Jeep XJ 1990 4.0 + Aisin AX15 5 speed

[Finn]

Hello.

Needed to get something to work with and bought this 1990 XJ with 4.0 I6 and AX15 5 speed. Needs a bit of work on the brakes and probably has at least one defective lifter judging by the sound.

According to the information on Jeep forums Mopar's original specification for Aisin AX15 transmission fluid 75W-90 API GL-5 has been wrong and it should have been API GL-3.

I have not found API GL-3 in this country but I yesterday stumbled on this information that Mopar has allowed use of 10W-30 motor oil in the AX15 transmission. I have unfortunately no further information of what sort of oil should be used or if it is all the same.

I fear I have API GL-5 in tranny and would want to change is ASAP but what should I put in there? API GL-4 or any 10W-30 mineral, semi-synth or fully synth?

 

[salv]

I have been running Pennzoil Synchromesh in my XJ's AX-15 for the last 2 years. Shift quality is very good.
I have toyed with the idea of using a 75w85 GL-4 designated MTL. GL-4 wouldn't hurt anything in the AX-15, but definitely avoid GL-5. You don't want anything too slippery for the synchros to engage.

 

[salv]

Ford XT-M5-QS 75w90 MTL would be a good choice also. It is hard to get here, but should be available in abundance in Europe considering it is made in Germany.

 

[Finn]

Thanks, guys. Good to know API GL-4 would not be end of the world for AX15.

I just bought cheapest jug of mineral 10W-30 motor oil. We will throw that in for brief moment to flush the old stuff out and then put in the better stuff. Engine will get Mobil Delvac Super 1400 10W-30 for now.

 

[salv]

Good choice of oil. I wish I could find Delvac 10w30 around here.

 

[dlundblad]

Very good looking and clean Jeep. At that age in Indiana, it would be full of rust.

 

[901Memphis]

Mobil 1 10w30 would work well. People use that in their supercharged gm engines too.

 

[KCJeep]

Is that a Treadright tire?

Go JEEP!

 

[Finn]

Front tires in picture were something I left for the seller and got those original wheels instead. Tires were a brand new set of 31" or so but they were far too coarse for my intended use.

 

[Zaedock]

The front tires look like Simex centipedes.


My daughter has an '89 Cherokee 2 door. 4.0L/Auto with slightly trimmed fenders to fit 33's with only a 2" lift.