Rear diff fluid

[Dantheman1540]

I pulled apart the carrier from my new 14b that had the markings on the spider gears. Heres some pics, they look like it could be shock load stress like @Rocket Man suggested.

Also glad I didn't plan on running these

 

[wjburken]

I pulled apart the carrier from my new 14b that had the markings on the spider gears. Heres some pics, they look like it could be shock load stress like @Rocket Man suggested.

Also glad I didn't plan on running these
View attachment 254939 View attachment 254940

Ouch. Bad juju with those.

 

[Dantheman1540]

I definitely don't think they would have liked any 600hp clutch dumps

 

[Rocket Man]

I pulled apart the carrier from my new 14b that had the markings on the spider gears. Heres some pics, they look like it could be shock load stress like @Rocket Man suggested.

Also glad I didn't plan on running these
View attachment 254939 View attachment 254940

I wonder if that could be from using the wrong fluid like that article suggested. Seems possible I guess.

 

[Dantheman1540]

I wonder if that could be from using the wrong fluid like that article suggested. Seems possible I guess.

I'd say very possible. Truck was a WT model and judging by the etching on the pinion someone had tampered with it. When I cracked the cover the fluid was really gross, lots of sludge and the magnet was extremely fuzzy. Nothing big enough to feel just fuzzy mush.

I wouldn't be surprised if some jack wagon grabbed whatever was on the shelf.

 

[roc1967]

It bothers me that GM specs different fluids for front and rear diffs. Is there any harm in using the rear diff fluid (SAE 75W-90 Synthetic - GM PN 12378261) on the front diff, originally spec'ing SAE 80W-90 (GM PN 1052271)?

 

[Rocket Man]

It bothers me that GM specs different fluids for front and rear diffs. Is there any harm in using the rear diff fluid (SAE 75W-90 Synthetic - GM PN 12378261) on the front diff, originally spec'ing SAE 80W-90 (GM PN 1052271)?

There’s a reason they call for different fluids. I’m pretty sure you’d be more bothered if your front diff wore out from using the wrong stuff.

 

[Tiredmechanic23]

If I’m not mistaken, the G80’s do not need the friction modifier additive.

@Rocket Man or @Jolly Roger, either of you want to share what you learned about additives on the G80 differentials since you both went down the rabbit hole on this one recently?

Good to know. So no change from the older G80s in the 90s trucks. Ill be changing fluids this weekend then. Appreciate it.

 

[JonnyTahoe]

for some that may be. I take suggestions and research from there. Ive always gone about things that way. Take suggestions and further research from there.

Big question I have now as things have changed since my last GM truck/SUV. Do the G80 on the K2 platform require LSD additives or no?

You mean Limited Slip additive.

 

[bigdog9191999]

those good for welding up a unit! otherwise good for scrap.