I'm dreaming of a white YJ Christmas...

[Wrench]

So, I picked up my YJ today, purchased wrecked at auction.



What it has:
-SOA lift, with an extra leaf on each pack and offset (stretched) spring perches, heavy duty shackles, and what looks like a bolt-on hi-steer bracket
-extended stainless brake lines
-Dana 30hp with lunchbox locker
-disk brake 8.8 rear, open
-4.10's
-the tub has been sprayed on the inside with what looks like Line-X, very professional looking
-the front shock towers appear to have been extended
-it has a SYE with double-cardan rear driveshaft
-Smitty Built soft-top
-small offroad bumpers, rear has integrated heavy duty tire carrier
-2.5l multi-port, AX5, 231J
-33" KM2's, probably about 80% tread
-heavy duty center console/lock box
-front CAD blanked off, not sure how to ID whether the shafts have been swapped with larger u-joint shafts

The bad:
-drivers front spring broken
-front driveshaft bent, took out the transfer case
-front axle pumpkin blew a hole in the oil pan
-passenger front engine mount broken
-rear bumper tire carrier shaft broken off, can be welded back on

Pics:



















Repair process:
-I already have a complete 2.5 engine for parts. Hope to have the oil pan replaced and engine running very soon.
-currently searching for a stock front spring or springs to put the front end back together.

[klinger]

Congratulations. I just picked up my first yj back in September. Mine has Scout dana 44's a soa lift and a amc 360. I was able to take it out for 3 ball but work has kept me too busy for anything else.

[bobracing]

I have (think) the 23 spline input shaft for a 231, short one, if you need it.

[Wrench]

I'm gonna rob the input out of the broken 231, but thanks for the offer. I think the AX-5 is 21 spline anyway.

[Wrench]

-Springs are acquired
-oil pan is replaced

[scumby]

Front axle straight from the accident?

[Wrench]

It appears straight. The u-bolts may not have been as tight as they should have, allowing lateral movement on the spring when it hit. The centering pins/bolts in the springs were also stainless, which are very weak, and were sheared clean off. Most pins I have seen were at least a grade 8, and I believe stainless is grade 3 or 5. Those are not factory, and appear to have been installed by whoever did the lift. The front drivers spring mount rear tabs were bent on the frame, but I used a port-a-power to move them back into place.

The impact dented the front rim a tad and shoved the axle back, breaking the 'case and shoving the pumpkin yoke into the oil pan. The yoke was still turning when it hit the oil pan, and basically drilled a huge hole in the oil pan.

I picked up a set of springs the other day; a worn set of Rough Country 4" springs. I used the top leaves of the RC springs and the bottom 3 stock springs to make my own packs. The RC top spring was just a tad thicker than the stock top spring, but the previous stock packs had an extra/thick leaf in them, which I removed. I effectively lowered the current spring rate and the front sits a tad lower now, but I now have a stronger primary spring.

[Wrench]

Made some more progress.

The front suspension is all lined out. Bump stops and travel measurements/clearances look good. The rear is a different story; the shocks are much too long for the brackets installed and will bottom long before the bump stops contact. Shelve that correction for another day, but I threw a set of shorter shocks on for the time being.

The 241 transfer case will not work with my transmission without extensive work. The inputs were interchangeable, but the clocking of the mount bolts is too far off to be functional. The 231 SYE will also not work with the 241, as the mounts for the tail cone are completely different. On a side note, I found dramatic similarities between the two cases. The entire input, gear reduction, and main shafts are nearly identical and interchangeable. The 241 has a dramatically larger chain, sprocket size, and output shaft size, though. Also, the gear reduction of the 241 has 6 planetaries instead of the 3 that the 231 has.

241 input shaft and planetaries vs 241:


241 main shaft with chain sprocket vs 231 SYE shaft:


231 case half vs 241 case half, notice 241 is much bigger:


BTW, I spent $60 for a set of real nice Proto snap ring pliers for this job. WORTH. EVERY. PENNY!

I also ran into difficulty using the Chevy speed toner ring/sensor on the 241 case for the Jeep, so the 241 case install will be shelved until I get all the parts lined up for the chevy v8 swap.

For now, I'll be putting the 231 from the Cherokee in the Wrangler.

[Wrench]

Got the transfer case installed yesterday.

So here is a little tidbit of info: it appears that some NP231's have the holes drilled in the planetary cage for all 6 gears!

I pulled the transfer case from my Cherokee, which may or may not be a 1986 vintage 231 case. It came from an '86 Cherokee, but appears to have paint markings on it that may be junkyard marks, so I really have not idea what year it is. The 231 tag has it marked "NP231 AMC". While installing the SYE kit, I noticed the planetary cage has all 6 holes drilled, so I told myself, "Self, why dont we steal the extra planetary gears from the broken case and make another 6-planetary set?"

It was actually not too difficult. I used my shop press to press the pins out, but there was not much pressure needed to overcome the peens on the one side. The pins can be pressed out either way, the peens are identical on either side. Once removed, the greatest difficulty was re-installing the pin through all the shims and needle bearings. I used some real thick grease to pre-install it all in the gear and hold it in place while I slipped the pin back through. The pin required some very slight careful grinding to removed the peen expansion, and the surface was re-finished with emery cloth until is slipped freely through the cage holes.

Junk case planetary on left, Cherokee 231 planetary on right:



Needle bearings, total PIA:



Once the pins were all re-installed, I used a punch and hammer to peen the ends again:



Now, all 6 planetaries installed:



This is probably overkill for strength, but it cant hurt. The 231 is now stronger to the rear drive shaft with the added planetaries, and with the extra beef of the SYE. The SYE output is 32 spline, while the old standard slip yoke was somewhere around 23. I hear you can also use a 231HD sprockets and chain from a Dodge to beef up the output to the front, also. The standard 231 chain is 1", while the 231HD chain is 1.25" wide, and the HD has a larger spline output on the front.

[SPR]

Cool stuff. Do you think the additional friction the extra planetary gears would have a measurable effect on heat buildup in the transfer case? Do they only come into play while in 4-low?

[Wrench]

The 6 gear planetaries are factory / standard in the 241's, so there should be no issues at all.

They are only under load when in low range. In hi range, they just rotate with the cage at 0.367 the speed of the drive shaft, and are not under load. I suspect this is why so many have had issues with the Terra Low 4:1 kits; the torque transmitted through those small gears is too much for them. By looking at the outside case of the NP241OR (Rubicon case), you can see that the housing around the planetary assembly is much larger.

[79chevy39.5's]

There are 2 gear pitches for the 231/241s depending on year but you could have just dropped the 241 planets into the 231 if they matched

[Wrench]

I could have, but then my 241 would not be serviceable.

Made more progress today:
-broken engine mount replaced
-exhaust repaired
-new engine oil/filter
-ugly stereo wiring partially removed
-new ignition lock installed (mail was delivered today )
-she runs!!

All engine indications look good, and even the battery seems to be OK.

[scumby]

test run! you've got until new years day.

[Wrench]

I'll have to trailer it. I made an appointment with the State Patrol the day I brought her home, and the nearest appointment they had was Feb 13th.

I need a front drive shaft and front shock first anyway. The shock is on the way, but I still need to source a drive shaft. New Years deadline will be putting the squeeze on things, but is possible.

[79chevy39.5's]

Yakima is usually more available

[Lurch]

Yakima is usually more available

I've heard the same thing

[White trash]

There is a version of the 231 in s10's with 6 planetaries, that is what is in bobracing's crawl box.


The best bang for the buck in those t cases is a 231hd out of a half ton pickup. Swap the input if needed and drop it in with it's 6 gear unit and wider chain. A whole lot cheaper than buying an aftermarket wide chain kit and sourcing the other planetary.

[OldGreen]

Trashy . . . Years and applications on those? Is the case bolt pattern the same?

[White trash]

Off the top of my head the base model (easiest to use since it has a shifter not a electronic solenoid) '94-'02 half ton truck should have the 231HD. Other than the standard input swap it should be a bolt in. The clocking may be different but a standard thin clocking ring fixes that.

[Wrench]

Just FYI, a clocking ring would have allowed my 241 to bolt right up, but the shift linkage would have still been off and needed some form of correction. If the SYE would have fit, this is the direction I would have taken.

The 231HD will never match the beef of the 241. The output shaft and sprockets on the 241 are dramatically larger. If you are going heavy duty, it would be easier to stick with a 241. They are plentiful in the driver-drop variety, out of full-size Chevy's from 1988-late 90's.

[Wrench]

Drove it for the first time Friday! (forgot to post, been out of town all weekend)

Things completed:
-re-worked rear spring packs to make them a more progressive but softer spring rate. It now has more extension and sits lower at ride height.
-got the tunnel sheet metal straightened out and the shift boot reinstalled.
-bled the brakes
-reworked the funky e-brake cable setup. It was binding at full extension.

[scumby]

So it's ready to wheel?

[Wrench]

No.

I have the ends for the front drive line, but need to get some tube and weld it together. I also need to install the new front shock when it arrives. Also, I would have to trailer it (no plates) and dont have the rear bump stops set correct (shocks bottom before bump stops hit).

I test drove it up to highway speeds, and it seems to run pretty good. Sure doesnt have the steam that my Cherokee 2.5 does. I am surprised the front wheel doesnt seem to be bent, she runs pretty smooth at speed.

[Wrench]

Cut the Craigslist drive line apart, measured the tube, and went to Twin City Metals for supplies. Welded it all together today and threw some paint on it to look new.

I used my handy-dandy motorcycle wheel balancer stand to true the ends on the tube. It worked pretty well!







The shock came in yesterday, so I got that thrown on today also:



Just thought I would throw this out there also: y'know those key-locking gas caps? They are pretty worthless. The YJ had one on it, but no key. One tight squeeze with a pair of channel-locks on the ridge running across the top of the cap and the cap twisted right off. That method is even faster than using a key.