New to me 97 FZJ 80 Triple locked - Both Lockers wont disengage?? (1 Viewer)

[Damcowboy]

Hey guys, I am the new owner of a 97, triple locked, FZJ-80. I've done a bit of maintenance on it so far, new rear main seal, new bearings, rings and seals in the rear and new brake pads all the way around. When I bought the FZJ I tested the lockers and 4 wheel drive in a field and everything seemed to work, at least it felt like it and all the dash lights came on as required. I had the vehicle inspected and they determined that everything worked (I don't know what they did to check this). What I didn't do was jack up one wheel in the front and the rear and see if the tires rotated together when locked and separately when not locked.

While doing the work on the rear end I noticed that the tires where rotating together, and the diff should not have been locked. Once I got the rear all back together I drove on a dirt road to see if I could get the lockers to engage and disengage a few times. According to the dash lights everything was good, but when I jacked up one tire in the rear I couldn't rotate it. Correct me if I'm wrong but this means the rear locker is not disengaging correct? The same thing is happening when I jack up one of the front tires. So am I right this means the lockers are not disengaging? It didn't really feel bound up when I drove it a short distance but I am sure it is as the tire I jacked up spun a bit when I lifted it off the ground, indicating it was bound up.

I have found some threads about rebuilding the locker actuator but for now I just want to disengage them. I haven't' found a thread (with pictures) yet that explains how to remove the actuator and/or disengage it. I started to take the rear actuator off, removed the 4 bolts attaching it to the diff but it wouldn't pull off easily (it seemed to be held somehow by a spring?) and I didn't want to force it. I started to remove the round plate on the side facing the front of the vehicle (held on with 3 10mm bolts) but as it started to come off I felt some spring tension so I stopped, I didn't want to release some springs in there with no idea how to put it back together. I then removed the large "piston" with the electrical connection attached to the top of it, immediately on the diff side of the actuator, as well as the plate it is screwed into, that is bolted to the diff housing. Behind that plate I could see the bolt that actuates the locker but couldn't figure out how to disengage it (retract it correct?).

I haven't messed with the front actuator at all yet.

Guys any help? There must be a thread here somewhere that explains how to disengage the actuators?

 

[Damcowboy]

I found a thread started by e9999 in 2004, checking that out now.

BTW I checked the fuses and cleaned the connections on the actuators, no luck.

 

[ppc]

@Damcowboy Your description seems to be normal operation. One wheel in the air with transmission in park is not going to rotate. Put transfer in neutral then it should rotate. Both wheels raised, transfer not in neutral, they should rotate in opposite directions .

 

[Damcowboy]

I had both the P-R-N-D shifter in neutral and the H-N-L shifter in neutral. Neither the front or rear tire that I lifted in that condition would turn. If its not in 4wd shouldn't the individual tires rotate on their own?

 

[ppc]

@Damcowboy With all the mass and friction in the drive line it's not going to spin freely but takes some effort. Try lifting both wheels on the same axle. They should rotate in opposite directions. Do that front and rear. Other than that you may have a failed vicious coupler.

 

[Damcowboy]

When I had both rear tires lifted while doing the other maintenance both tires would rotate together in the same direction. I haven't had both front tires on jacks yet so I don't know what the result of that might be yet.

I have no idea what a vicious coupler is, I'll have to look that one up.

 

[ppc]

If the dash indicator for the rear cycles on and off as expected then your problem most likely is not the locker. Was the handbrake released?

 

[Damcowboy]

If the dash indicator for the rear cycles on and off as expected then your problem most likely is not the locker. Was the handbrake released?

Yes it was

 

[Damcowboy]

Assuming it is the lockers, is there a way to manually move the actuator armature to the unlocked position? If I do that and the tires still don't rotate as expected then at least I know its not the lockers. For now I don't need 4wd, I just need to get it driving again without damaging other driveline parts..

 

[ppc]

I still think it is highly unlikely you have the same problem with both front and rear lockers. I suggest you retest what happens when you lift both wheels on the same axle making sure of your results. If both rear wheels rotate in the same direction then the transfer case is in neutral or transmission not in Park. Something would have to rotate in the reverse direction.

At this point I would not mess with the actuator. You can pull the sensor switch and observe the position of the locking collar when the locker is turned on and off. Stick you finger in the opening and see if you can move the collar further in the unlocked position. I've never removed the actuator myself and would have to defer to someone else for any advice. There are several threads to search on installing and clocking the actuator.

 

[Damcowboy]

Ok, I copied this picture from a thread from Clownmidget. I have removed the plate that covers the bolt shown in the arrow facing down. I think that's the plate you are referring to when you say the the sensor switch (it screws into the plate that is removed). I don't see a locking collar, but I assume it is inside the to the right (toward the driveshaft)?

 

[Damcowboy]

In the image below number 11 is the actuator assembly and 13 is the shift fork. So I guess in the picture in my post above the down arrow is pointing to the screw hole where a bolt goes (the bolt has been removed in the above picture) that secures the shift fork to the actuator rod. So theoretically if I push the shift fork to the left (toward the tire), assuming the fork moves, the locker should be disengaged. I think. I could be wrong.

 

[Damcowboy]

16 I assume is the sensor switch you referred to that screws into the plate (15), that has been removed in the picture above with the down arrow.

 

[ppc]

yes 16 is the sensor, 14 is locker collar.

 

[Damcowboy]

OK, I'll try to move the shift fork and collar tomorrow. If that doesn't work l'll take the diff cover off and try to disengage the locker through that side. If the locker is already disengaged then I'll know for sure something else is going on, as you suggested might be the case earlier.

 

[mudgudgeon]

I also think there's other things to look at before you mess with the lockers.

Jack both rear wheels up, leave trans in park and transfer case in gear.
Try to turn one wheel, if the diff is locked, you won't be able to turn the wheel. If it's unlocked the opposite side wheel will rotate in the opposite direction.

If the front was staying locked, you won't be able to steer it on hard paved surface.
Getting out of your driveway would be a chore.
If the rear is staying locked, you'll hear the rear tyres skipping and skidding as you turn on hard paving, and it'll be hard to steer in general.

Siezed VC in the trans case would explain the tire shifting as you jacked it up.

 

[Damcowboy]

OK, when I jack up both rear tires, leave the tranny in park, the transfer case in H, turning one tire in one direction, the other tire does turn in the opposite direction. So the diff is in fact unlocked. I don't really have any trouble turning, I know what a locked front feels like when you turn and it is not doing that. Also I did the same check on the front tires as I did on the rear, and the tires do rotate in opposite directions.

Sooo, sounds like the lockers are functioning properly then?

I had a leaking rear main seal and I brought it to a transmission shop for them to pull the tranny and transfer case to replace the seal. When they did that could they have done something to the transfer case to mess up the vicious coupler? I dont know what that is so any help on a path forward would be great. I'll start researching what that is in the meantime.

 

[mudgudgeon]

Viscous coupler uses silicone oil to act as a limited slip diff in the transfer case so you always get some drive to the rear drive shaft. (Similar concept as the engine fan clutch)

They can sieze on failure which means the centre diff in the transfer is not able to do its job when you're turning while driving. You'll get some driveline binding while turning which should release when you straighten up again.

It's a wear and tear item. Not really something the mechanic could muck up

 

[ppc]

@Damcowboy Yes, as I expected. Lockers working but with a failed viscous coupler. Somewhat of a common problem as our trucks age. The viscous coupler is an expensive part new but a used part could have a short lifespan. Most guys just remove it and don't look back. Removal is well documented in a few posts made several years ago.

 

[Damcowboy]

OK, thanks guys for all your help, if nothing else I know a lot more about locker actuators now.

There is a pretty detailed thread on removing a vicious coupler by MikePL back in late 2006, but all the pictures are now red X's. I'll keep looking for a method of removal with some pics and try it myself.