salinity

Hi all - I recently had the tranny fluid changed on my 95 2.5L XJ (AX-5 tranny) from whatever was in it (pretty thick, viscous fluid with some water definitely in it) to 10w-30. I changed it due to loss of fluid when I pulled out the driveshaft to take a look at the U-Joints.

Driving around town all seemed well. However, during highway driving in 5th gear today, it was whining noticeably. The sound reminded me of what you hear when a hydraulic lift is being lifted. I could get the sound to change in intensity a bit by moving the shifter around while in 5th gear. It doesn't make the sound in any other gear. Oddly, the sound seemed to diminish over the course of the 1.5 hour drive, but was still faintly noticeable by the end of the drive. Any thoughts what this could be? It was the first 5th gear driving I've done since having the fluid changed - could the change in viscosity between the old fluid and new 10w-30 be causing this new sound? Does new fluid need time to work around to parts of the transmission (this seems unlikely to me)?

As an aside, I didn't end up replacing the u-joints, but the substantial vibration I was feeling when going uphill at 60-65mph (the reason for pulling the driveshaft in the first place) was much less pronounced.

salinity

Another thing I thought of - when trying to asses the tranny fluid situation, I mistakenly removed the torx bolt "DO NOT REMOVE" plug located on the drivers side. I've read removing this plug / bolt is of no consequence, but I've also come across mention of it having something to do with a 5th gear detent ball and spring. Would a whining be a symptom of something I let loose when I pulled that plug? I didn't notice any sort of spring, etc, but now this has me a bit concerned...

firehawk618

I cannot say for sure on your trans but in most other manual trans, when you pull that bolt the reverse counter gear lever will fall into the transmission. Very bad.

salinity

Hmmmm - I've read there may be nothing behind that plug and nothing came out when I pulled it (it was a threaded hole just like, I assume, the fill plug on the other side).

IF something like the reverse counter gear lever (can't find that precise part on an AX-5) came out, what would be the symptoms? I still have reverse and all other gears - just a whine in 5th.

Larry's XJ

10-30 is what it calls for? Is that a "gear" oil, or plain motor oil?
What type did you use?

salinity

The updated Chrysler spec for the AX5 and AX15 is 10w-30 (motor oil) - the Mopar part number for the transmission fluid actually points to 10w-30. GL3 is no longer available and GL4 is hard to come by (Redline is the only one I know of). There are numerous threads on numerous forums on this topic and there is also a TON of opinion as to whether this is right, good, etc or not.

I plan to change it over to Redline or at least synchromesh (ok for brass synchros) once finances and time allows - does anyone with knowledge of AX5s think I am taking a risk in waiting a bit to change it over (3mo. 1500 mi or so)? I'm not sure if the shop put regular or synthetic in and the mopar part number just says 10w-30 - it doesn't distinguish.

Fred/N0AZZ

Did you check the transfer case fluid level?

salinity

2WD, so I don't believe I have a transfer case under there (right?)...

JandDGreens

When we looked up what should go into my 5spd. we came up with the same gear oil we put in the differential. The guy looked it up on the computer for my 91 XJ. After I changed mine, I had some issues with the sincros but after 5,000 miles or so it is fine.

Larry's XJ

Only asked for educational reasons. Didn't mean to infer you were wrong

salinity

Ha - I only answer for educational reasons as well - no worries! As to if I was wrong...well, the jury is still out on that one.

The shop offered to ensure they filled the trans up proper tomorrow, so I may take the opportunity to have them throw some synchromesh in (I can't get redline locally). It's still on the lighter thinner side, but I'd feel better with it in the tranny than the 10w-30. I'll likely look to go with some redline this spring unless the synchromesh is outstanding.

Turbo X_J

Counter 5th gear rides on a roller bearing, bearing is probably on its way out. The previous use of heavier gear oil covered the noise.

Fred/N0AZZ

Yup like using saw dust mixed with gear lube to cover up a bad rear end nice and quiet