4.10's would be good, or even 4.56's. Mine has stock gears, and it still does pretty good getting up and over rocks, and still plenty powerful in town.

 

sweet thanks

 

for best crawling, you want a final drive ratio as close to 100:1 as possible.
so go low gears and even a double transfer case set up.

dual t-case is probably cheaper and easier to do than regearing.
if you already have a 231, all you need is a dana 300 and a doubler kit, like the box4rocks kit. you can pretty much do the install in your garage yourself, all except for the welding.

do that and you will crawl anything, especially if you're locked.

 

Right now I have a manual and like it for mud and dding but if I was building a purpose built rock rig I think auto is the way to go. If your worried about the torque converter, there are ways to lock them. I think I saw a thread on it a few weeks ago on here.

 

It is preference and driving style. i have over 50,000 on my centerforce clutch and it feels like the day I got it and I crawl with the thing. if you know how to use a clutch effectively you dont have to worry about it burning up.

some like autos because it is less to think about it and a bit easier

 

1 vote for auto. upgrade the brakes anyway you can, make sure you have a good tranny, and converter, and run it.

 

i have the rubicon xpress 4.5 on 33 w auto...never had any problems crawlin....u will rub a bit in the front when you tire is tucked in from being on a rock....i will take some pics of mine where u might rub and post them in a bit

 

its not letting me post them

 

with trimming in the right places, correct bump-stopping, and the proper offset wheel you should be able to run 33"s on a 4.5 no troubles. I have 32" on 3" with no rub, just cause i haven't got the $ for 33"s yet. Someone in my local club has 35"s on 4.5.

I would (and have) stay as low as possible, get some lockers, and guard up.

 

Xj's aren't good for crawling. If you want to crawl get a buggy or something else. Xj's are mall rated not trail rated.

Just kidding everyone. Believe it or not I was actually told this by some guy who doesn't even own a 4wd vehicle.

This is more of a personal preference. I doubt one or the other is "better". What's good for you is not always good for the next guy. Your driving style and comfort level will dictate which transmission you should use in your rig.

 

what do you mean they seem to slip? if its slipping than it has a transmission problem. a torque converter is going to have some amount of "slip" but once it reaches its stall speed it should deliver power pretty eficiently. The problem with a stick is that you dont have this "slip" meaning it is always transfering 100% power as long as the clutch is out, unless you are intentionally slipping it which typically results in burnt clutches. Not so much "burnt converters" though. There is really nothing inside a converter (at least at that speed) to burn. there is a stator and a turbine etc.
They do however create a lot of heat. so with an auto you definitely want to make sure that you have some sort of aditional cooling, because again, at the low speed there is no air flow to the cooler minus the fan, and there is a lot of load on the converter generating heat.
so for me a good cooled auto is the best. Ill compromise the loss of engine braking for it.

 

they pull up to a rock and its allmost too much torque. the biggest tire is a 33 and running stock 3.55 gearing. im sure if it was regeared or doubled it wouldn't be an issue. but my manual seems alot smoother with the 3.07 than theirs with the 3.55's. just what i think..

 

I've used both an auto and manual for crawling. The auto is easier, stronger and harder to break, but I think the manual is more fun.
The only way an auto transmission would be slipping is if the driver was in high gear or needed to change the ring and pinion gears for a lower crawl ratio. The manual with stock 3.07 gears can drive over a rock or two, but it will be useless trying to do any serious rock crawling. A Cherokee with a AX15, a 231 transfer case, and 3.07 ring and pinion will have a crawl ratio of 31.98 to 1 that just isn't enough.

 

good info here. automatic, low COG, gears, lockers, gears, no manual, gears, and gears. lol Don't forget about good tranny coolers and an electric fan. In fact, wire the electric fan to a toggle switch so u control it when you want.

The XJ has an awesome wheelbase. It works great for everything! You should get good bumpers to improve your approach and departcher angles also.