242 vs 231 comparo

[Creepy]

blew another 231.

so as i'm creeping around the APJ yard, i see a 242 xj. hmm, i liked my AWD 249 is the snow, the 242 has that, plus everything the 231 has. sold.

but is it as strong with all the extra whirly gigs flying around inside of it? the answer is a resounding YES.
In fact, the 242 appears to be quite a bit stonger in a few areas.

The mainshaft thru the case is same diameter as the 231. so equal there. the 242 will fail the same at the tailshaft section like the 231 weak spot.

BUT, the chain gears are wayyy bigger, the chain is 1" wide, (231 is 7/8"), and check out the front output!! it's huge. as big as aftermarket d300/d20 outputs.


1.450" 32spline 242 vs 1.125" 26spline 231 front out put yoke.



242 assembly, 231 shafts. look at the difference in the size of the chain gears, and increased chain engagement. should really help "streched chain popping noise" of the 231.


this is a 231 front output shaft on top of the 242. the rusty brown gear compared to where the chain is on the 242 gear. quite a difference is diameter. It's important to note that strength increases are not linear with increase in diameter. ie: a twice as big diameter will be more than twice as strong.


i'll put up an over-all length comparo this evening, after i get the 231 out. but i've done it b4, they are the same within 1/4"

[itsakeeper]

cooollll!!!

[NW]

Jan, here's the numbers on the torsional loads:

As the diameter of a shaft increases, it's torsional load capacity increases by a cube factor. Double diameter = eight times strength.

The difference in diameter between these 2 outputs yeilds about 2.14 times the torsional load capability.

The difference in chain is crazy! This appears to be a much tougher case.

See how long before it's guts are all over a trail! heh heh

-Neil

-Neil

[2XS]

while all the parts you looked at are much tougher, the down side is the differential that is in there. it is weaker then the 231, and the weak link of the t/c. also about 800$ when you blow it up to replace, unless you can find one used.

[Creepy]

i have a used one. ;D

not sure i agree tho. the mainshaft is the same diameter thru the case as 231. the diff is only in use if you are wheeling in AWD. I wanted that for on-the -road snow driving.

so i figure if you use regular 4x4 wheeling, you should be at the 231 strength, plus the noted bigger stuff. The diff in the case would not be in use during hard wheeling.

that's my understanding of how the 242 works.

[justajeep]

Your understanding would be correct Jan. When in AWD, the sliding collar just engages the diff, and when all the way in, it engages the sprocket, just like a 231.

[MFR]

Jan, wasn't there a difference in the input shaft diameter and spline count? I think the 242 was actually smaller, but the 231 piece fit right in. Making for an even stronger 242.

I was waiting for Neil to drop by with his math skillz

[Creepy]

that was the front input GEAR.

went from 21 spline to 23 spline to match my aw4. so, yes, now a stronger input as well. all the jeep stuff over 95 uses 23 spline tho, so i didn't mention it.

[Sandboxcowboy]

I drug my donor XJ home last weekend, i think ive got a 242 in that. If so, it'll be goin into my YJ!
Ill just have to get a new SYE kit for it.
Justin

[Creepy]

Justin, the tailcone on 242 is same as 231. so you can reuse that part. if the mainshafts are the same ,
you can swap the sye stuff to the 242.

i have 231 shaft out, and a spare 242 case i can dis-assemble to check. next week tho, daddy drinks!!!

[justajeep]

I pulled apart the 21 spline 242 I picked up for the Eagle today. Unfortunately, the chain sag follows the curve of the case!

Want to part with the chain in that spare 242 you have Jan?

[Creepy]

i kinda need it for a spare as i'm now running a 242 in the Grand. sorry.

i try to keep one spare of all my running gear around at all times. I'm sure you understand.

edit: oh yeah, the reason i have the case anyway, is i swapped it out for a guy last year cause it was "popping", his terms for the noise. so the chain is prob bad anyway.

[justajeep]

I didn't think you'd want to part with a good chain, but it never hurts to ask!

[littlemulticoloredwagoneer]

I have one alan... drop me note and lets talk