AX5 upgrades - replacement

StG58

StG58

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So us poor buggers with the TJ SE's are living with a marginal manual transmission. The AX5 has an evil reputation in the TJ when you go with bigger tires and use it off road. Heck, it has an evil reputation just tooling along to the mall on stock tires.

So, what's the consensus and what are some ideas on things that we can do with our AX5's to get them to down shift more smoothly, live longer and take a bit more abuse?

I ran across an NV4500 transmission swap kit for putting an NV4500 out of Dodge and GM trucks into a TJ, but further research showed that to have some issues.

What'cha all got for ideas?
 
As long as you AX5 is performing ok why not just stay with it. I've been running 31's on mine without any issues. There is the option of swapping in the AX15 and there are write-up on that.
 
TJ4Jim said:
As long as you AX5 is performing ok why not just stay with it. I've been running 31's on mine without any issues. There is the option of swapping in the AX15 and there are write-up on that.
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It's performing it's function of tranferring power just fine right now, but it's irritating me to no end with the notchy upshifts and the blipping throttle on downshifts. The synchro's are getting weak in mine, I think, and it is getting closer to rebuild / replacement time.

The AX15 swap is viable, but rounding up the parts can be a pain in the backside.
 
That would be annoying. Cannot really complain about mine, uninstalled a short throw shifter in it last year and I love it. Beyond that there's not much available to upgrade the AX5.

What size tires are you looking to run in the future as that may force you to swap out the gears in the diff also
 
31 - 32" tires. Got the axles all planned out, and in the budget. Still waffling between 31x10.50R15's and 265/75R16's though.

I'm keeping the Jeep low, narrow and light. That works best for what I do.

The stealership that had this TJ for sale sold new Subarus, and did a land office business. Actually had some really nice used cars for sale. Mine was a trade in, and they did their usual pre-sale maintenance program to it, that included changing out the gear oil in the transmission and differentials. Guess what. They didn't have a clue about Jeep transmissions and put their usual GL5 oil in it. I put several thousand miles on it after I got it before I figured it out. That was one smooth shifting transmission when it went out for the test drive, not so much after I got it home and drove it for a bit.

Pretty sure that a set of new brass parts would fix it right up, but if I'm going in there, it would be nice to do any upgrades possible while it's apart.
 
I would recommend that you change out the trans fluid to Redline and see what happens, I love the stuff. I'm running 31's now and she has performed well with that size tire and the 4:10 axle.
 
I started using Redline in my wife's TR6 4 speed trans and the results were startling, then when I bought the Wrangler a while back I changed the fluid out in the AX5 right away and that was before I found out that many swear by it. I call it the "re-build in a can".
Summit is a good source as it's usually not available locally.
 
,I had the NV 4500 in my 95 YJ. Would really like to have it in Stinger now. Don't want to start the whole auto vs manual crap. I LIKED my 4500.. That being said. My 98 Dodge pickup had a 4500 and it was quite, my jeep had an unknown breed 4500 and it was noisy!
I would do the 4500 in my rig right now, except this particular engine and is not really happy with a manual. So I have been told by " experts. "
 
StG58 said:
I ran across an NV4500 transmission swap kit for putting an NV4500 out of Dodge and GM trucks into a TJ, but further research showed that to have some issues.
Click to expand...

Stinger said:
,I had the NV 4500 in my 95 YJ. Would really like to have it in Stinger now. Don't want to start the whole auto vs manual crap. I LIKED my 4500.. That being said. My 98 Dodge pickup had a 4500 and it was quite, my jeep had an unknown breed 4500 and it was noisy!
Click to expand...

I have an NV4500 in my CJ-7 and it is rock solid. I know they have a reputation for having issues with 5th gear but those are only when run under load in heavy duty trucks. As far as noise, I can't hear anything in my CJ anyways :p
 
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Yup, the NV4500 has a good reputation as an upgrade. Every build that I've read about says the same thing though. Plugging one into a TJ is pretty straight forward, but they are a BIG transmission. There are tunnel mods that need to happen to make it fit as it is much taller installed than the AX5 and the AX15. With the stock belly pan, there is some cutting around the shift tower to make it fit. With a tummy tuck, there is a huge amount of tunnel mods to be made.

The AX15 and the NV3550 look like a much better swap, as kits are available that are almost plug and play.
 
StG58 said:
The AX15 swap is viable, but rounding up the parts can be a pain in the backside.
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What is such a pain in the A$$ about rounding up the parts? Just find an AX15 and then a Dakota bellhousing and you're good to go. Junkyards have the AX15 and I'm sure you can find the Dakota bellhousing there too.
 
Wildman said:
What is such a pain in the A$$ about rounding up the parts? Just find an AX15 and then a Dakota bellhousing and you're good to go. Junkyards have the AX15 and I'm sure you can find the Dakota bellhousing there too.
Click to expand...
One man's excellent adventure is another man's pain in the ass. There is more to plugging in an AX15 behind a 2.5 liter than just a transmission and a bell housing.
 
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