Any 4-speed manual experience here?

GASnBRASS

TJ Enthusiast
Joined
Apr 6, 2017
Messages
688
Location
Minnesota
Any experience with a 4spd manual trans swap in a TJ with a deep granny 1st gear?
Other option is an AX15, but I don't think overdrive would be ideal with 4.10 gears/33" tires, unless someone says otherwise.
 
Last edited by a moderator:
  • Like
Reactions: TJTJ04
Why on earth would you want a 4 speed?

Depending on the year, should be a 5 or 6 speed. I have an 06 and it was 6 speed (I swapped to auto). I have a friend that prefers the 5 speed.

In order to get it working, you'll need everything from the donor vehicle - Trans, computer, wiring harness, etc.
 
  • Like
Reactions: Chris
I too am confused as to why you’d want a 4-speed. Seems like a downgrade to me.
 
Any experience with a 4spd manual trans swap in a TJ with a deep granny 1st gear?
Other option is an AX15, but I don't think overdrive would be ideal with 4.10 gears/33" tires, unless someone says otherwise.

I dont think they ever put a 4 speed manual in any TJ or even YJ ! maybe a CJ !
 
*sigh*

Of course jeep never put a 4 speed manual in the TJ.

My current 4.10 gears and 33"s would make 5th gear useless.

Some 4 speeds have a granny 1st gear of 4.5:1 or 6.5:1, deeper than the AX15's 3.8:1
 
  • Like
Reactions: tr21triton
*sigh*

Of course jeep never put a 4 speed manual in the TJ.

My current 4.10 gears and 33"s would make 5th gear useless.

Some 4 speeds have a granny 1st gear of 4.5:1 or 6.5:1, deeper than the AX15's 3.8:1

by the time you go through all that trouble it would probably be cheaper to just regear it !
 
  • Like
Reactions: L J
Might be kinda cool 35s. I think the highway gearing would be a little deep for my tastes with 33s. I would love a deeper first gear, especially with my ax15 swap...I enjoyed the nsg370 first.

Poke around on advance adapters and see what you can find, I'm pretty sure they make a bellhousing for a sm465 or something into a 4.0. you'll end up needing two new driveshafts, a transfer case that bolts up, a custom trans mount,figure out the t case shifter situation, and probably want to look into the height of the box to make sure there's enough space in the tunnel.

All in all I think there are more cost and labor effective ways to get your 5th gear back and a better crawl ratio.
 
ya know another idea would be you could find a old bronco (66-77) remove the body, cut the frame to accept your TJ body. you'd have a 302 v8, 3 speed and dana 44's ! what more could you ask for ? BOY THAT WAS EASY !
 
*sigh*

Of course jeep never put a 4 speed manual in the TJ.

My current 4.10 gears and 33"s would make 5th gear useless.

Some 4 speeds have a granny 1st gear of 4.5:1 or 6.5:1, deeper than the AX15's 3.8:1

The math works , don't let folks who likely never owned a truck 4 spd. discourage you. build what works for YOU.
Maybe install a 8- track player just to give some prospective!:LOL:
 
I think some of these guys have never driven a truck with a granny first gear. My buddy had a J20 with one. I loved driving it around the farm. Crawling in low low was too much fun
 
Any experience with a 4spd manual trans swap in a TJ with a deep granny 1st gear?
Other option is an AX15, but I don't think overdrive would be ideal with 4.10 gears/33" tires, unless someone says otherwise.

What about the TR 4050 TREMEC. It’s a modern transmission with low first. Has a big price tag
 
AA bellhousing adapters are available for the NP435 and SM465, but I see Novak is dropping the NP435 trans in favor of the T18. Wasn't sure where the shifter would end up, but under the dash would be a pain to make work.

I did see that Tremec 5 speed with 6:1 granny first and an overdrive gear with 242 bellhousing. Direct boltup to NP T-case. Shifter appears further back, but it ain't a cheap setup. If my gearing was better suited for it I'd say 'eff it and just go that route.

Tired of farking around with this 32rh. Maybe I'll try swapping in the RMVB I've got sitting on the shelf first.
 
  • Like
Reactions: GPK03X