AX15 any good for my application?

AX15 any good for my application?

stoney bones

Active Jeeper
Posts
273
Media
4
Thanks
0
Location
michigan
Vehicle(s)
81 CJ7

258ci, mc2100 ,SR4 trans, dana 300 Tcase, dana 30 front, amc 20 2 piece rear
CJ7 , inline 6, currently 33" tires but wanting 35..

i was pretty dead set on getting a T-18 . but, given my application i need opinions on weather the ax15 might be a better match.

i dont want to hardcore wheel this rig. i want it to be DDable, but still comfortable on some mild trails. the T-18 1st is 6.32 the ax15 is 3.xx i honestly only see this thing going 4 x 4ing maybe 3 times a year.

your thoughts would be helpful
 
There would be a need to break down both trannys to install a new output shaft to mate to the 300. If I had to choose between the two I’d pick the T-18 .

Another option for your application would be a T-176 a direct bolt-in just have to adjust the driveshaft lengths.
 
whichever i pick i will be getting from novak. new and warrantied.

with a T-18 whats a comfy cruising speed on the highway in 4th?
 
There would be a need to break down both trannys to install a new output shaft to mate to the 300. If I had to choose between the two I’d pick the T-18 .

Another option for your application would be a T-176 a direct bolt-in just have to adjust the driveshaft lengths.

You dont need an output shaft to mate an ax-15, just a ring from novak or similar. Gives you an Overdrive as well!
 
Last edited:
I would say the ax15 for the OD and fully syncronized smoother shifting. My T-18 is a truck tranny through and through. An ax15 is more refined and the low first gear just annoys me for the street.
 
Need more info to recommend.

What axle ratio are you running?

Rule of thumb 4.10 for 33's, 4.56 for 35's
 
CJ7 , inline 6, currently 33" tires but wanting 35..

i was pretty dead set on getting a T-18 . but, given my application i need opinions on weather the ax15 might be a better match.

i dont want to hardcore wheel this rig. i want it to be DDable, but still comfortable on some mild trails. the T-18 1st is 6.32 the ax15 is 3.xx i honestly only see this thing going 4 x 4ing maybe 3 times a year.

your thoughts would be helpful

I think with the amount of offroading you plan, the AX15 might just be a better choice for you....given your Jeep will see more road time.
The T-18 is a truck tranny, and it acts like one. The AX15 is much more refined, cleaner shifting, and will give you a cruising gear.
 
I would say the ax15 for the OD and fully syncronized smoother shifting. My T-18 is a truck tranny through and through. An ax15 is more refined and the low first gear just annoys me for the street.
I didnt read your post Kane, but it looks like i pretty much copied it :D
 
Need more info to recommend.

What axle ratio are you running?

Rule of thumb 4.10 for 33's, 4.56 for 35's


not sure of the ratio but i plan on finding out...also, im on 33" so if you suggest the 4.10 does that take into consideration the application i have or is that ratio meant for off roading?



you guys got me leaning to the ax15 now. simply due to the over drive. i have found myself using the jeep more for longer distance runs and it would be nice to cruise comfy on the highway instead of taking back roads for longer trips...


as always, thanks for the advice
 
So did you ever do the ax15 swap? I also have an SR4 and found an ax15 close by for a few hundred bucks out of a 1999 with 40k miles. I heard its a pia swap? Have yet to find any write ups on the swap so I thought id ask.
 
My 2 Cents:

If you don’t plan to wheel but every now and then, stay with the 33s. You will get better gas mileage for your DD plus a CJ is more sensitive to rollover than a Wrangler of any flavor and lifting your CJ even more to fit the 35s only exacerbates the issue. To me a CJ should not be lifted more than 2-1/2” to 3”. If the plan is to cut up the body and do oversized axles and the like then please do us a favor and sell the CJ to someone who will preserve it and buy a YJ; there are so few decent CJs left. If it’s the look of a CJ you are after then put a CJ nose on the YJ; you can even put a CJ dash on a YJ too.

The T-18 is a great wheeling transmission however as stated it is a truck tranny and does drive like one but who cares. For the most part the swap can be done with OEM stock parts except for the adaptor required to fit the Dana 300 . But remember that not all T18s are 6.32:1 (wide ratio) as many are 4.0:1 (close ratio) and of course the wide ratio are the ones that are most sought after and command the highest price.

As far as using the CJ as a DD and off road too the T-18 may help. One option is to keep the differential gearing in the axles as high (numerically lower) as possible for best highway performance then drop a Teralow or Lomax kit (4:1) into the Dana 300 . The low transfer case coupled with the wide ratio T-18 should give you a fair crawl ratio for when you want to wheel but keep the rpm down when on the street.
 
Another great option is the 5 speed T-5 tranny. If you can find one. It came in a few CJ7s and is a direct bolt in. The AX 15 would be my second choice. It's what i have in mine and i like it.
 
So did you ever do the ax15 swap? I also have an SR4 and found an ax15 close by for a few hundred bucks out of a 1999 with 40k miles. I heard its a pia swap? Have yet to find any write ups on the swap so I thought id ask.

I've den the ax-15 swap on 2 YJ's with the AMC 258 i6 / 4.2l . (Same as a CJ4 .2) When people first started doing the swap the biggest pita was the pilot bearing. The ax-15 came with 2 different size input shaft tips. The small diameter from a internal slave will go right into the stock size pilot bearing, the bigger size from the external slave needs a special bearing that either Novak or advance adapters sells for less then $20 shipped. The next biggest issue is the clutch pedal and master cylinder. The easiest and best way to work this (if your jeep doesn't already have a hydraulic clutch) is to get a pedal assembly from a 87-89 yj. You want the brake and clutch pedal and bracket that bolts to the fire wall. The clutch pedal will also have an additional support that bolts through the fire wall to the clutch master. The 90 and up used a different bracket (I believe) that has a different spacing between the brake booster mounting holes.

For the over drive reliability of a Ax-15 it's definitely worth the modifications.
Oh and the Dana 300 will bolt directly to the ax-15 but needs to be clocked up for clearance. No need to change output gears.
 
4:10s with 35s works fine on the street but a little tall on the trail. When I swapped In the auto aw4 the 410 were much better.

Sent from my Galaxy S3 with Taptalk 2
 
The AX15 is the strongest tranny ever put into a Jeep by the factory, it is a great tranny, if you have the room go for it by all means.
going over 33s on a cj is going mean special treatment and cutting to make it work properly.
I owned a TJ and never went over 33s and wheeled with guys running 37s all the time, a lot of that is hype and lot of it is using tires to mke up for a lack of skills, believe me 33s can conquer the rubicon with ease, I take my CJ5 over it on 31s and have no dents in the body.
 
Ax15 was not the strongest oem trans. T-18 and T-98 were way stronger. These were the heavy duty offering. Ax15 is a med duty.



Sent from my Galaxy S3 with Taptalk 2
 
I've den the ax-15 swap on 2 YJ's with the AMC 258 i6 / 4.2l . (Same as a CJ4 .2) When people first started doing the swap the biggest pita was the pilot bearing. The ax-15 came with 2 different size input shaft tips. The small diameter from a internal slave will go right into the stock size pilot bearing, the bigger size from the external slave needs a special bearing that either Novak or advance adapters sells for less then $20 shipped. The next biggest issue is the clutch pedal and master cylinder. The easiest and best way to work this (if your jeep doesn't already have a hydraulic clutch) is to get a pedal assembly from a 87-89 yj. You want the brake and clutch pedal and bracket that bolts to the fire wall. The clutch pedal will also have an additional support that bolts through the fire wall to the clutch master. The 90 and up used a different bracket (I believe) that has a different spacing between the brake booster mounting holes.
For the over drive reliability of a Ax-15 it's definitely worth the modifications.
Oh and the Dana 300 will bolt directly to the ax-15 but needs to be clocked up for clearance. No need to change output gears.
Is there no way to make the mechanical clutch work? Maybe a stupid question, since if there was someone would have already done it. Or is it just easier? I ask cause I have thought about this and the T-176 and AX-15 are close in gear ratio, strength plus has the AX-15 has od. I have 4.10 in my axles and turn 2800rpm at 70mph. Would be nice to have od. on the highway. Would shorter driveshaft for the rear and longer for the front be needed?
 
Last edited:
Is there no way to make the mechanical clutch work? Maybe a stupid question, since if there was someone would have already done it. Or is it just easier? I ask cause I have thought about this and the T-176 and AX-15 are close in gear ratio, strength plus has the AX-15 has od. I have 4.10 in my axles and turn 2800rpm at 70mph. Would be nice to have od. on the highway. Would shorter driveshaft for the rear and longer for the front be needed?

Yes there is a way. Advance adapters sells a kit that allows you to mate an AX15 to a T-176 bellhousing. This would allow you to retain the mechanical clutch.

That being said if you were to swtich to an ax15 I would join jimbo and say that you should also swap to a hydraulic clutch and go through the process of swapping in the yj pedal bracket assembly. It is not too hard to do as the yj assembly will directly bolt in place of the cj assembly. Doing this will give you smooth clutch operation and would really compliment the newer tranny.
 
watch what year you get of the AX15, a internal hydraulic slave is a bit problematic, make sure you get the outside one.
I think you are going be amazed by the tranny, I have put it under a few Jeeps and never have had a problem with it. Have ripped out a few NV3550s to put in AX15s, they are great tranny.
 
Ax15 was not the strongest oem trans. T-18 and T-98 were way stronger. These were the heavy duty offering. Ax15 is a med duty.



Sent from my Galaxy S3 with Taptalk 2
go for your ratings, on the rocks I will take a AX15 any day. we can talk ratings all day but will we be discussing something that has changed like HP ratings from the 60e to HP ratings today?
 

Jeep-CJ Donation Drive

Help support Jeep-CJ.com by making a donation.

Help support Jeep-CJ.com by making a donation.
Goal
$200.00
Earned
$85.00
This donation drive ends in
Back
Top Bottom