My 95 Blazer 4x4 has a roar in the rear end that gets quieter, but doesn't go away, after I drive for a few miles. It's definitely in the rear end; it's still there after I had new tires put on yesterday. My mechanic checked the fluid level, and said he didn't see anything wrong there: the fluid was up to the fill port, and didn't look, feel, or smell abnormal to him. He recommended that I pop the rear cover and change the fluid, and take a good look at the gears while I was in there. He said it was a job I could handle. I think he's right; it doesn't seem that complex. It's a GU6 3.42 rear end, according to the RPO codes.

Are there any hidden gotchas? Is there a gasket I'll need to replace?

He said he had a 97 Blazer for a while that did the same thing, and never gave him any real trouble - but he did have a lot to say about the location of the fuel pressure regulator...

 

I just did this about a week ago to mine. It isn't too hard just have to get the cover off which can be difficult because of the sway bar and the brake line brackets. It is a 1/2 socket, I also used a wrench to get the bolts that I couldn't get with the socket.

When you refill, it will take just under 2qts of oil. The Manual says to use 80w-90, but I think some people use 75w-90. I recommend using brake cleaner to clean everything up, but make sure you let it evaporate or you mop it up.

The fill plug is magnetic so if there are any metals shavings you'll see them there or in the pan when you drain it. There is a gasket that you have to make sure u get completely off. I used a gasket from Advance Auto, but I also used some sealant to make the gasket adhere to the cover when I replaced it.


Good Luck!

 

Yeppers.. change the rear end fluid. It's not rocket science and it will make the rear end go a few more miles...

 

DON'T spray the bearings with brake cleaner!!! Just mop out the inside and reinstall the cover and fill.

 

This post >>CLICK<< is one of my favorites on the forum.

Ch-ch-ch-check it out.

Here's my saga: Click

 

Great pointer, thanks.

How do you tell if you have the 8.125 inch ring gear? I was just thinking of taking the cover to my local NAPA store to get the right gasket...

 

so i cant get the fill plug out i was wondering if anyone ever heard of using a baggy put the fuild in the baggy and puting it in and putting the cover back on any one hear of that .. any other suggestions

 

I don't think I'd want bits of plastic bag in there getting churned around by the gears. Have you tried PB blaster on the fill plug?

 

ya i gonna have to put a 3/8 extenstion in the so it can slip out maybe add some heat.... i thought i bring that up tho i saw it on tv some truck show on spike .

 

I have seen that on junkyard wars. It is more of a quick fix to get you back on the road than a permanent way to get fluid in your rear diff.