Transfer case flush?

[ledslinger]

Originally Posted By: Rob_Roy
I think you are making this more complicated than it needs to be. I understand that you want to get all of the old fluid out, but you don't need a solvent rinse to accomplish that. Take the truck for a nice ride to get everything warmed up, then drain the current fluid out of the t-case. Refill with some el-cheapo 80w90 and drive the truck normally for a week or so, then drain and refill with your preferred gear lube.


I would do this or just do a normal change with the fancy fluid. Or do a rinse with a quart of cheap stuff, poured into the fill hole and flowing out the drain.

 

[GMorg]

Things can settle in the bottom of the transfer case and can be resistant to mixing by driving. I have a thread hear somewhere explaining my observation of MoS2 settling in my T-case. In the end, I used a big can of WD-40 to blast the gray mess out of the bottom of my T-case. Like the OP, I only had access through the drain and fill plugs.

 

[yonyon]

I don't like the brake cleaner plan at all. Isn't it going to puddle in the bottom of the transfer case? How about this happy medium:

-Drain it out.
-Spray out the bottom through the fill hole using air if available otherwise using CO2 or "canned air" (usually a HFC that boils off in a matter of seconds) or propane.
-Replace the drain plug and add 1 qt of cheap Dexron type ATF.
-Drain it out.
-Spray out the bottom through the fill hole using air if available otherwise using CO2 or "canned air" (usually a HFC that boils off in a matter of seconds) or propane.
-Replace the drain plug fill with suitable lubricant.


The ATF shouldn't thin the fluid you're leaving in there as much as parts cleaning solvent. Just using a bit of the lube you really want in there is even better if it isn't too expensive. Using something that's normally a gas at room temperature for blowing away the puddle means you don't have to wait so long as for parts cleaner to dry.