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T-Case woes

SwissArmyJeep

NAXJA Forum User
Ok, I finally got the Wife her own XJ, (2.5l, AX5, NP231, 8.25.) Low Miles, Nice body, well taken care of (Yes I'm talking about the Jeep).
The 4wd has a couple of quirks that I must adress before winter.
  • Transfer case lever shifts fine from 2H to 4H, but doesn't move to the right to access N & 4L. Probably a linkage issue that I will look into this weekend.
  • When shifting into 4H it acts like the front brakes got applied. Not to the point of stopping the Jeep, just seriously dragging.
The last one is the one that concerns me! I'm going to start by refilling the t-case with synthetic oil, and then try to drive it in 4H down a dirt road for a strech to see if it "loosens up". The vehicle was towed behind a RV. Owned by an older lady that probably never used 4wd. My concern would be if she towed the XJ out of gear, but did not put the t-case in N. would that have caused damage over time? Aside from tearing it apart, what else should I look for before trying to Loosen it up? Any help would be greatly apreciated.
 
Thanks! Been praying alot since then.:banghead:
I've been thinking about this not neutraling the t-case thing. Just how would that be any different than normal driving? I'm guessing that the transfer case has just not been used in almost a decade, and needs some love.
 
Remember the tcase does not use gear oil. It uses ATF.
 
They do make synthetic ATF, so if you want to use synthetic, just use Synthetic ATF. ATF+4, available over the counter at auto stores and even Walmart is Synthetic. But since everyone recommends Dexron/Mercon, I'd use just use a synthetic version of those.

Towing any vehicle with an automatic transmission, where the wheels will back-drive the automatic trans, is really really bad for the automatic transmission. An automatic transmission has a pump in it to pump the trans fluid thru the trans as it works, the pump runs off the input from the engine. If you back drive the trans from the wheels, that pump does NOT run and pump the oil, but the rest of the auto-trans continues to spin from the wheels. Thats why your supposed to tow the vehicle on the none drive wheels. If you do tow with the drive wheels spinning your supposed to disconnect the drive shaft to the trans. Short distances of towing at low speeds, less than 20 miles should NOT do harm to an auto-trans if do back drive the trans.

BUT, 4WD, putting the transfer case into neutral would be the same removing the drive shaft, because it would prevent the spinning wheels from back-driving the trans.

Could back driving the XFER case, with the spinning wheels from towing, do the same thing as back driving an auto-trans? Its so much simpler than an auto-trans I wouldn't think so, but I don't really know, the XFER case does have a pump that is just like the pump in an auto-trans (propably why your supposed to use ATF for fluid).

Any used vehicle with more than 100k miles, I changed all the fluids, all of them, you just don't know. Hopeully your problem is bad fluids in the XFER case or front axle and it will free up with some good fluid and some use. You may have some bad U-Joints that are binding causing your drag when in 4H.

Finally, do you NOT need to be in Neutral on the auto-trans to shift into N or 4L on the XFER case? Are you putting the manual trans into neutral (shift lever out of any gear in the center of the shift pattern) when trying to shift into 4L or N? The reason I say that, I "Think" shifting the XFER case into N or 4L back drives the trans output shaft a tiny bit, thus if the trans is NOT in neutral, the output shaft of the trans won't turn backwards the tiny bit it needs to, that will let the XFER case shift into N or 4L. So pushing in the clutch pedal may NOT be the same thing as putting the shifter in the neutral position when it comes to shifting into N or 4L for the XFER case.
 
Thanks for the replys!:yelclap:
Her Xj only has 82K on the clock , but I'm changing all fluids anyhow (just got to be sure). Dex II in the t-case, Redline MT-90 in the 5 speed, Valvoline blend in both diffs.
Would towing with in 2H back drive the transfer case? Doesn't 2H diconnect the front drive from the transfer case (as in normal 2wd driving)?
As for shifting the 231, I was at a stop, had the clutch depressed, & trans out of gear. I assume I have some linkage issue here.
My main concern is that the T-case lossens up with use, and doesn't go BOOM.
 
I think, in N the XFER case disconnected everything from the input shaft of the XFER case, some of the planetary gears may continue to spin from the rear output to the drive shaft but they are just idling with no load.

In 2H, a clutch to the front driveshaft is just disengaged, the chain and pump continue to spin with the output shaft to the rear drive shaft. BUT, although towing in 2H would back drive that chain and pump, the pump should still continue to pump oil and be no different than normal driving in 2H.

My guess is, the advice to shift the XFER case into "N" when towing is from the towing the drive-wheels with an Automatic Trans deal. Putting the XFER case in "N" when towing is like disconnecting the driveshaft (as far as the automatic trans is concerned), which is what is recommended when towing on the drive wheels for an automatic trans. Which back driving an Automatic Trans is very different than all the other parts in the drivetrain.

There are a lot of guys on this board that are 100 times more experienced than I with XFER cases, so hopefully they will correct me or point out what I'm missing. But its my guess, that towing in 2H wouldn't do much harm to your XFER case, just your automatic trans, and since you have a Manual Trans, it probably did nothing to your manual trans.
 
OK here is an update.
I put the XJ up on stands to change out the fluids. While it was in the air I tried the 4WD system again. Started the engine, put it in 1st, let out the clutch. Worked good. Pushed in the clutch pulled t-case lever to 4H, let out the clutch, and all four tires spin. No noise, no griding no binding. I push in the clutch, pull the t-case lever to 4L, let out the clutch. All four wheels spin. I got out and stopped one tire per axle to prove to the wife that she has open diffs and what that means.
The next weekend I take it to a dirt road. Push in the clutch, pull lever to 4H, but it wont go into 4L. Try driving down the dirt road, front wheels are dragging somewhat while the back wants to squirrel around. I'm guessing mismatched axle gearing. BUT, why would that keep me from pulling the t-case into 4L?
What am I missing??? Can anyone offer some insight or suggestions?
 
Just a dumb question...have you check to make sure that all 4 tires are the same size and up to pressure? Maybe that's causing the 'dragging' in 4Hi.

When attempting to put it in 4Lo...are you at a dead stop or still moving? For my XJ, I have to be at a dead stop, auto tranny in N before I can shift into 4Lo. It won't shift into 4Lo even moving just a little.

Otherwise, I'd say it is a linkage issue or something inside the t-case.
 
thebrick said:
Just a dumb question...have you check to make sure that all 4 tires are the same size and up to pressure? Maybe that's causing the 'dragging' in 4Hi.

When attempting to put it in 4Lo...are you at a dead stop or still moving? For my XJ, I have to be at a dead stop, auto tranny in N before I can shift into 4Lo. It won't shift into 4Lo even moving just a little.

Otherwise, I'd say it is a linkage issue or something inside the t-case.

Yep, 4 tires match (Brand new). Dead stopped while shifting, Manual Transmission with clutch pressed to the floor. :dunno:
 
What are the odds that it won't let you shift into 4lo with the clutch in?
Just curious.
 
Are you putting the transmission in neutral before trying 4 low? Not just pushing in the clutch, but putting the tranny in neutral has always worked for me.
'96, AX-15, NP-231
 
SteveT said:
Are you putting the transmission in neutral before trying 4 low? Not just pushing in the clutch, but putting the tranny in neutral has always worked for me.
'96, AX-15, NP-231

Wow, It doesn't make a difference on my '93, so I'm not sure I tried that.
I'll check that tonight. Won't explain the front dragging, but it may take the transfercase out of the picture (I HOPE!!).
 
First, Thanks to all who offered some help on this subject! :thumbup::thumbup:
This weekend I finally got around to opening the axles on the wife's XJ.
I'm pretty sure the problem is now diagnosed, and soon to be fixed.
This is what I found in the rear axle.
3.jpg


Funny the front axle matches the build sheet (4.10). So all this put the t-case in a bind. Boy do I wish I could get my hands on the Asshat that thought that was a good fix.
Beware of the non-labeled axle!
:skull1:
 
Rick Anderson said:
I think, in N the XFER case disconnected everything from the input shaft of the XFER case, some of the planetary gears may continue to spin from the rear output to the drive shaft but they are just idling with no load.

In 2H, a clutch to the front driveshaft is just disengaged, the chain and pump continue to spin with the output shaft to the rear drive shaft. BUT, although towing in 2H would back drive that chain and pump, the pump should still continue to pump oil and be no different than normal driving in 2H.

My guess is, the advice to shift the XFER case into "N" when towing is from the towing the drive-wheels with an Automatic Trans deal. Putting the XFER case in "N" when towing is like disconnecting the driveshaft (as far as the automatic trans is concerned), which is what is recommended when towing on the drive wheels for an automatic trans. Which back driving an Automatic Trans is very different than all the other parts in the drivetrain.

There are a lot of guys on this board that are 100 times more experienced than I with XFER cases, so hopefully they will correct me or point out what I'm missing. But its my guess, that towing in 2H wouldn't do much harm to your XFER case, just your automatic trans, and since you have a Manual Trans, it probably did nothing to your manual trans.

Rick, you got me thinking again about something that's always bothered me about the towing instructions:

It's been my understanding for some time now that the 231 case in my '92 does not have what is referred to as a "true neutral" - rather, the front and rear outputs are locked together like in 4H and 4L, but with the transmission decoupled. As a result, I've often been puzzled by people (and the owner's manual) saying to flat-tow with the tcase in N - in my mind, that's as bad as running in 4H or 4L on pavement.

Now, before you say it - I do recall a discussion around here somewhere on this topic some time ago. IIRC, it indicated that some of the later models of XJ did have 231s that had a "true neutral" (later than mine, anyway), but that the exact cutoff wasn't clear. I also seem to remember that the discussion also touched on the fact that everyone's flat towing instructions were the same.

Admittedly, I don't have any plans to flat-tow my XJ (given my vehicles, it'd be more likely that the XJ would be the tow-er, rather than the tow-ee), but I'd be interested in your thoughts.

Rob
 
After a friend pointed it out, it may not have been clear why the 3.55 gears were a problem. Sorry for the confusion.
It was built with 4.10 gears in the factory. The front is an un-molested D-30 with 4.10 gears. This is what put everything in a bind!
 
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