AX15 or NV3550 behind AMC V8 looking for real world success vs. failure experience
- Thread starter Scott_P
- Start date
- City
- West Bend
- State
- WI
Crap, I wish I saw this sooner. I have the adapter you just bought that I was going to put up for sale. As far as the clocking rings go, the ax15 requires it because of the length of the output shaft. The adapter put it at the correct length and was only like $40 new on eBay. The nv has a shorter output shaft. I don't know about the nv, but I do know that on the ax15 the output shaft seal for a Wrangler will not work. You have to use one for a 1994 dodge Dakota v6. Some claim you need to use some fancy double lip seal and I can tell you first hand that's not true.
Update, trans swap is going smoothly! (so far...) I ended up going with a Novak Adapter to retain the factory AMC V8 bellhousing, clutch, linkage, etc. It was a bit of work to get the right one, but Novak was very responsive and once I had the right parts (NV3550 vs. AX15 adapter) it all went together rather smoothly.
Now for the finishing details...anybody have a recommendation on a clean looking shift lever boot?
I also twin sticked my D300 while doing this swap, thinking about using the JB Custom twin stick boot and bezel for this one.
Anyhow looking for any ideas or recommendations, thanks!
Now for the finishing details...anybody have a recommendation on a clean looking shift lever boot?
I also twin sticked my D300 while doing this swap, thinking about using the JB Custom twin stick boot and bezel for this one.
Anyhow looking for any ideas or recommendations, thanks!
whitenite97
Legacy Registered User
- City
- Baton Rouge
- State
- LA
I really wanted to upgrade to a 5 sp but just repaired the T-176. Regretting that after reading this. Thanks
I did JB twin stick to my dana while I was there and went with the Stonghold Shiftboot. Looks great and quality seems great, but haven't had it very long. I just got tired of the old ones ripping.
https://www.strongholdshiftboots.com/
I did JB twin stick to my dana while I was there and went with the Stonghold Shiftboot. Looks great and quality seems great, but haven't had it very long. I just got tired of the old ones ripping.
https://www.strongholdshiftboots.com/
- City
- Biloxi
- State
- MS
I never replied to your thread, mainly because you are using an AMC V8, but here goes:
I purchased a "Japanese Medium Duty truck" AX15 from Novak brand new. I did this because I did not like how "high" the first gear ratio of the Jeep AX15's are. The transmission I have has ratio's similar to a T5, i.e a 4:1 first gear. IIRC, the NV3500 has a similar 4:1 first gear. I originally was going to swap in an NV transmission because of the first gear ratio, but there are AX15 variant's that have deeper first gear ratio's then the Jeep version out there, but might be hard to find
I used a T176/T150 bell housing, and all of my stock mechanical clutch linkage. I used the Novak adapter plate that bolts to the face of the transmission to adapt the AX15 to the stock CJ bell housing, the Novak spacer/adapter/clocking ring to bolt the Dana 300 to the back of the AX15.
I was able to use a stock CJ transmission mount/torque arm, used the stock skid plate in the T5/T4 position, just had to drill three new holes in the skid plate.
I had to heat/bend the AX15 shifter just a hair to clear my Tuffy console's front mounted cup holders: I am using a stock T5 cover plate, T5 shifter boot, works fine.
On the Dana 300's shifter, I used a 1980/1981 Dana 300 shifter that is really long. I was able to heat it, bend it, it too comes through the stock Dana 300 shifter hole in the stock T5 cover plate. Both shifters look factory.
Since the AX15 was longer then the three blown up T5's it replaced, I had a shorter rear/longer front driveshafts made.
My AX15 was behind my 258 that had Hesco fuel injection, worked perfectly. It is now behind a 4.0 with the same Hesco fuel injection, works fine here, too. I do not have the power/torque of a V8, but I would think the transmission would hold up to a V8 with "moderate" use, i.e. no drag racing high RPM clutch dumps
I don't "baby" my red Scrambler, don't beat the $hit out of it either, and the AX15 has held up fine so far 
As for fluid, just as much controversy with the AX15's as the T5's
I use NAPA MTL fluid, thicker than ATF, thinner then gear oil. Seems to work fine, transmission shifts easy, no knotchy feelings. My transmission survived a drive from south MS to Moab, a week of wheeling there, and the drive back home with this fluid and it did not explode, so I would assume it is the "correct fluid"
All in all, I am happy with the Novak AX15 and all the parts I purchased from Novak, good customer support. So far so good
I have a bunch of pictures/info on my red Scrambler build thread, around Post #1195:
https://www.cj-8.com/forum/showthre...ATE-BODY-ON-FRAME-AGAIN/page80&highlight=AX15
I purchased a "Japanese Medium Duty truck" AX15 from Novak brand new. I did this because I did not like how "high" the first gear ratio of the Jeep AX15's are. The transmission I have has ratio's similar to a T5, i.e a 4:1 first gear. IIRC, the NV3500 has a similar 4:1 first gear. I originally was going to swap in an NV transmission because of the first gear ratio, but there are AX15 variant's that have deeper first gear ratio's then the Jeep version out there, but might be hard to find
I used a T176/T150 bell housing, and all of my stock mechanical clutch linkage. I used the Novak adapter plate that bolts to the face of the transmission to adapt the AX15 to the stock CJ bell housing, the Novak spacer/adapter/clocking ring to bolt the Dana 300 to the back of the AX15.
I was able to use a stock CJ transmission mount/torque arm, used the stock skid plate in the T5/T4 position, just had to drill three new holes in the skid plate.
I had to heat/bend the AX15 shifter just a hair to clear my Tuffy console's front mounted cup holders: I am using a stock T5 cover plate, T5 shifter boot, works fine.
On the Dana 300's shifter, I used a 1980/1981 Dana 300 shifter that is really long. I was able to heat it, bend it, it too comes through the stock Dana 300 shifter hole in the stock T5 cover plate. Both shifters look factory.
Since the AX15 was longer then the three blown up T5's it replaced, I had a shorter rear/longer front driveshafts made.
My AX15 was behind my 258 that had Hesco fuel injection, worked perfectly. It is now behind a 4.0 with the same Hesco fuel injection, works fine here, too. I do not have the power/torque of a V8, but I would think the transmission would hold up to a V8 with "moderate" use, i.e. no drag racing high RPM clutch dumps
I don't "baby" my red Scrambler, don't beat the $hit out of it either, and the AX15 has held up fine so far As for fluid, just as much controversy with the AX15's as the T5's
I use NAPA MTL fluid, thicker than ATF, thinner then gear oil. Seems to work fine, transmission shifts easy, no knotchy feelings. My transmission survived a drive from south MS to Moab, a week of wheeling there, and the drive back home with this fluid and it did not explode, so I would assume it is the "correct fluid" All in all, I am happy with the Novak AX15 and all the parts I purchased from Novak, good customer support. So far so good
I have a bunch of pictures/info on my red Scrambler build thread, around Post #1195:
https://www.cj-8.com/forum/showthre...ATE-BODY-ON-FRAME-AGAIN/page80&highlight=AX15
Last edited:
spankrjs: sounds like a nice build!
While not completely finished (still have shifter boots), mechanically I am about done. Drove it sunday night and everything seems fine, but it was late, dark and just a quick spin. I plan to list some detail of my set-up soon....been caught with the flu this week.
While not completely finished (still have shifter boots), mechanically I am about done. Drove it sunday night and everything seems fine, but it was late, dark and just a quick spin. I plan to list some detail of my set-up soon....been caught with the flu this week.
BW - Thanks! I very rarily get sick...first time in years and it has been the death flu...feeling much better now.
Here's a quick outline of my near final set-up swapping out a T-176 for the NV3550:
1. The NV3550 is mated to the AMC V-8 bellhousing and retaining factory clutch linkage using a Novak Adapter - I went this route to keep my firewall clean and it would have been tight to fit a hydraulic master cylinder. Otherwise I could have made the swap with the factory Jeep NV3550 bellhousing and no adapter at all. If I were doing a new build, I would have gone this route. (Note, I have a fiberglass tub that the previous owner installed fuse block, steering, pedal assembly, etc....done nicely. It's always a pain to cut new holes in nice paint, etc.) You have to drill a clearance hole in the face of the bellhousing for the shift rail boss on the front of the NV3550, not big deal with a hole saw. NOTE: The instructions were not very clear, but I had to clearance the top bellhousing bolt holes to bolt the bellhousing to the adapter from inside the bellhousing (I think the website briefly mentions this, but not in instructions.) I also had to clearance the bottom 2 adapter holes to bolt to the bellhousing...hated to drill out threads in a $320 adapter!
2. The Dana 300 bolts direct to the XJ NV3550, no clocking ring necessary for factory position
3. The NV3550 w/adapter is about a 5" longer set-up. I moved the cross member from the forward set of frame holes to the rearward set. Fell in the perfect position.
4. I re-used the factory torque arm trans mount. To do so I took a piece of 3/8" plate and with countersunk cap screws bolted it to the NV3550. Then in the proper spot bolted the factory mount to the 3/8" plate by tapping a couple holes. In the end the factory mount re-used one of the factory sets of hole in the cross member. Clean set-up.
5. Front and rear driveshafts were lengthed & shortened respectively.
6. In my case I had to modify exhaust a little
7. Speedometer cable, transfer case 4wd indicator light wire and breather tube all had enough length to hook back up with a little re-routing.
8. Wildhorses 4x4 provides a pigtail connector for the factory reverse light switch on the NV3550. Quite pricey, but easier to buy than trying to find one in the junkyard under 3' of snow in January.
9. I choose to twin stick my Dana 300 at this time. I used an Omix-Ada kit that I found locally on Craig's List brand new for a deal. One nice thing is the ability to move the lever pivot points fore/aft for your particular set-up/taste. I used the middle location. I did re-bend the levers to get a cleaner look and remedy interference with the NV3550 lever (also slightly re-bent) when in 5th or reverse gears. You can use the factory Dana 300 lever with some mild trimming of a rib on the NV3550 case. Another Twin stick option is JB Customs...looks like nice stuff, but by the time I discovered them, I already had my Craig's List deal.
10. Novak makes a nice aluminum floor pan hump cover blank to cover it all up. I went with it for the ease, and made my own new holes for the new set-up. I suppose if you had an automatic parts jeep you could grab that one, or weld patches in the old one.
11. Still working the shift boots....illness delay!
Will try to post some pictures soon. Re-world feedback on performance will have to wait until the salt is gone...sorry. All in all a pretty easy swap and interesting to see how little you have to modify/how much you can reuse factory positions/holes, etc.
Here's a quick outline of my near final set-up swapping out a T-176 for the NV3550:
1. The NV3550 is mated to the AMC V-8 bellhousing and retaining factory clutch linkage using a Novak Adapter - I went this route to keep my firewall clean and it would have been tight to fit a hydraulic master cylinder. Otherwise I could have made the swap with the factory Jeep NV3550 bellhousing and no adapter at all. If I were doing a new build, I would have gone this route. (Note, I have a fiberglass tub that the previous owner installed fuse block, steering, pedal assembly, etc....done nicely. It's always a pain to cut new holes in nice paint, etc.) You have to drill a clearance hole in the face of the bellhousing for the shift rail boss on the front of the NV3550, not big deal with a hole saw. NOTE: The instructions were not very clear, but I had to clearance the top bellhousing bolt holes to bolt the bellhousing to the adapter from inside the bellhousing (I think the website briefly mentions this, but not in instructions.) I also had to clearance the bottom 2 adapter holes to bolt to the bellhousing...hated to drill out threads in a $320 adapter!
2. The Dana 300 bolts direct to the XJ NV3550, no clocking ring necessary for factory position
3. The NV3550 w/adapter is about a 5" longer set-up. I moved the cross member from the forward set of frame holes to the rearward set. Fell in the perfect position.
4. I re-used the factory torque arm trans mount. To do so I took a piece of 3/8" plate and with countersunk cap screws bolted it to the NV3550. Then in the proper spot bolted the factory mount to the 3/8" plate by tapping a couple holes. In the end the factory mount re-used one of the factory sets of hole in the cross member. Clean set-up.
5. Front and rear driveshafts were lengthed & shortened respectively.
6. In my case I had to modify exhaust a little
7. Speedometer cable, transfer case 4wd indicator light wire and breather tube all had enough length to hook back up with a little re-routing.
8. Wildhorses 4x4 provides a pigtail connector for the factory reverse light switch on the NV3550. Quite pricey, but easier to buy than trying to find one in the junkyard under 3' of snow in January.
9. I choose to twin stick my Dana 300 at this time. I used an Omix-Ada kit that I found locally on Craig's List brand new for a deal. One nice thing is the ability to move the lever pivot points fore/aft for your particular set-up/taste. I used the middle location. I did re-bend the levers to get a cleaner look and remedy interference with the NV3550 lever (also slightly re-bent) when in 5th or reverse gears. You can use the factory Dana 300 lever with some mild trimming of a rib on the NV3550 case. Another Twin stick option is JB Customs...looks like nice stuff, but by the time I discovered them, I already had my Craig's List deal.
10. Novak makes a nice aluminum floor pan hump cover blank to cover it all up. I went with it for the ease, and made my own new holes for the new set-up. I suppose if you had an automatic parts jeep you could grab that one, or weld patches in the old one.
11. Still working the shift boots....illness delay!
Will try to post some pictures soon. Re-world feedback on performance will have to wait until the salt is gone...sorry. All in all a pretty easy swap and interesting to see how little you have to modify/how much you can reuse factory positions/holes, etc.
One other step I forgot to mention above....the Novak adapter requires you to cut the nose off the NV3550 front bearing retainer. Not a big deal...razor wheel in a 4-1/2" grinder makes quick work of it. the adapter comes with a new bearing retainer that looks identical to the T-176.
- City
- Columbia
- State
- MO
This is a great thread! I've been debating the AX15 vs. NV3550 for a while now. I had pretty much settled on the NV3550 but they are harder to find then the AX15. I guess it will just depend on which one I find for a good deal. Saving this thread for all the good info!
Thanks, I will keep updating as I finish the details and judge outcome. Unfortunately, been too busy with family stuff to get back on it! Ski team has been taking all my time and a few repairs on my daughters XJ....weird thing happened this week...vibration dampener started coming apart, noticed the belt walking on the mech fan sheave.
Hi Guys,
Love this forum. I have a 1985 Jeep CJ-7 with AMC 304 with a T5 Tranny. I am thinking of putting an AMC 401 in it. I don't do rock crawling. I use it on the street and do some mild to medium off roading. What tranny should I go for? I prefer a 5 speed manual transmission. Any input is appreciated. Thank you
Love this forum. I have a 1985 Jeep CJ-7 with AMC 304 with a T5 Tranny. I am thinking of putting an AMC 401 in it. I don't do rock crawling. I use it on the street and do some mild to medium off roading. What tranny should I go for? I prefer a 5 speed manual transmission. Any input is appreciated. Thank you
Kane
CJ-8 Member
- City
- Berlin
- State
- ct
The AX15 will be fine for you. They are rated at 300ft/lbs of input torque but that is conservative as they have been known to handle more than that. I have the AX15 in my Jeep and love it. The conversion cost was 100% worth it.