I hate to start a new thread for this, but I can’t seem to find an exact answer.

I want to change the manual transmission fluid on my 2000 XJ using Redline MT-90 and figure I’ll go ahead and do the t-case fluid as well. For automatic transmissions, I have found that it is recommended that you use the same fluid in both. I am under the impression that the same is not true for a Manual XJ.

So to clarify, should I use Redline MT-90 for the transmission and Dextron III for the transfer case?

Also, if anyone knows of a “Ultimate Manual XJ Guide” sort of thread, I will be your best friend if you can share that link

 

Yes use automatic transmission fluid in the transfer case. Make sure you open the fill plug first before you drain the fluid. See article for more info
https://www.cherokeeforum.com/how-to...e-fluid-399038

I use MT90 myself in my AX15. Made a huge difference over whatever ancient watery liquid the previous owner kept inside it. I actually drained the original, ran regular 10w30 motor oil in it for like 100 miles, then drained it and used the Redline oil. It was pretty nasty when I first drained it so I ran the regular oil to kinda wash it out so to speak.

One of those transfer bottle pumps is really great to have. I didnt have one at the time so to fill the trans I used a long hose snaked up through the engine bay to a funnel. There ain't much room down there

 

Nothing wrong with using the redline oil but I had good luck with pennzoil syncromesh as well. It's a bit cheaper.

 

Agree - ATF in the transfer case, MT-90 in the transmission. Works great. Definitely make sure the "Fill" plugs can be opened successfully before opening the "drain" plugs and get a decent fluid transfer pump to fill with. Even with a decent pump, be ready for some tedious, muscle cramping pumping to fill the tranny.

 

Awesome, I have a transfer pump that I got from Harbor Freight when I did my rear differential. It worked really well except for one thing... it had these stupid wings on the end of the nozzle that goes into the fill hole that are supposed to press against it to hold it in place... well they went through the hole and spread out and got stuck in the differential so I had to take the cover off to get it out and make a new gasket. That was fun, I went ahead and cut the wings off after that haha. Thank you guys for the info, that link with the diagrams is super useful.

 

The Harbor Freight one is nice - it moves a much larger volume of fluid than the dinky bottle top ones. I've always used my Dad's (since he has one I've never need to buy one for myself) and there were no wing things on it. I guess he came to the same conclusion as you that they were not good.

Just make sure you clean the pump between uses so you don't contaminate the fluids.

 

What he says!
I also use Pennzoil Syncromesh. Got to keep the sulfur type fluids away from brass syncros, like in our AX5/AX15 transmissions.

 

When I filled my ax-15 I took out the fill plug (to get the correct level) then just popped the shifter out and filled through the top. Seemed a whole lot quicker and easier to me. I hate using pumps for diffs and stuff.

 

I haven’t changed the transmission fluid quite yet. I have the nv3550 transmission and read on some forums that I should be using Redline MTL and not MT-90. I don’t want to put the MT-90 in if it is going to cause issues. I’ll just try to return it or sell it on FB if it is a bad idea to use it. Any thoughts?

 

I'm getting ready to change manual transmission, transfer case, and forward and rear differential fluids. This thread is very helpful.

One question I have, though, is: Do the drain plugs have any type of crush washer or rubber seal that need to be replaced?

Thanks!

 

Can't speak for the manual transmission but no on the other ones.
Might want to replace the rubber plug in the rear diff though.

 

Manual tranny is also a no. I've done both AX15 and NV3550 and both used metal washers. I suppose you -could- replace these if you wanted, but I never have and never had a leak.

Make sure you can get the FILL plug off before the drain plug on both tranny and transfer case.
On my 95 the plug hex head sizes are freakin' huge (over an inch for xfer, 20-something mm on the ax15), so make sure you have a wrench or socket (I prefer the socket) of the correct size - they did vary somewhat over the years so it's best to check yours directly.

 

OEM fluid for tcase is DexIII. Novak Adapt reports that some of their customers have had luck with 10w30 or straight 30 weight engine oil in the tcase. I personally run DEX III but the t-case isn't a complex gear box it's probably not real lubrication picky as long as it's not too thick for the pump to move.