So my 1/2 hr of "I'll change the rear-diff gear oil" is now "how the *&#$ am I going to get that bolt out?"



I broke one off flush with the face. (yes, by hand, I know better than to use the impact on old bolts like that)

What's your school of thought here...left hand drill bit and extractor? Torch? Weld another bolt to the face of that one and try to work it out?

Your experience here is appreciated.

On a positive note (if there is one here), it was one of the bottom bolts, right beside the very bottom center one, so I can get a drill/extractor/whatever on it at least...

 

Maybe a little heat from a propane torch after you center drill it for an easy out.

 

Center punch the center of the bolt, use a left hand drill bit and drill downs about 1/2". Then the extractor. 90% for the time the heat and vibration of the drill will walk the bolt right out, no extractor needed.

 

I guess it's a good thing I did it. From the look of these bolts and the condition of the gear oil, it's never been done. 140k and almost 20 years....

 

I had to change a bent axle in my z, and drained the fluid in a tub. Then left the tub in the garage all night.. I walked in the garage the next morning to a very potent smell form the gear oil.. No clue if it was from not have been changed be for or what, but it was terrible. On top of that it was very thick, thicker the 80/90.

So pretty much, just seeing if yours was the same?

 

Yea, pretty sure the disgusting smell is from the limited slip additive. That stuff is rank.

The gear oil that came out was pretty think and gooey...again, probably original. 140k kms and 18ish years is a long time to ask oil to do it's job I think.

 

What, were you tightening the cover bolts using a breaker bar with a pipe extension?
You don't need to horse those bolts on. A little bit past snug is good, kinda like how you would tighten down a spark plug, assuming you don't go animal on those as well.

 

What your smelling is the Extreme Pressure additive package that all gear lube has. It will stay in your memory for life. If you think that is bad, you should smell it when you burn up a bearing and it now has a burnt smell on top of the EP additive smell.

 

Nope, removing them, not installing...

2 of them were locked solid...I managed to finesse the other one out, but this one broke.

I was using a breaker bar on them to get them loose, but not much choice there. They were all really tight. I have penetrant in each of the holes now, will run a new bolt into each to chase the threads before putting it back together.

I am waiting to hear back from my local chev dealer to see if he has a new cover in stock or if I have to order one.

Can I just use regular Gr 5 5/16 bolts on these or do I need to order specific bolts? Other than the 2 with the parking brake cables being a bit longer, they look like normal 1 1/4" bolts...

 

Since the oil has an organic based you could be smelling bacteria. Engine oil sees extreme heat and automatic transmissions see heat and pressure. Rears and manual trans are breading grounds for bacteria. This is very common in gear boxes used in industry. Most of us have switched over to synthetic oils just so we do not have to deal with the MSDS (for the nasty chemicals) of the biocides additives the gear boxes require.

You want to talk about bad smell, some of the old 4X4 you know went thru a few swamps. Wow they could make you throw up.