changing rear differential oil?
Moderator: F9K9
changing rear differential oil?
First off can anyone tell me how many quarts I need to put back in? I know it's the 80/90. Also, when I removed the cover and the oil came out there was a lot of brown sludgy type stuff, kinda like when a diesel truck gets water in the oil. I have never changed the oil on the differential before, everything is sealed tight, no leaks. Is this common? It just doesn't seem to look right.
[size=75][color=blue]2003 S-10 crew cab[/color][/size]
[size=75][color=red]6in superlift[/color][/size]
[size=75][color=red]6in superlift[/color][/size]
-
killian96ss
- Crew K Elite
- Posts: 2669
- Joined: Tue Sep 09, 2003 11:53 am
- Location: Sacramento, California
Yep you have water in the oil. 
The first time I changed my oil it looked the same way. The likely culprit it the rear axle vent tube. Look between the bed and the cab and if you can see your vent line then that's how water got into the diff. If your vent line is in this area the then you will want to move it to a better location that won't get wet as easily. There is a TSB for this exact problem. Get all of the old oil out and clean out the bottom of the diff that won't drain. Next you'll want to spray the entire inside of the diff housing, gears and G80 locker with WD40. This will help displace most of the moisture. Be sure to rotate the gears while spraying so that you get everything covered. Now you want to clean out the residue in the bottom of the diff and reinstall the cover with a new gasket and fill to the proper level using the fill hole on the right side of the diff. Make sure your new gasket has the proper oiling holes on the sides to allow oil to reach the wheel bearings. This would be a good time to upgrade to a nice aluminum cover with bearing cap pre-load bolts. 
I think my diff took between 2-3 quarts to fill up. 
Steve
The first time I changed my oil it looked the same way. The likely culprit it the rear axle vent tube. Look between the bed and the cab and if you can see your vent line then that's how water got into the diff. If your vent line is in this area the then you will want to move it to a better location that won't get wet as easily. There is a TSB for this exact problem. Get all of the old oil out and clean out the bottom of the diff that won't drain. Next you'll want to spray the entire inside of the diff housing, gears and G80 locker with WD40. This will help displace most of the moisture. Be sure to rotate the gears while spraying so that you get everything covered. Now you want to clean out the residue in the bottom of the diff and reinstall the cover with a new gasket and fill to the proper level using the fill hole on the right side of the diff. Make sure your new gasket has the proper oiling holes on the sides to allow oil to reach the wheel bearings. This would be a good time to upgrade to a nice aluminum cover with bearing cap pre-load bolts. I think my diff took between 2-3 quarts to fill up. Steve
Thanks Steve for the quick reply. I knew something wasn't right I just didn't know what. I'm done for the night. I've got the cover off and a towel wrapped around everything while it's still dripping oil. I will start again tomorrow morning and get it all cleaned out. Geez I knew something like this would happen when I started this! But I knew it needed to be done. I'm off work for a couple weeks so I've got time to deal with it. Lucky me
[size=75][color=blue]2003 S-10 crew cab[/color][/size]
[size=75][color=red]6in superlift[/color][/size]
[size=75][color=red]6in superlift[/color][/size]