3- speed?

[archer2147]

Would it be worth putting a 4 or 5 speed in a ol 75 CJ5 ? i dont do a lot of highway driving, which is damn near impossible in that thing, but hey, i gotta get to where im going you know? Its a fairly new tranny, but im thinkin upgrade so im not winding out so hard.... maybe new gears?? any suggestions are appreciated.. thanks again

 

[LongHorn]

What kind of off-road driving do you do?

 

[Kane]

3 speed to 4 speed is no different for highway driving since they both have a top gear of 1-1. The 5 speed is a better choice but a very tough (but doable) fit into a CJ5 . If you have 35 inch tires like your profile then you most likely have allot of lift and that will not help with you driveshaft anlges and a 5 speed. It sound like your only other option is a regear for lower RPMs.

 

[archer2147]

i dont do a lot of off-roading, but when i do its just dirt/mud roads, snow trails. i may look into re-gearing....

 

[JR74CJ5]

I run 4.27 gearing with 33 tires. I run 65-70+ no problems with my T-15 3 speed.

 

[archer2147]

then thats what ill do, thanks again

 

[LongHorn]

i dont do a lot of off-roading, but when i do its just dirt/mud roads, snow trails. i may look into re-gearing....

I run a T-19a 4-speed, with a 6.32 to 1 low.
It's shorter than a 5-speed & a hell of a lot stronger.
In reality it has a wider ratio spread than most 5 speeds.
Most 5 speeds run a 1st. gear in the 3 to 1 range with a .70 O/D.
My rig is only doing 2800rpm at 70mph, same as my old 280Z 5 speed.
You maybe able to get away with just a Transmission swap, instead of spending money on regearing & a Transmission swap.

 

[JR74CJ5]

I run a T-19a 4-speed, with a 6.32 to 1 low.
It's shorter than a 5-speed & a hell of a lot stronger.
In reality it has a wider ratio spread than most 5 speeds.
Most 5 speeds run a 1st. gear in the 3 to 1 range with a .70 O/D.
My rig is only doing 2800rpm at 70mph, same as my old 280Z 5 speed.
You maybe able to get away with just a Transmission swap, instead of spending money on regearing & a Transmission swap.

All true...

Archer, what gearing and tranny are you currently running?

I seen your post saying the tranny was pretty new, so didn't think you'd be swapping it if you didn't have to. The T-18 Longhorn mentions is a awesome tranny... I couldn't afford the swap yet...:drool:

But If you know the gearing and tranny you have let us know.

I still think if there's nothing wrong with the tranny, it would be cheaper all around to just change the gearing, although you are looking at about $300.00ea (approx) for the ring and pinion for front and back, and more if you are not going to do it yourself... So it may be possible to get the tranny swap for less if you're lucky and patient...

Either way, I was just mentioning in my first post to assure you you can achieve freeway speed at a comfortable RPM with a 3 speed tranny. My gearing may not be the best for off road though (haven't tested it out much yet) but I think I'll achieve that in the T case or Tranny swap later, for now I love the 4.27 gearing on the highway, but it does seem that that ratio is pretty uncommon.

(Also) Note you have larger tires than me, so you may want to look at a different ratio... One that will work better with your tire size...
Either way and let us know what you decide / do.

~ JR

 

[47guy]

I am running a 79 CJ5 with the T-150 three speed. I have 35s and am running the original AMC20 with the 3.55 gears it will run 80 (and scare you to death as it becomes unstable at 65) on the highway but I usually keep it below 60. As far as off-road I have the AMC 258 i6 / 4.2l and there is no need at all to change gears or trany it will dig and pull anyhwere any time. If I remeber right Yukon gear has a gear ratio to tire size chart if you are running 35s a set of 4.55 gears will put you at factory original performance (Speedo reading, takeoff, RPM to MPH) but as the number gets bigger takeoff power gets better and speeds get slower. The only problem I have with the factory gears and the three speed with the big tires is the speedometer is about 15 mph off and I forget some times.

 

[archer2147]

well i gotta get my speedo working first, lol... and im not sure what tranny is under it, but i may just do a gear swap right now, ill keep yall updated...