yes, you need to remove the plate, might as well just get a new cover and gasket while youre at it, cheap insurance if yours is rusty

 

I just read the previous thread on this topic (from swartlkk). Looks like I will have to take out my differential cover plate if I want to change this stuff. Man I am not looking forward to this.

Thanks,
JC

 

Well this past weekend I finally changed the gear oil in my rear axle on my 1993 S10 Tahoe. I was surprised that this truck has over 185k miles on it and the rear axle fluid was in remarkably good condition. I am the sole owner of this truck as I bought it brand spankin new in 1993 from Dennis Fronrath Chevrolet in Delray Beach, FL. Over the years I did many repairs on the vehicle some quite frankly caused by boneheaded assembly people at the GM plant in Ohio where my truck was built. Right out the dealer the truck had problems with the front shock absorbers. It also was missing a head gasket on one of the cylinder heads. However, after all those repairs not once did I change or even check the rear axle gear oil. When I checked it recently it was low by only about 250ml. This saturday I pulled the cover off and a dark golden colored fluid poured out. There was some sludge on the gears to be sure (I removed it all with brake fluid cleaner aerosol) but overall the fluid looked in remarkably good condition. Not a drop of water to be found anywhere. After a hell of a time cleaning out the old paper gasket material from the gear housing and cover I was able to seal it up with Permatex RTV and add 1.5 quarts of SuperTech (aka Mag 1) Synthetic Blend 75w90 gear oil and 1 quart of Royal Purple MaxGear 75w90 gear oil. The Royal Purple was a left over from a similar maintenance job on my 2005 Toyota Tacoma TRD Sport. Overall I am very pleased with how things came out. So far not a drop of oil anywhere is leaking from the cover and the the shifting seems to be smoother with better acceleration. Thanks to everyone who provided advice on where to find the fill plugs and what type of gear oil was needed.

 

i couldnt find my fill plug at first either, so much crud everywhere had it completly coverd. it had close to 180,000 miles on it and was very nasty, low too. spider gears looked awful. after the job was done i has a axleshaft leak, so i took things apart again & replaced both axleshaft seals. ive noticed that if im riding in the back of the vehicle i can hear the rear end. if it goes out on me, i'll just swap the whole assy for the axle from the '95 parts blazer. only bad thing is that its a different ratio, i'll have to swap the front out too or take off the front driveshaft so 4wd doesnt accidently get used. the '97 (good) blazer is a 3.42 while the parts truck is a 3.73 ratio. the parts blazer does have a G80 though. but considering it had nearly 200K when parked, im not sure the G80 would still even work.