98 JGC Laredo with I6 and select trac. (TC 242 right?) (ATF+4 or Mercon?)
Just did a trans filter change (Thought I had a 42RE or 44RE but the filters at autozone didn't look like the one I pulled so I asked about the 46RE, Identical so I guess I have the 46RE, right?) I used ATF+4
I want to drain both differentials. The service manual calls for silicone but I notice there are gaskets at autozone. (Gaskets, Yes or No?)
Totally confused on gear oil!
Do I have Limited slip differential? (Thus needing FM?)
Is there a gasket joining both halves of the TC? (Looks like a piece is hanging down)
Appreciate your advice/info.
Thanks

Either fluid will work fine in the transfer case.

I'm pretty sure ATF+4 is correct for the transmission. If you do not have an owners manual to check, give the dealer a call to be sure.

Go for gaskets in the diffs. Just make sure the gasket surfaces are completely clean and grease-free before installation.

Many gear lubes have the FM included, but work fine for open diffs. If in doubt, just use a lube specified for limited - slip applications. It will not harm open diffs, it's just a couple of bucks more.

FWIW the front diff is open. The rear might be LS. You can find out for sure by lifting both rear tires in the air with the parking brake released.
Turn one tire. If it turns easily and the other tire turns in the opposite direction, it's open. If it's stiff to turn, pop the trans in neutral. If both rear tires turn in the same direction and the driveshaft rotates, it's LS.

There should be a gasket where both halves of the case meet. So long as it is not leaking and the bolts are reasonably tight, don't worry about the hanging piece.

Thanks for your help. Is the limited slip like the old posi rears from the 60's?

Thanks for your help. Is the limited slip like the old posi rears from the 60's?
Same, Posi Traction was a trade name.