Noob question - AX-15 5-speed manual

[ridgeone]

I have to admit that I'm completely new to Jeeps and manual transmissions in general. I always wanted an XJ and always wanted a vehicle with a manual transmission. Well, for professional reasons, neither of these wishes ever made sense until now. I finally bought a nice 97 XJ with 75K and the AX-15 manual now that I have a job that justifies it. My questions are hopefully simply answered. Firstly, I'm the third owner of this XJ and I was curious as to what the life expectancy of the OEM clutch was? To elaborate, what should it feel like with 75K on the clock? I'm trying to find out if it's due for a replacement and if so, the second half of the question is if aftermarket is the way to go or stick with OEM? I am considering adding a Hurst shifter and Centerforce II clutch. Has anyone tried this combonation and how's it working out? In addition, I'm curious as to how everyone else's AX-15 feel from 1st to 2nd. Mine feels a little clunky and smooths out from 2nd to 3rd and from 3rd to 4th. Should I be looking so much at the clutch or focusing more on the slave cylinder or synchros in the transmission - Or, it that just how the AX-15 feels from 1st to second - a little clunky. Thanx - RJ.

 

[87manche]

mines more than a little clunky. Most guys around here swear by redline MT-90 to put in the AX-15. Apparently it smooths it out a bunch. a 75K miles you should be changing every fluid in the Jeep anyway, just for piece of mind since you just bought it and don't know when they were done, if ever.
Things with fluid:
Tranny: 3.5 quarts gl3 gear oil, MT-90 recommended for smoother shifting
Diffs: about 4 quarts total, 75-90W gear oil,75-140 for towing
t-case: about 3 quarts dexron ATF
As for the clutch, mine engages about midway through the pedal and is smooth. It shouldn't chatter. It might be advantageous to have someone more experienced with how a clutch feels try it out.

 

[edmaude]

1-2 is a bit stiff especially when cold. I just switched to Redline MT-90 fluid and it is much better in general. At 75k I would change to fluids anyway

 

[Kejtar]

All I can tell you is what I remember from my clutch replacement:
1. it went at about 120K
2. don't let them resurface the fly wheel for you: it needs to be replaced as it can't be really resurfaced: in 97 it has some sort of a concave shape to it and should you resurface it it won't work too good (don't ask how I know)

 

[mdl]

Where in mass are you?

 

[gmars]

clutch on my 97 5-speed was still good at 140 k. had a motor meltdown and popped in a new block - pita. my motor guy replaced the clutch, and said it still had soem life left, but not much. new clutch is tighter, but does chatter a bit at times. got a lot of rumble in 5th, also.

 

[ridgeone]

West Springfield, MA.

 

[ridgeone]

Thanks a bunch to all who have replied so far. A couple of guys at my work have had jeeps and still drive manuals (it looks like a toyota tacoma convention around here sometimes). I was going to have one of them take it for a ride at let me know what they thought. I really appreciate the info on the fluids. I planned on changing all the fluids next week and wasn't sure what to use. As for the clutch, does anyone have an aftermarket clutch? Anyone had experience with Centerforce? How about the Hurst shifter?

 

[sflier]

I can't speak about the Centerforce as I've never used it, but (IMHO) I think I'd skip the Hurst shifter. The AX-15 is a truck transmission and wasn't designed to shift quickly. It's a clunky shifting unit even when brand new and was engineered for strength rather than performance. I suspect you'd be frustrated with the results.

 

[ridgeone]

Well, that makes sense. I didn't really expect to shift like a BMW but I really had nothing to compare it to except a 2005 Rubicon 6-speed that I test drove - pretty smooth (German tranny). As for shifter, thanks for the input, you've probably saved me a couple hundge in costs. I was waivering anyway. I guess I'll just wait until I change the fluids in everything before I decide on the clutch. Thanx everyone for the input - this site is great! RJ

 

[montanaman]

I've got a '91 with an AX-15 in it ... 195,000 miles and still pretty strong.

Shifting from 1st to 2nd is a little tight or "notchy" as they say. I put in Redline MT-90 synthetic and it improved a lot ... still a bit tight on cold mornings, but overall, much better.

One important thing ... do NOT use GL-5 rated gear oil in your tranny. It has sulfur additives that turn into sulfuric acid and cut the life of your brass synchro rings. Use a GL-3 rated dino oil (read the label for the rating) or the redline MT-90. They don't have the extra additives.

Just bought the jeep a few months ago, and put in a new motor and new clutch. I went with the OEM clutch design and I'm very happy with it. If you don't plan on doing a lot of serious off-roading that requires heavy clutch work, or if you don't plan on doing any stoplight grand pris racing, I'd recommend sticking with the OEM design. A good source is http://www.clutchcityonline.com Good prices, great service on the 800 number.

When I'm on the highway, it makes some low noise in 5th gear. I suspect that's age speaking. I'll probably get it overhauled at a local shop around 250k.

 

[RyanM]

my96 130K, originial clutch. 1st and 2nd adn 3rd' are clunky unlessyou shift at the exact right time.

my other xj went 200K on originial clutch the ax15 in that shifted better than my 96.

my freinds YJ has a centerforecII with brand new slave and flywheel and everything else. Very strong. ive seen him get down on this thing very hard, rarley have i ever smelt it burn. he swears by it

i just swithced my motor over to Royal purple, and im about to do royal purp throughout the whole vehicle. good stuff

 

[Dr. Dyno]

I have to admit that I'm completely new to Jeeps and manual transmissions in general. I always wanted an XJ and always wanted a vehicle with a manual transmission. Well, for professional reasons, neither of these wishes ever made sense until now. I finally bought a nice 97 XJ with 75K and the AX-15 manual now that I have a job that justifies it. My questions are hopefully simply answered. Firstly, I'm the third owner of this XJ and I was curious as to what the life expectancy of the OEM clutch was? To elaborate, what should it feel like with 75K on the clock?

The clutch life expectancy depends on the type of driving that's done and how well the driver treats it. A lot of gearchanging in slow city driving will wear out the clutch before 100k miles but if the driving is mainly cruising on the highway in 5th gear, the gearchanges will be far fewer and the clutch could go beyond 150k miles. I'm still on my second clutch at 198k miles (the first one was replaced at 112k miles) so I'm somewhere in between.
The AX15 tranny is near bulletproof and can handle 350lbft without any problem, but the gearchange does tend to be notchy for the first few minutes after a cold start in cold weather. It's also not unusual to have to double declutch sometimes to engage reverse.
The Hurst shifter really does shorten the throws quite a bit but is it worth spending $180 to buy one? I don't think so unless you're gonna be spending a lot of time on the dragstrip. The AX15 doesn't like to be shifted in a hurry and it won't quite have the rifle bolt action of a VTEC Honda Civic gearbox even with the Hurst shifter.
As far as the Centerforce II clutch goes, I've only heard good things about it.