Differential Cover Leaking .... bolts backing out

**79Firebird_99TA** · 10-19-2011, 01:24 PM

Since I've done the transmission, converter and poly tranny mount, my diff cover bolts are backing themselves out. I'm sure this is due to vibration.

I'm going to go back to the rubber mount and some lock tight on the bolts as well. 2 are already completely gone.

Anyone had this experience? This is weird as hell. Also is the stock 10 bolt aluminum? I read somewhere that the torque is 22 ft/lbs. I am fearful of torquing it down that much. I think I may have already stripped a couple..... sigh.

**cammed goat** · 10-19-2011, 01:52 PM

I think the stock rear is iron or steel. I don't think it's aluminum. You might have just stripped the bolts and not the holes in the rear. If the holes are stripped, look for a Helicoil kit from your local parts store.

**Smittro** · 10-19-2011, 02:17 PM

Originally Posted by cammed goat

I think the stock rear is iron or steel. I don't think it's aluminum. You might have just stripped the bolts and not the holes in the rear. If the holes are stripped, look for a Helicoil kit from your local parts store.

This... and, lock tight should always be used when possible..

Blue stuff will do just fine, the red stuff can be a bear to get loose again if ever..lol

Stock housing is iron, cover is stamped steel..

**pajeff02** · 10-19-2011, 06:55 PM

First I have heard of this issue. I installed the cover on my 12 bolt with a dab of adhesive black silicone on the threads and have had no issues. Use brake cleaner (carefully) and compressed air to clean the bolt holes thoroughly and also clean your bolts before reinstalling them to remove any oil. Then apply a drop or two of blue Loc-Tite to each bolt as recommended above.

**Spaz** · 10-20-2011, 04:39 AM

i've never heard of this happening... going back to a rubber mount will not change anything for that problem...

**Smittro** · 10-20-2011, 04:47 AM

+3.. Also agree with Jeff about cleaning out the bolt holes..

Oil or lube, even left over sealant can cause issues with thinking a bolt is tight when really it may not be tightened enough..

Remember also if you use locktite, to only apply a small amount to the bolt threads only..

Applying it into the bolt holes can/may have the same effect as having debris or oil/sealant in the holes and may not tighten enough/properly..

**79Firebird_99TA** · 10-20-2011, 12:18 PM

Good info ... thanks all.

Turns out that it was not leaking again after torquing it down tight. It had rained and smelled and looked like a leak again. So we're good to go ... but I am going to do the blue loc-tite!!

**cammed goat** · 10-22-2011, 02:30 PM

Even if you smell gear oil, it doesn't necessarily mean the rear is leaking. It is the heat/pressure escaping through the vent. I did some reading on the rearend in my car because mine gives off the odor, but there is no leak. Apparently the rears are designed to vent the heat/pressure to atmosphere.