Topic: beef up 231

[drunkencityworker]

Ok I have a 95yj 4cylauto. I just parted out a 87yj 6cyl auto. I kept the tcase. The plate said 231   AMC. its 23 spline and the input sticks out approx 1.5 inches.   My goal is to rebuild this tcase so when I do my 8.8swap it will be ready to bolt in and limit downtime. I plan on going with the jb super short sye. I have been told I can use parts from  the 241c out of a chevy to make the 231 stronger. the 6planetary gear and the hubs for the wider chain. does anyone have a link for this? has anyone else tried this? I was told it should piece together just order new chain. Any and all advice is welcome . Thanks

[Jeffy]

241 and the 231 don't have much interchangeable.  You'd be better off looking for a 231-D or a 231-HD.  They should have a 6 gear planetary and a 1.25" chain and sprocket unlike the Jeep.  Internally all 231's are interchangeable to some extent.

[drunkencityworker]

is my 4cylauto 21 or 23 spline

[oldjeep]

Your auto is a 23 spline.

Upgrading to the 6 gear planetary is a waste of time, you don't have the power to break it and other things will break long before the planetary explodes.

The wider chain upgrade is about $235 for new parts from either JB or AA - also a waste of time behind a 4 banger if your stock chain is in good shape.
http://advanceadapters.com/product/2461/(P/N-29-2320)-NP231-Heavy-Duty-Chain-&-Sprocket-Kit.html

[Bounty Hunter]

I did all those upgrades last time I had my 231 apart, as well as the 2lo and super short SYE.  Heavier parts don't hurt, one less thing to break.  The wider chain will last longer before stretching.

[oldjeep]

I did all those upgrades last time I had my 231 apart, as well as the 2lo and super short SYE.  Heavier parts don't hurt, one less thing to break.  The wider chain will last longer before stretching.

They won't hurt, but we've got guys with 302's, 4.0L's and 350's who are not breaking 231's.  Only really weak parts are taken care of by the SYE.

[Jeffy]

I think if you're planning on keeping the 231 then it makes good sense to beef it up while you're putting in a SYE.

[Bounty Hunter]

They may not be breaking them, but the more HP you add, coupled with the increased leverage we subject the jeeps to when wheeling with big aggressive tires and lockers, the chains will stretch much sooner than in a stock application.  Mine was apart and I had the parts on hand from a 231c and 233c.

[bvincent]

check out MADXJ site. http://www.madxj.com/

Under the Tech section - Transmission.

He did just what you want to do. 

It never hurts to build it stronger and better

[drunkencityworker]

thanks for the links and info... a bud of mine is putting 5.0 in his yj and wants to beef up 231. I am going to put 8.8 in and sye and if I can get jnk yard parts to work why not