Check Your Rearend!

[crashz]

I had an interesting issue with my truck recently. I pulled into the driveway, behind my truck, and noticed that the differential cover was wet. I climbed underneath, and checked the fluid, and it was up to the plug. Hmm.

Noticed that the cover was wet on the bottom and around the gasket area. The pinion seal was dry as a bone. Not expecting much, I grabbed a cover bolt and was horrified to see that I could tighten it by hand, and at least a turn or two!

All of the bolts were loose to some degree. Not exactly sure why, but I assume that the cover gasket has shrunk a little. I serviced it this past summer, and torqued the bolts to spec. I routinely check the fluid level, and rarely need to add any. Never paid any attention to the cover bolts though.

So just a word of caution: Check your rearend!

 

[Diamondpilot]

I had an interesting issue with my truck recently. I pulled into the driveway, behind my truck, and noticed that the differential cover was wet. I climbed underneath, and checked the fluid, and it was up to the plug. Hmm.

Noticed that the cover was wet on the bottom and around the gasket area. The pinion seal was dry as a bone. Not expecting much, I grabbed a cover bolt and was horrified to see that I could tighten it by hand, and at least a turn or two!

All of the bolts were loose to some degree. Not exactly sure why, but I assume that the cover gasket has shrunk a little. I serviced it this past summer, and torqued the bolts to spec. I routinely check the fluid level, and rarely need to add any. Never paid any attention to the cover bolts though.

So just a word of caution: Check your rearend!

Never heard that one. Most modern truck have a drain plug so you do not need to remove the cover but my BIL's 06 F-150 does not on both the front or rear axle. We changed all the fluids this past Nov due to it having 120,000 miles and thought it was time. I will have him check them. I think he would notice though since he parks in the garage in the same spot and the same spot at work if it was dripping.

We torqued them also. I think 12# but can not remember now.

Chris

 

[PILOON]

Had a new, like 600 miles, GM product that emitted funny noise like driving on excavator indentations in pavement.
Caution directed me to pull over as this was not right!
As I hit the gravel ballest on road side the differential locked up suddenly.

The factory forgot to fill the differential! (must have been a Friday afternoon car) and that did not say much for dealer prep either.

 

[slowzuki]

Any chance you changed to a synthetic that attacked the gasket?

 

[clemsonfor]

Never heard that one. Most modern truck have a drain plug so you do not need to remove the cover but my BIL's 06 F-150 does not on both the front or rear axle. We changed all the fluids this past Nov due to it having 120,000 miles and thought it was time. I will have him check them. I think he would notice though since he parks in the garage in the same spot and the same spot at work if it was dripping.

We torqued them also. I think 12# but can not remember now.

Chris

Look at the guys avatar, if its the one in the picture its far from a modern truck! I have a 1980 K10 i check the diff several times a yr and just replaced the fluid this winter and put a new gasket on.

 

[crashz]

Believe it or not, the 1 ton rear is dry as a bone on the outside. Thats the one that I would expect to leak as well!

This was on my DD, an 04 GMC 1/2 ton. I've changed out the rear fluid and cleaned the diff a couple times, but haven't been in it for a while. I did put a new gasket on each time. The truck always had synthetic gear lube in it. I'm guessing that the gasket just shrunk?