AX-15 Oil Change and Shifter Overhaul

[Anak]

I am writing this up because every time I go through this process I find I am missing something, invariably something that is not readily available locally.


Here is the list of everything I want to have on hand next time I do this:
4 quarts of Redline MT-90 or MTL
AX-15 shifter overhaul kit (rubber boot, polyurethane spacer/washer/pivot & shifter ball bushing)
Replacement tunnel boot (get one for a TJ, they don’t seem to offer them for an XJ anymore)
Replacement console boot


There are two reasons for combining these two jobs. For one, it is much easier to fill the AX-15 from above than from below, and for another, the shifter and rubber boots probably all need serviced. Again.

Here is one of the reasons this job needs done this way:

I had never before realized it, but there is a piece missing at the bottom of that recess. From what I have read from others it is pretty common for that bottom washer/cup to be missing. No need to try to guess where it goes, but I would much prefer it didn’t go there. Better to replace it before giving it the chance.

And there are three rubber boots that probably all need replaced too. This one on the shifter is the biggest challenge:

There is also the one that seals the tunnel:

And there is the one for the console:

That one for the tunnel and the one for the console were replacements about 7 years ago. As you can see, they are due for replacement again. Lamentably I did not have their replacements on hand as I did not realize they had those holes in them until I removed them. They got reinstalled as they are this time around. Hopefully next time I will have ALL the parts I need.

I ordered a shifter rebuild kit off ebay. This is what I got:

This rubber boot was the part I was certain I needed:

In previous oil changes I had not been able to locate that part all by itself. I used a nitrile glove over the shift tower instead.

The other two pieces in the kit I wasn’t entirely sure I needed, but I decided to get them just to see what they were and where they went.

This part turned out to be something I really needed:

I had never realized that part was missing from my shifter.

And then this part:

That shows the new one next to the old one. When it was all said and done I decided to run the old one. I wasn’t impressed with the new one. It fit with more slop than did the old one.

 

[Anak]

The process of separating the two parts of the shifter is a bit of a pain. Here is where they join together:

Before taking the shifter apart I marked the two halves so I could certain of orientation for reassembly:

A vise and a pair of pickle forks works well for getting the two halves apart:

Once the two halves are apart it is a good idea to grease the boot and the square bar it has to slide over:

Then the two halves of the shifter can be reassembled, with attention to orientation:

Note that it took a bit of force to get those halves back together. Several whacks with a hammer were required. And yes, I added a bit more grease in hopes of making the job easier and keeping the rust at bay.

 

[Anak]

Now to deal with that washer that belongs underneath the shifter. Looking into this I found that some people warm it up first while others install it just fine without warming it up. I decided that since everything was at about 40 degrees it would make sense to warm it up:

I cleaned up all the old grease in the bottom of the shifter tower:

Then I got the washer down underneath the pin on one side:

Then I got a fairly wide screwdriver to use as a ramp to slide the washer past the pin on the other side:

Slid the washer down and seated it in the bottom:

If you haven’t done it already, now is the time to drain the transmission. Either a 15/16” or 24mm wrench will do:

The AX15 takes 3.3 quarts. Filling from the top I aim to put in 3.5 quarts. Whatever you do, DO NOT USE GL-5 gear oil. That stuff is bad for your synchros.

Once it is time to reassemble the shifter you will probably find that it is harder to get the lock ring to rotate. That new washer at the very bottom makes a difference. I found that a Torx driver worked well for persuading that ring to rotate:

The nice thing about the Torx driver is that it won’t so easily slide off the ring.

To get the rubber boot into place on the top of the shifter tower I used a cotter pin pick:

[FONT=&quot]The trick with that is to not puncture the boot with the tip. You could probably also round off the tip of a piece of welding rod and bend it to serve as an installation tool.[/FONT]
[FONT=&quot]
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[FONT=&quot]Beyond that it is just a matter of reassembling everything you took apart. And then enjoying an improved shifter. But it will still shift like a dump truck.
[/FONT]

 

[asymptonic]

A dump truck perhaps, but once you've trained on it for 22 years you can still drive it like a race car. Nice writeup!

 

[Runnin'OnEmpty]

Mine shifts itself, but I still enjoyed those fine pics.

Good job!

 

[cherokeecrawler]

Anybody ever messed with the short throw kit they sell for the ax-15?

And agreed, nice write up Anak.