4wd stuck on

[TeaBag]

Have a 91 GW-just finished and engine overhaul and got everything hooked back up.

I was having issues getting the 4wd to turn on-so I replaced all the vac lines in from the engine to the switch.

That fixed the issue and when I flipped the switch the 4wd engaged however, now it will not disengage. I checked vacuum at the actuator in both switch settings and both sides have strong vacuum. I even tried tapping on the actuator to see if it was stuck and it still does not move.

The 4wd worked flawlessly before the engine rebuild. The Tranny was not removed when I pulled the engine.

Any thoughts? Anything I should check?

[tedlovesjeeps71]

Can the Vac lines be backwards??


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[REDONE]

So, what is leading you to believe that your 4wd is still engaged? Are you stuck in low range, or just have signs that the front axle is still live?

[TeaBag]

The light is on on the dash and I can feel it when I drive it.

If the vac lines were backward it would just reverse the switch so in other words, when the switch was set to 2wd the vehicle would be in 4wd and the opposite would happen if the switch was moved to 4wd the vehicle would be in 2wd

[Cheapthrills]

I think it may be some super worn parts in the tcase my 91 had this issue... it was like pulling teeth to get it in and out.... low rang was even worse.... the tcase was dry when I bought the jeep... the tcase was NOT HAPPY.... LOL

I had to drive forward and reverse 14million times to get it to switch

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[Stuka]

Shift the trans into neutral, and shift the t-case into neutral (lever under seat) and see if it will then pop out. Also be sure it has fluid in it, an NP case with no fluid basically becomes impossible to shift out of 4wd.

[fulsizjeep]

Been a while since I used an NP229 but I don't think you can get it into 2WD with the flag shifter in Neutral, only 4Hi. I have a right to be wrong.

I do recall having shifting issues once. I had been in Everglades mud for a day and after power washing underneath, the shifter would get stuck. I think I washed years of Jeep lube off the linkage. Don't be afraid to spray some lube on the linkage joints on the vacuum shifter.

[TeaBag]

Got it. Found one of the metal vacuum lines had a leak in it. Also-the vacuum motor shaft was bent so the piston would not retract. I removed the vacuum motor and was able to straighten the shaft in a vice. Test the motor and it worked perfect. After replacing the leaky metal vacuum line with rubber hose, I reinstalled the motor and all works well.

Stuka- Good call on checking the fluid. I only had about a pint of fluid (holds 6 pints) in mine. So drained and added fresh stuff while I was at it.

[fulsizjeep]

Good News!