NP231 T-Case Slips Out of 4HI - Gets Stuck in 4LO (AA SYE installed)

[Demonoid369]

Stop putting it in to neutral as you go from 2hi to 4hi, we all have told you you do t need to do that, even the manual says that.
Have you checked your shift fork pads? Might be worn down.
You need to keep it in drive so that it can engage. Only put it in neutral WHEN YOU'RE GOING FROM 4HI TO 4LOW

 

[beasticles]

Stop putting it in to neutral as you go from 2hi to 4hi, we all have told you you do t need to do that, even the manual says that.
Have you checked your shift fork pads? Might be worn down

When in Drive, the shift case lever won't shift "release" up into 4HI like it will when I am in neutral.

 

[beasticles]

BTW I am "this" close to taking it into the local 4WD shop I just figured I would post up here one more time for any more thoughts.

 

[Demonoid369]

When in Drive, the shift case lever won't shift "release" up into 4HI like it will when I am in neutral.

What do you mean by "release up"? You're pulling the shift handle down from 2hi to 4hi while driving. Leave it in drive, let go of the gas pedal, shift into 4hi then tap the gas pedal to make sure it's engaged. Have you done that or just ignored it?

 

[beasticles]

What do you mean by "release up"? You're pulling the shift handle down from 2hi to 4hi while driving. Leave it in drive, let go of the gas pedal, shift into 4hi then tap the gas pedal to make sure it's engaged. Have you done that or just ignored it?

Thanks. With the transmission in Drive, wheels rolling, foot off gas, when I try to pull the shifter up towards me (you say "pulling the shift handle down" - not sure I follow that) from 2HI to 4HI, the shifter will not move upward. There is resistance, and I can tell 4HI is not engaging because the shifter will not move all the way into 4HI position. That said, when in neutral and stopped, it will shift into 4HI but I have to hold it in place.

One more thing I didn't mention was when engaged in 4HI (again, by holding the shifting up into position), I can hear some light clinking noise that comes and goes.

Most likely going to need to tear the np231 down to see what is going on or take it to a shop.

 

[outlander]

Sounds like the detents on the range/mode selector inside the case are messed up or the shift forks are bent or broken....not what you wanna hear but thats my thought

 

[beasticles]

Sounds like the detents on the range/mode selector inside the case are messed up or the shift forks are bent or broken....not what you wanna hear but thats my thought

If that was the case, would my transfer case still be able to operate in 4HI and 4LO? Right now, once I get it into gear, it will operate appropriately, the problem is shifting into gear.

 

[outlander]

In your first post to the thread you said you shifted into 4wd while in drive and it made a grinding noise
did you let off the gas first before you "jammed" it into 4wd?

I suspect not as evident of the pics you posted of your resulting bent linkage.

That makes me believe that the driveline was under torque when you shifted and resulted in bent forks or messed up shift detent and or mode selector.

I also think that your initial shifting problems were due to a out of adjustment shift linkage so now that you have your linkage problem resolved with the boostwerks set up its time to open the case up and look at your internals.

 

[outlander]

One last thought:
is you tranny mount good?

 

[beasticles]

When did your problems begin?
after the sye installation?
Symptoms also mimic linkage that isnt adjusted correctly

They began after SYE installation. It's definitely tied to that. I did have a bent t-case linkage which I thought was the culprit, but turns out it was not the issue. I rarely use 4WD which is why it took so long for me to notice.

 

[beasticles]

In your first post to the thread you said you shifted into 4wd while in drive and it made a grinding noise
did you let off the gas first before you "jammed" it into 4wd?

I suspect not as evident of the pics you posted of your resulting bent linkage.

That makes me believe that the driveline was under torque when you shifted and resulted in bent forks or messed up shift detent and or mode selector.

I also think that your initial shifting problems were due to a out of adjustment shift linkage so now that you have your linkage problem resolved with the boostwerks set up its time to open the case up and look at your internals.

Thanks I plan to take it apart and sort it out. Additionally, the trans mount is less than 3 months old.

I honestly think I let off the gas before forcing it into 4WD but can't remember for sure. What a pain - only myself to blame! :nosmile:

 

[beasticles]

Tore the t-case down tonight. I am almost positive the issue was that I installed the shift sleeve for the fork backwards when I put the case back together after the SYE install. IDIOT! I took lots of pics and will post up photos of what I am talking about tomorrow. As a newb to working on the transfer case I can see how easy it would be to overlook this. Looks like minimal damage to the internals.

Do my symptoms of trouble shifting now sound familiar?

See another post about this as well http://www.naxja.org/forum/archive/index.php/t-86202.html

 

[beasticles]

So here is a quick breakdown of the t-case breakdown. Basically I almost missed the fact that I installed the shift sleeve on the fork backwards after the SYE install but caught it after looking at helpful links from Moses Ludel, 4x4xplor, and others online. Images at the following links show the correct positioning of the shift sleeve:

http://www.4wdmechanix.com/Jeep-XJ-...Rebuild-Part-1,-Disassembly-&-Inspection.html

http://www.jeepforum.com/forum/f12/sye-install-np231-still-695330/

http://www.4x4xplor.com/SYE-CV3.html

Here is a pic of the breakdown:

This picture shows the shift sleeve as I had installed it at the time of SYE installation - Backwards:

I put together this pic really showing the difference between the wrong and right direction for the sleeve:

The result of installing the shift sleeve backwards was a little bit of scoring on the drive sprocket (the lighting makes it look a lot worse than it is - there was no chipping of the teeth):

And some metal shavings on the magnet:

Here it is ready to be buttoned up. This where I stopped for the night. Hope this helps someone else.

I don't plan to replace the drive sprocket unless you guys think I need to. I think it looks fine as is. I carefully inspected all other components and everything looked fine.

 

[beasticles]

This completely resolved the issue.

 

[DeftwillP]

Well....we've all been idiots before at least once.

 

[beasticles]

:banghead: <-- This is how I feel, but I don't care since I fixed the issue for free. I was moments away from taking it to the shop - I stared at the transfer case for a good five minutes before sucking it up and disassembling. I am glad I did.

 

[outlander]

Is your chain stretched?
Looks saggy from here...

 

[beasticles]

Is your chain stretched?
Looks saggy from here...

It looks worse because the front driveshaft gear was not fully pushed back into place. But yeah I thought that too.

 

[Boostwerks.com]

Is your chain stretched?
Looks saggy from here...

FWIW, without the tail housing installed it's impossible to tell. :thumbup: