AimTime

so there isn't a way to give 1/4th more torque than 5.13's give to a 37? I'd love for gear 4 to be at 3,000rpm at 70. From what I've seen I'm limited to my super 60 front, 5.38 is the highest gear size I've seen for it.
My idea for the rubicrawler would be to run it from 1-4 then shift back into high gears and go to 3-4.

TheDirtman

No, personally I would not go more then a 35" tire on the 3.8 with the auto and would still go with 5.38 gears.

AimTime

So if it was a 6 speed you'd run 40's on 5.38's?

TheDirtman

I run 40's with 5.38 and it sucks. If I were in the flat lands it would be fine but running up in the mountains it sucks.

AimTime

Alright, I'll do some more research before I go and get bigger tires and my axles.

Trail Jeeps

Fact of the matter is I think you're just asking a lot out of a 3.8. You might just have to live with it. I'd jam some 5.38s in there if you got big axles coming along. Just run it till it dies, it'll be slow. I'm not saying don't get a Rubicrawler I mean that's a fantastic piece of gear, I'm just not sure that it'll get you to where you want to be, but then again, maybe it will?

zstairlessone

I don't know about the automatic, but my 6 speed is only about 2600 at 70 with 4.10 and 34" tires.

You can use the Rubi crawler for steeper hills to get up to speed if needed. That 3.8 will be singing, but that may be what you want/need.

Edit: in hills (not even mountains) mine is a dog like it is.