Stronger Transmission

[familyofjeeps]

Hey all,

I have a 1988 Jeep XJ with the AX15 5 speed, the transmission has done fine for driving around town and the little bit of off roading I have been doing. Now that I am being a little more aggressive on the trails and tackling bigger obstacles I have gone though 4 now, and I am tired of it. I don't know much about them, so I am looking for some advice on a stronger transmission that will handle what I want to do with it. Any information would be awesome.

Thanks.

[fug]

There's nothing wrong with an AX15 for wheeling.  I would drive it til it blows up then look at replacing it.  Tons of Ax15's on the trail.  It's a fairly desirable transmission... just ask someone with a puegot tranny

[familyofjeeps]

ok, is there anyway to beef it up then?

[vantagetes]

What are you breaking?

There are all sorts of stronger tranmissions, the question is how much work would you like to do making them fit?

[familyofjeeps]

I haven't taken this transmission out but this is what's happened. It wouldn't go into reverse or 5 gear when I started the day, after about an hour of driving it would but it was hard to do.

I am just looking for something that I can abuse and not worry about it, with keeping in mind a working mans budget. I understand that there is maintenance and sometimes you are going to brake parts on the trails. Does anyone run an aftermarket transmission and how do they like it?

[JackstandJohnny]

back the truck up.

you've gone through 4, FOUR transmissions?  like, completely grenaded them? what are you running for tires/etc. 

if you've taken out 4 ax15s theres probably not a transmission you can't kill

[Marco]

im pretty hard on my ax15 with 37" tires and havent wrecked one yet.vantagates is right, it would be nice to know why (or what peice)  got effed then we could decide if the tranny sucks or if there is another component causing it.

[Bnine]

Are these transmissions comin out wet?

Its important to extend the vent if you play in mud and water.

The 4.0 doesn't really have the power to destroy AX 15's on a regular basis.

Your only real option for an upgrade is a NV4500 using an AA bellhousing.

Cost is roughly 1000-3000 depending on what you find for a deal on the unit and its condition.

A 4500 in an XJ would reguire severe floor cutting in order to fit without hanging 6 inches below the "frame" rails.

[Evil-Jeep]

back the truck up.

you've gone through 4, FOUR transmissions?  like, completely grenaded them? what are you running for tires/etc. 

if you've taken out 4 ax15s theres probably not a transmission you can't kill

He can't back the truck up - no reverse... J/K

Seriously though 4 trannys??? It might be better to consider other alternatives to the problem other than the transmission causing the problem.

What kind of lift any have put in?
A body lift can cause problems with the shift plate, and not allow the shift leaver to properly engage the gears, causing all sorts of  destruction.

[frenchy]

...wouldn't go into reverse or 5 gear ...

Had an XJ that did this before, turned out to be the passenger side motor mount was fubard.

A body lift can cause problems with the shift plate, and not allow the shift leaver to properly engage the gears, causing all sorts of  destruction.

Or yeah, remove the body lift in that XJ 

[SwampSinger]

4 trannies? Holy molly man!


Just  take it easy on the skinny pedal and stay out of the mud. Finesse is key and mud kills Jeeps !

I've been running an AX15 ...it's been in my Jeep for 12 years now and I've been running 37" tire for 3-4 years also.  I went through a few clutches but the transmission has been good to me.  My synchros were going, so I put Lucas synthetic 75W90 in it and it really helped with this issue. All my vent lines have been elongated and I change my fluid in it once a year (it comes out nice and clean... no water in it).

a little love goes a long way...

and make sure to take that bodylift out of there 

[Possum]

I have a 1988 Jeep XJ with the AX15 5 speed

Did you swap in the AX-15?  Thought all 88XJs had the peugeot.  

On my 88 I swapped in an NV3550.  Not exactly a direct bolt in though.  
- different pilot bearing
- line coupler for the hydralic clutch.  The XJ used a metal line and the NV has a plastic line.
- re-drill the transfer case mount holes on the rear of the transmission since the cherokee transfer cases are clocked down further than the wranglers
- fab the crossmember to mount to the new trans
- fab a transfer case linkage bracket
- shorten the stick shifter 2 - 3 inches

They make a kit for it here:
http://www.high-impact.net/transmission_and_gear/nv3550_Peugeotreplmt.htm

I'd imagine the AX-15 is an easier swap, but I wanted the NV.

[SwampSinger]

I'd imagine the AX-15 is an easier swap, but I wanted the NV.

We replaced the Peugeot out of XJHERO 88 Comanche with a 98 XJ AX15.


There were just a few challenges with the pilot bearing and the cross member but over all it was not too bad.  We had to get an old school brass bushing machined to replace the pilot bearing and do some ghetto mods for the cross member.

He drives that thing up pass Dawson Creek from calgary once a month ... Looks like the motor will go before the tranny  !

[XJHERO]

We replaced the Peugeot out of XJHERO 88 Comanche with a 98 XJ AX15.


There were just a few challenges with the pilot bearing and the cross member but over all it was not too bad.  We had to get an old school brass bushing machined to replace the pilot bearing and do some ghetto mods for the cross member.

He drives that thing up pass Dawson Creek from calgary once a month ... Looks like the motor will go before the tranny  !

Oh ya I forgot we had to do all that, that whole weekend was a fury of jeep parts flying around and whiping drive shafts.

[Gearhead]

Hey all,

I have a 1988 Jeep XJ with the AX15 5 speed, the transmission has done fine for driving around town and the little bit of off roading I have been doing. Now that I am being a little more aggressive on the trails and tackling bigger obstacles I have gone though 4 now, and I am tired of it. I don't know much about them, so I am looking for some advice on a stronger transmission that will handle what I want to do with it. Any information would be awesome.

Thanks.

You sure it's an AX15  ?  ,  Peugeuot  trans were used until mid 89   , halfway through the year the AX15 was used in production as a running change.   Take a picture of the trans and post it  , so we can see if it is indeed an AX15 or not.