Chasing 231J leaks
- Thread starter macleanflood
- Start date
Ok...been a long couple of days.
Pulled the skid, drained the case and tried a different skinnier o-ring. Fail. Still leaking. Tried the plan B transfer case plug w/original o-ring. Fail. Doped up the plug with RTV and didn't let it cure enough...also fail.
Pulled apart the plan B case. Looks to be a 92/93 casing. Front snout is completely different but the bolt holes line up with my parts.
Pulled my transfer case. Pulled it apart. Absolutely zero signs of a case crack inside. Worst thing I saw was my oil pump inlet screen clogged up with the plastic chunks of a failed speedo gear swap.
Completely at a loss here. No smoking gun.
Here's the plan. Going to put everything back together with Right Stuff. And hope after 16 attempts to get this to stop leaking it just does.
-Mac
Pulled the skid, drained the case and tried a different skinnier o-ring. Fail. Still leaking. Tried the plan B transfer case plug w/original o-ring. Fail. Doped up the plug with RTV and didn't let it cure enough...also fail.
Pulled apart the plan B case. Looks to be a 92/93 casing. Front snout is completely different but the bolt holes line up with my parts.
Pulled my transfer case. Pulled it apart. Absolutely zero signs of a case crack inside. Worst thing I saw was my oil pump inlet screen clogged up with the plastic chunks of a failed speedo gear swap.
Completely at a loss here. No smoking gun.
Here's the plan. Going to put everything back together with Right Stuff. And hope after 16 attempts to get this to stop leaking it just does.
-Mac
My gut feeling is that damn shift detent plug.
I feel comfortable saying it's not a cracked case.
I think if I used right stuff instead of blue RTV on my previous attempt it might have worked.
But I've thought I've found the problem at least a dozen times.
Got the case glued back together and back in the Jeep. Going to wait until tomorrow to fill it.
I leave Thursday morning for a six hour drive north and a weekend of wheeling. As long as I didn't make it worse I'll be fine even if I'm taping pig mats to the skid and carrying a gallon of ATF.
-Mac
Just glad you're going to be able to make the trip!
Mac is a serious Energizer Bunny... He runs circles around guys half his age. And I don't even try to keep up... I'm OLD & Fat.
Man, I’ve been right there with a stupid TCase leak going out my mind. Shift detente was one offender. Another was the front seal. Somewhere I’ve got the part # for that o-ring if you need it. I’ll go look.
Mac, my last time was the 4wd selector o-ring. Take a look at this post, see if this could be your culprit, and the next post has the o-Ring part # if needed.
https://wranglertjforum.com/threads/05-flame-red-tj-build.3998/post-1504039
https://wranglertjforum.com/threads/05-flame-red-tj-build.3998/post-1504039
I've replaced the the selector o-ring and the bushing. It was leaking from there. I believe I used that very post.
It's now primarily leaking from the detent spring holder...and I've tried two o-rings and blue RTV that sat for 20 minutes and didn't work...no surprise.
Case got split last night and glued together with Right Stuff. So did the detent screw...plan B screw with OEM o-ring. I'm 99 percent postive I don't have a cracked case.
My big question to everyone is what the hell caused this? Coming back from Moab...about 3/4 of the way back it pretty much started puking transmission fluid out of the front seal, the shift detent, the shift selector and possibly between the case halves.
Case was split three, four years ago for slip yoke eliminator and glued together with grey high torque.
Only suspicious thing inside was the oil pump pickup screen was choked with chunks of plastic speedo gear (long story...figured out you have to clock the gear the hard way.)
Vent is functioning.
Now I was getting front driveshaft vibrations. My alignment went to hell...all my Savvy control arms rolled everywhere because I didn't tighten the nuts hard enough.
So my best two theories are oil over pressurization from a clogged pickup filter...which makes zero sense...and two...just shaking the crap out the t-case because the axles were almost and inch out of square each. Which probably caused the rear driver shock to blow.
And I still don't know if I've fixed it yet.
I'd order an Atlas or a Colossus but I'd be tempted to do front digs...that would kill my Dana 30. That and I don't have $4k to drop on a box. Or $10k on the axles to support it.
Trying to get this to stop leaking so I can redo my alignment which I honestly think caused the issue...even though all the bearings, chain, case everything looks perfect.
-Mac
I guess it could have shaken and the case half seal just gave up. I know the Right Stuff was all I could get to seal my case halves. The others IDK. I just sold a complete 231J about a month ago. I also have tons of 231 parts including a front half. Let me know if you want something since I’ll see you R-F this week.
I used Permatex ultra black gasket maker on mine and that stuff is good. So good I have a hell of a time getting the tail housing off!
Another theory (wild guess):
Maybe the front yoke nut loosened. That would let lube seep past the splines and the rubber "gear" seal, and spray everywhere from the center of the yoke. That could soak the front seal, the shift detent, the shift selector and the case halves. It would also cause the front driveshaft to vibrate.
I just had a similar hunt for a sneaky leak on mine, and it was the rear yoke nut. Still snug but not at proper torque, just loose enough to break the seal around the splines.
Maybe the front yoke nut loosened. That would let lube seep past the splines and the rubber "gear" seal, and spray everywhere from the center of the yoke. That could soak the front seal, the shift detent, the shift selector and the case halves. It would also cause the front driveshaft to vibrate.
I just had a similar hunt for a sneaky leak on mine, and it was the rear yoke nut. Still snug but not at proper torque, just loose enough to break the seal around the splines.
Mac, I am praying your piston holds together for you on your trip and you make it back safely.
Think it's that bad?
Maybe I need to borescope the engine.
It's pretty much sounded like that from day 1...but then again slow boiling a frog.
-Mac
Does a 4.0 really need all 6? lol
I don't think a boroscope will really reveal much. I think it's a catch 22 on how long the pistons stay together. Some of these engines seem to be going 10s of thousands of miles with cracks. Then others break the skirts and can destroy the cylinder.
It is the skirt so a scope won't show you much.
Sounds pretty bad if the camera was picking it up that clearly from underneath.
Go for it and deal with it when you get back.
Well, then tell me what pistons, rings and crank and rod bearings should I be shopping for?
I know DeXJs sells used piston sets. I have a press...so that's not an issue.
Behind door two is a 160k mile used 4.0 and 32rh with factory cruise control sitting in my yard. I am half tempted to yank the harness, HVAC box, controls, steering wheel and complete engine and PCM.
But it's a complete unknown. I think before I exercise door two two...
Option C - stroker kit...
-Mac
I know DeXJs sells used piston sets. I have a press...so that's not an issue.
Behind door two is a 160k mile used 4.0 and 32rh with factory cruise control sitting in my yard. I am half tempted to yank the harness, HVAC box, controls, steering wheel and complete engine and PCM.
But it's a complete unknown. I think before I exercise door two two...
Option C - stroker kit...
-Mac
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