amazon.

 

[Mooseman]

2002 had the drain plug there and, as you guessed, decided to save 23 cents and deleted it from later years. It's nice but you don't get to inspect the internals and the magnet, which you should add one to the plug.