Transmission swap from TF727 to a manual

[Crossfit_Wagon]

Hello all you smart people. I am planning on swapping my TF727 in my 84. I am wanting to go with a 5 speed. I am looking at the NV4500 or the AX15. I am sure someone can chime in on what they have seen done. I have the stock NP229 T case and it can go to if that is the best thing to do. What T case do I go with if I pull it? It's a drivers side drop. I am looking at the info on Novak's website. It looks like the AX15 will be much cheaper but will it be the right way to go. Is there a tranny/t case combo that will bolt right or one that will require minimal adapter parts?

It will go behind a rebuilt 401 as well that will have around 400-450HP. Thanks for everyones help. I am a newbie and not much of a wrench guy so this is all new for me. I am having the work done by a friend who has been building FSJ's for a long time.

Thanks,
Robbie

[Mex in the city]

http://www.ifsja.org/forums/vb/showthread.php?t=154895

[Crossfit_Wagon]

http://www.ifsja.org/forums/vb/showthread.php?t=154895

Thanks, I read this and this is what gave me the idea of the AX15.

[Carnuck]

AX-15 and 401 is a no-go as far as I'm concerned. It will work, but won't take punishment. T5 is far worse though. Barely enough for the 258. If you find any Jeep 4.0L with 4500, 5500 then it will be better. I don't know about the length for fitment, but I put an AX-15 with NP208 in my '83 J10.

[JeepsAndGuns]

If your running a 401 with that much HP, I would skip the AX-15. The NV4500 is going to be your better choice.
The AX15 is a good trans and can take some abuse, but that much HP is over its rated capicity. Add that to a already heavy vehicle, and the trans will be short lived. The NV4500 is going to be more expensive, but the better and stronger choice in the long run.
If you could find a gas dodge version with a 23 spline output, most dodge/jeep NP transfer cases would bolt to it pretty easy. Then you could get a advance adapters plate to use a stock jeep bellhousing.
If you find a chevy version with a 32 spline output, you could run a chevy NP241 transfer case. You could then either get a full conversion bellhousing, or swap in a dodge input shaft and then be able to run a adapter plate and a jeep bellhousing.

[Crossfit_Wagon]

If your running a 401 with that much HP, I would skip the AX-15. The NV4500 is going to be your better choice.
The AX15 is a good trans and can take some abuse, but that much HP is over its rated capicity. Add that to a already heavy vehicle, and the trans will be short lived. The NV4500 is going to be more expensive, but the better and stronger choice in the long run.
If you could find a gas dodge version with a 23 spline output, most dodge/jeep NP transfer cases would bolt to it pretty easy. Then you could get a advance adapters plate to use a stock jeep bellhousing.
If you find a chevy version with a 32 spline output, you could run a chevy NP241 transfer case. You could then either get a full conversion bellhousing, or swap in a dodge input shaft and then be able to run a adapter plate and a jeep bellhousing.

What about the T18? I already have one and not using it. Just wasn't sure if I would miss that 5th gear and would regret not going with the NV4500?

[Ristow]

the T18 has horrible gear spacing and shifts like it belongs in an 18 wheeler.

nv4500 has a better shift but the same crappy ratios up to 4th gear.

you have a wagon? what gears in the axles.

also. what has been done to this 401? i ask because the 401 has been blown a bit out of proportion,and a fair amount of people seem to think their mighty 4-oh-1 makes 400+ hp because they put a 4 barrel on it,and it's simply not true. here a dyno run on a mild build with increased compression.

http://www.ifsja.org/forums/vb/showpost.php?p=1498687&postcount=184

if you have a stock shortblock,and take it relatively easy the ax15 would survive,and be much nicer to drive.

if this is a mostly street driven car,no way would i recommend the T18. i'd be hesistant of the nv4500 too.

[Crossfit_Wagon]

the T18 has horrible gear spacing and shifts like it belongs in an 18 wheeler.

nv4500 has a better shift but the same crappy ratios up to 4th gear.

you have a wagon? what gears in the axles.

also. what has been done to this 401? i ask because the 401 has been blown a bit out of proportion,and a fair amount of people seem to think their mighty 4-oh-1 makes 400+ hp because they put a 4 barrel on it,and it's simply not true. here a dyno run on a mild build with increased compression.

http://www.ifsja.org/forums/vb/showpost.php?p=1498687&postcount=184

if you have a stock shortblock,and take it relatively easy the ax15 would survive,and be much nicer to drive.

if this is a mostly street driven car,no way would i recommend the T18. i'd be hesistant of the nv4500 too.

Pretty similar built but 40 over, Harland roller rockers, Howell TBI and a few other things. I definitely don't want an 18 wheeler shifting rig.

[Ristow]

id re-look at the ax15. you are nowhere near 400 horse.

[addicted]

The NV3550 is another option. Supposed to be stronger than the AX-15 and it was also found behind the 4.0. They are harder to find and cost more because of it.

[Ristow]

a good alternative too. thanks simon.

[Carnuck]

I was talking to someone yesterday who said there were new 3550s available online for @$1500

[Carnuck]

id re-look at the ax15. you are nowhere near 400 horse.

Everyone talks HP when torque is what you need to worry about. The input shaft can handle only so much before it twists off and the stroker 6 cyls in lighter XJs and TJs tax them and kill them frequently.

[Ristow]

horsepower and torque go hand in hand. in a given rpm increase horsepower you increased torque. hp is the term people use.

sure you break it if you want with a i6. aint saying he wouldnt need to be careful.

[babywag]

Everyone talks HP when torque is what you need to worry about. The input shaft can handle only so much before it twists off and the stroker 6 cyls in lighter XJs and TJs tax them and kill them frequently.

Torque vs. HP is just math...just different "terms/values".
Most dyno systems measure in torque and calculate the HP from that.

One is not more important than the other. Just depends on what limits you have to work with.