Rear Axle Housing Cover Bolts

[Pancho]

Received my Helm's manual(s) last week and while going back over some of the maintenance I have done on my truck I see where they say, "Do not reuse the rear axle housing cover bolts." I of course reused the existing bolts when I changed the diff fluids at 10,000 miles. Anyone here see any problems with this? I should note that there is very slight leakage on the pumpkin that I suspect is coming from the check plug.

[MarkD]

From what you are saying, it sounds like the bolts are Torque-to-spec bolts.

 

I wouldn't worry about it though.  I probably won't replace them when I change my axle fluid.

 

What Fluid did you go with?

[Pancho]

I used Mobile 1 75w-90 in the rear and GM 80w-90 in the front. Does anyone have an idea on the cost of the replacement bolts?

[Colorado Kid]

I don't know about the price of the bolts, can't be more than $1 each though.

 

I'm just curious as to why you removed the cover?  I was very pleased with GM (or Eaton) for putting both drain and fill plugs in the diff so I didn't have to pull the cover.

 

If I was going to replace the bolts I'd get a new gasket too, but then I guess I'd need more Lube and I'm NOT going to buy 4 more quarts of that $30/qt GM synthetic 75W-90 grape kool-aid gear oil!  If mine leaks I'll keep an eye on the level and keep it full, but it'd have to be pretty bad to convince me to pull the cover.

[MountaineerTom]

I pulled mine off soley to clean the crud off the magnet.

 

Just over 22,000 miles.

[Pancho]

I am new to servicing my own vehicle (always left it up to service department in the past) and thought it would be simple enough to take a look inside and clean it out. The service department thought I was crazy to mess with it with such low mileage. They gave me the gasket for free and confirmed that the Moble 1 would be fine for the rear. The only reason I put GM 80w-90 in the front was due to an order I made with GM PartsDirect for the Delco oil filters (hoping Mobile 1 comes out with an oil filter for the 2500HD). I might add that I'll think hard about using GM PartsDirect again due to the handling charges.

[Colorado Kid]

I know what you mean about those handling charges!

 

I buy the STP 9100 oil filter for 4.99 at Autozone.  It is made by Champion Labs as is the Delco PF 2232.  They are not identical (for example the STP does not have the flats stamped into the end of the can, which in my experiance makes it less likely to crumple instead of turning when you go to take the amazing self tightening filter back off.) but seems to be of similar quality.  I haven't cut them apart, but they are similarly heavy, have similarly reinforced flanges, identical gaskets, same anti-drain back valve, etc.

[swl2126]

Where is the rear differential drain plug for a 2500HD?

[RyanbabZ71]

should be on the bottom of the rear diff (pumpkin).  It is a circle / square cut out to get it off

[swl2126]

Found the drain plug.  What are the capacities of the front and rear differentials?  Also, what is the bolt torque for the cover bolts?

 

Thanks,

[Pancho]

Rear axle cover bolts should be 30 lb ft.

[CMNTMXR81]

They are "torque to yield/torque to spec" bolts.  Essentially they stretch a little as they are finally torqued.  However, since they aren't under pressure such as the head bolts (as they're also "torque to yield") it isn't as crucial to replace them after removing them.

 

I'd simply re-use them too.