Can a stock 231 t-case survive behind a 4:1 Klune V with stock AW4/4.0L in a XJ?

Brett pm'd me a few times and told me that it wouldn't and I really appreciate his input, who can comment on this who has run a klune v in front of a stock 231 t-case. I mean stock internally, no heavy duty chain, etc, SYE is o.k. I can get a Klune V for a very good price and I was wondering who has run the Klune V in front of a 231 t-case and if it is surviving. With the torque of the 4.0L and the 4:1 gearing, this would be the equivalent to a 900 ft/lbs producing motor on the 231 (225 ft/lbs * 4). What do U guys think? I have a 35 spline alloy shafted 9" and alloy shafts in my hp44 so I'm not to worried about them. I plan on just idling over obstacles now that I could have 16 gears with the aw4 auto in my XJ/231/klune v, so I doubt I will get 900 ft/lbs out of the motor because this is only achieve at over 3000 rpm or something like that. Also people with manual trannys in your XJs and the stock 231 please comment. I'm just asking if the stock 231 will survive a klune in front of it. Please advise.

thanks,

Troy

YES! Through all my extensive research, searching the internet, and JU! You'll be just fine, enjoy your new toy. Keep us posted.

However I do not have any actual experience, since I do not have a Klune. I would be more worried about the 231 holding up to the those 37's.

I've already told Troy all my reasons, but I'll express them here for public scrutiny:

Reliability - Troy keeps saying a main goal of his current build is reliability on 37s. As far as I know he doesn't have a tow rig. He wants to be able to drive from Sacramento to JV, run hard trails, and drive back. Quadrupling the torque entering a relatively stock np231 will greatly hurt reliability.

Cost - He is getting a great deal on the Klune, but he could simply sell it at a profit and hook up a wheeler who actually needs it, someone with a manual tranny.

Necessity - He doesn't need it. Low diff gears (5.38/5.43) with an auto tranny is all one needs when on 35s or 37s. If you gear too low you can not stop the vehicle without putting it in nuetral, this will hurt performance. If he still needs more gearing (unlikely) he could get a 4:1 and still break even or profit off the Klune sale, and be far more reliable.

Brett just let him do it. BTW, how many have a Klune here on anyway. If he breaks it, he can just get a D300 or something.

Thanks U guys. Brett I really appreciate your time and comments, U know your stuff. U the man.

I won't go into specifics here, but lets look at this from another point of view - that the Klune produces 4 times the torque into the 231. Compare it to:

4 times the horsepower - would you expect the 231 to hold up to 720 HP? Don't know of anyone who would, but that is four times the input....

4 times the resistance - that would stress the 231 from the other way. Would anyone expect to use the 231 on a 14,000# rig - sure don't see the 231 in big trucks, there may be a reason.....

Now, if you wanted to run a gear box AFTER the 231, that is another story - the 231 will only see the torque that it sees now (unless you change motor or tranny). Anyone ever tried doubling up on 231's? Doubt that even 2.72 times the torque would allow the second 231 to survive.
Don't forget torque multiplies each time you reduce speed i.e. 225# at motor, torque converter(2x225=450), low gear (450x3=1350), transfer case (1350x2.72=3672), axle (3672x4.56=16,744) ***numbers off the top of my head to illustrate***
HTH

(Not quite sure if those torque comparisons are realistic..... )

I'm assuming you have a 23 splint input shaft(?)

How long before you can upgrade the inners on the 231? That's the key here. I would upgrade the case at the same time you add the Klune, otherwise you'll have to pull it all apart again. Buy the Klune, be patient, get the 231 HD pieces, then in time put it all together-correctly. And expect to sculpt away like Michelangelo on your floor/tranny hump. If you want to clock your t-case a bit, you'll have to get even more creative. Most likely will have to cut the section above the t-case and slid it back 7 inches or so, then put a panel over the hole.

You'll also have drive shafts to deal with. Plus lengten your shift linkage. And you'll possibly have to lengthen your speedo cable, but thats easy, you can purchase an extension cable and they're inexpensive.

You'd be better off with a 2.7:1 Klune and a 4:1 t-case, though.

XJZ said:

(Not quite sure if those torque comparisons are realistic..... )

I'm assuming you have a 23 splint input shaft(?)

How long before you can upgrade the inners on the 231? That's the key here. I would upgrade the case at the same time you add the Klune, otherwise you'll have to pull it all apart again. Buy the Klune, be patient, get the 231 HD pieces, then in time put it all together-correctly. And expect to sculpt away like Michelangelo on your floor/tranny hump. If you want to clock your t-case a bit, you'll have to get even more creative. Most likely will have to cut the section above the t-case and slid it back 7 inches or so, then put a panel over the hole.

You'll also have drive shafts to deal with. Plus lengten your shift linkage. And you'll possibly have to lengthen your speedo cable, but thats easy, you can purchase an extension cable and they're inexpensive.

You'd be better off with a 2.7:1 Klune and a 4:1 t-case, though.

Click to expand...

Time to place a call to Rawbrown...



Why not buy the Klune, sell it, and maybe do a 4:1 t-case (like the Rubicon) or gear set for the 231 (you might want to ask about the reliability of these also). Too many gear options can be a real hinderance sometimes. Get some seat time, then you'll know if you need to do anything else or not.

I'm just asking if the stock 231 will survive a klune in front of it.

Click to expand...

I seem to remember someone with that combo in their sig. I cant remember who it was, but you should ask them how it is holding up.

wait a minute....

Capt. Nemo said:

Get some seat time

Click to expand...

ding ding ding! we have a winner.

NCSUcherokee said:

I seem to remember someone with that combo in their sig. I cant remember who it was, but you should ask them how it is holding up.

wait a minute....

Click to expand...

hahaha.... nice :laugh3:

Capt. Nemo said:

Time to place a call to Rawbrown...



Why not buy the Klune, sell it, and maybe do a 4:1 t-case (like the Rubicon) or gear set for the 231 (you might want to ask about the reliability of these also). Too many gear options can be a real hinderance sometimes. Get some seat time, then you'll know if you need to do anything else or not.

Click to expand...

That's exactly what I was thinking. Buy the Klune, sell it for a profit, and get the Rock Trac Rubi t-case. For the price I would pay for a Tera 4:1 for the 231, I could get the Rubi t-case for and have a much beefier t-case to work with. Stronger plantary gears, stonger/wider chain, etc etc. That's the route I think I'll go with. I see the points U guys are making, I thought the same thing, but why make the klune campatible with the 231 if the 231 will not hold up to it???

Big Red said:

but why make the klune campatible with the 231 if the 231 will not hold up to it???

Click to expand...

because of people like you :wave: