so last summer I blew my 70 up on the drive up here. had the entire unit rebuilt by the most reputable shop in town. couple months later it started clunking, I took it in, they did a hub to hub rebuild of bearings and clutch pack.
That was november. I just went out and checked my fluids, and the 70 is black. Not 2 month old fluid, daily driving, no towing, no loads at all. The power lock is set as tight as it will go, so is it maybe clutch material? Shouldn't the fluid still be clear? I haven't even started paying off the original bill.

 

It will be fine gear lube is black by the time you get to the first stoplight from leanin the shop. As long as its not gritty or shinny i would say your good.

 

thanks garret. this is starting to make me nervous, I had the first power lock installed nov. 08, fluid looked nasty as heck for 3 changes, then I lost the whole rear, had it redone, it crapped out, rebuilt now it looks black again. I was starting to wonder if having the clutch shimmed tight leads to earlier failure.

 

i dissagree... my gearlube stays clean for years.

 

I have never had gear lube turn black

 

the only fluid in my trucks that is black is motor oil

 

Did they get the case and axle tubes cleaned out from before? Gear oil shouldn't turn color that fast.

 

I had a 12 bolt chevy rear in a truck I used to have. I went through 3 gear sets before I found out the housing was bent and it was eating them up. It put something in a bind and just wrecked it.

 

this is the same axle my dad towed his gn with regulary grosed out at 22kplus. he did this day in and out for 6 years until getting his 01 cummins. nothing has changed until I got the power lock installed. its like that was the killer. I cant afford this.

 

start asking junkyards about D80's .

 

I was going to suggest going to the D 80 i had a shop do mine .....
I cant weld worth a **** . Put some new shock perches and welded the New E brake cable mount on on and shortened the Drive shaft
If you need pictures i can send you some plus there is a thread on the forum about it too

 

this is what Im hoping. the fluid is just dark, the other times it would look like someone had dropped a handfull of sand in the case.