Center Difflock slipping

[tweeek]

This is on a 93 non VC x case.

If I am stationary and activate my cliff lock switch, the cliff light comes on solid and ABS deactivates.

Today, once I start driving, the center diff light would start flashing and I can hear/feel the cdiff disengaging. If I continue to drive it will lock in/slip out continuously. It is somewhat intermittent, yesterday I used it in the snow and it was rock solid, today, with many attempts, it was nearly useless, and I have experienced the same symptoms in the past.

I have read many threads of cliff not engaging period, or no lights but nothing for slipping out. Trying to figure out whether I start looking electrical or mechanical.

 

[Malleus]

Sounds mechanical to me, but don't take my word for it. Check the FSM Drivetrain, Transfer, "Motor Shift Control System" section for your truck. The control relay should be behind the driver's kick panel. These are from the '94 manual, but I think yours is the same (w/o the ABS, of course):

If the relay checks out, the problem is either the motor actuator, or the internal shift lever mechanism.

HTH

 

[tweeek]

I can hear the motor actuator running and actively locking and unlocking, when standing still hence the light engaging solid. So I know the motor is getting voltage. I'll run through the electric side of things anyway. The problem for me will be that it is 100% functional when in my driveway.

FYI the reason I have ABS and a 93 non VC tcase is a drivetrain swap from an HDJ81 into my 97 LX. All the electrics on the tcase are the same tho. HF2A.

 

[Malleus]

Yeah, I have those driveway perfect operations myself. I've never had a car strand me at home.

Keep us posted on your situation.

 

[tweeek]

Well I believe I have ruled out and electrical issue. I locked the center diff while in the driveway, cdiff light came on solid, then pulled the 30amp Diff fuse. The cdiff is still slipping in and out of locked condition while driving, sometimes with a clunk. This at least tells me there is not an electrical condition "telling" the motor to deactivate.

Is it possible that the motor is not pushing the actuator rod in far enough to fully engage the lock? I have had the actuator off before when installing 3.11 gears in the Tcase. I wonder if the actuator rod wasnt quite in all the way when I reinstalled the actuator? Just thinking out loud, does this make sense?

 

[shocktower]

Well I believe I have ruled out and electrical issue. I locked the center diff while in the driveway, cdiff light came on solid, then pulled the 30amp Diff fuse. The cdiff is still slipping in and out of locked condition while driving, sometimes with a clunk. This at least tells me there is not an electrical condition "telling" the motor to deactivate.

Is it possible that the motor is not pushing the actuator rod in far enough to fully engage the lock? I have had the actuator off before when installing 3.11 gears in the Tcase. I wonder if the actuator rod wasnt quite in all the way when I reinstalled the actuator? Just thinking out loud, does this make sense?

That maybe your problem, the the pin not, locking in where it needs to be, so I'd go in there and see if it is going far enough, also did you perhaps shim it to far out so it cannot travel far enough, to engage

 

[Funner]

Are you sure it is actually disengaging and not just a case of the dash light being somewhat intermittent?

 

[Tools R Us]

...
Is it possible that the motor is not pushing the actuator rod in far enough to fully engage the lock? I have had the actuator off before when installing 3.11 gears in the Tcase. I wonder if the actuator rod wasnt quite in all the way when I reinstalled the actuator? Just thinking out loud, does this make sense?

When the actuator was installed, was it properly timed, both actuator and transfer gears fully in the locked position?

 

[tweeek]

Are you sure it is actually disengaging and not just a case of the dash light being somewhat intermittent?

Yes, if under load if will sometimes have a noticeable clunk as it comes out. The traction difference is notable when it slips in and out a couple times on a snowy hill by my house as well.

When the actuator was installed, was it properly timed, both actuator and transfer gears fully in the locked position?

I didn't dismantle the actuator. My technique when I installed the 3.11 gears was

lock cdiff
Remove actuator assy
Perform work in tcase
Lock diff manually with screwdriver
Reinstall actuator assy

I thought timing was only necessary if dismantling the assembly?

 

[Tools R Us]

The timing of the actuator to shift shaft in the transfer needs to be correct. If the shift shaft in the transfer isn't fully locked when the actuator is installed, it can't fully shift it to locked.

 

[tweeek]

The timing of the actuator to shift shaft in the transfer needs to be correct. If the shift shaft in the transfer isn't fully locked when the actuator is installed, it can't fully shift it to locked.

Yah I figured this much when I reinstalled the actuator before, but at this point it's my only running theory. It has worked just fine many times

I really don't want to drop the tcase. I'm hoping I can get in there by just dropping the xmember a few inches.

 

[tacoma2002]

Lower the transmission/transfer case crossmember with a jack and support the crossmember on jack stands. It'll drop down a good 3-4".

There is enough room to get to the bolts with a ratchet wrench. You will have to work by feel only...you cant see sh*t up there.

Good luck.