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mustgo69
05-07-2005, 03:06 AM
Should I attempt to change out my rear diff. fluid? Not scared to, just want to know what type is best, or is there a kit with gaskets I need and where to purchase?

Also, should I fool with my '02 4wd Tahoe's front diff. fluid? 50K miles on it and running good.

v10_viper
05-09-2005, 12:47 AM
It never hurts to change it and you don't have to do a gasket, just get a silicon and spread that around on it. Gear lube is some pretty thick shit so it's not likely to develop a leak.

tykrz
05-14-2005, 12:37 PM
Your Tahoe takes 75W90 SYNTHETIC Gear Oil in the rear diff.( about 3.5 litres). This because the newer trucks run a different gear angle and a very tight gear backlash. Synthetic gear oil is very incompatible with silicone and will break it and the gear oil down. If you have to use a sealer get something that is approved by GM which is non-RTV. Changing the fluids on these vehicles is relatively a simple task but using the wrong techniqies can end up costing you money.
On the rear diff , all you have to do is remove the drain plug at the bottom of the diff. Before you do this make sure you remove your fill plug first...I seen lots that are seized in place and no use to drain the oil if you can't fill it back up. Same applies with the Transfer case. This uses GM specialty fluid..not that expensive and you only need 2 litres. Auto transmission also has a drain plug. I would drain it and refill. ( about 5 litres). Unless your pulling trailers I wouldn't change the filter on that untill you get 100000KM. The front diff is also very easy..take off the skid plate... 4 bolts easy to get at... pull drain plug and refill with 80W90. (about 2.5 to 3 litres) ..and reinstall the skid plate. Note: when you recheck all the fluid levels make sure the vehicle is sitting level on the ground for an accurate check. A good rule of thumb is to have the levels on the gear boxes about 1/4 inch low from the fill plug.
the only tools you need are a few wrenches, 3/8 drive ratchet, and a plastic flex funnell.
Hope that helps...
from a tech with 20 yr exp.

mustgo69
05-16-2005, 01:41 AM
Thanks for the response.

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