Diff lock binding

[Imagery]

I am posting for a friend who has a 1998 100 series Landcruiser. I own a 1997 80 so usually I am on that forum but figured this would be the best place to ask about his problem. They are the original owners and the vehicle has not been used off road probably ever. He said the other day when he got in to drive, it felt like the diffs were locked and could not make normal turns because he felt something might break. He said the DIFF lock button was not engaged nor was the indicator lamp in the dash. I don't know anything about this vehicle as far as its maintenance schedule but I am sure that nothing has been done except for the normal oil changes and brake service. He did mention that he thought the brakes might need new pads because he can hear them making noise. I think the vehicle has close to 200K but all highway and city driving. I told him I would get on here and ask if anyone might be able to help point him in the right direction on this issue. He cycled the diff lock switch and it did not seem to do anything but it just felt like it was binding when turning on the pavement. I didn't know if it was possible that somehow that diff lock had engaged due to failure somewhere in the electrical system, or it might be something completely mechanical such as CV's or something in the transfer case or rear diff. any suggestions would be helpful so he can get it repaired by qualified mechanic. They could take it to the Toyota Dealership I imagine and they could locate the problem but we just wanted to have a better idea of what night be going on before he takes it to dealership and they start replacing parts.

Thanks,
Mark

 

[AndersNO]

1st, if something is really bound up/locked, advise your friend not to drive it around on pavement, as the stress on a locked drivetrain on high friction surfaces is immense.

If rear lock is on, you will _really_ notice drivetrain binding up on pavement or any other solid surface.
If problem is cv joints it will mostly be clacking noises up front when cornering (especially full cornering at low speed).
If rear brakes, it will be well... braking, and eventually noise/warm rear brakes.

If unsure where the problem was i would first lift it up so that all four wheels was off the ground and check what excactly was binding / locked.
-transfer case in neutral.


If rear diff:
-Unplug connector on rear differential lock actuator (small unit located on the differential housig).
-Try to turn the rear wheels a little by hand, if the problem is electric the lock should now go off.
-If not, remove diff lock actuator and try to move the shift fork for the locker by hand/screwdriver etc. (also turn wheels a little to avoid binding).
-Shift fork moves correctly and engages / disengages lock = differential OK, actuator faulty.
-Shift fork does not move = something wrong inside differential.

Check actuator and electrics:
-Plug connector back in while actuator is removed from differential.
-Turn diff lock "on" on switch inside vehicle, with ignition on and transfer case in Low range.
-Actuator should now move.
-Turn diff lock "off".
-Actuator should move oposite direction.
-If nothing happens check voltage for actuator. If ok the problem is inside actuator. Open and inspect.

In "rusty" enviroments the actuator to corrode and start to leak water and seize up internally on 10+ year old vehicles.

If transfer case:
-check center differential actuator.


If front wheels:
-Check driveshafts/cv joints.
-check front differential.


I'm sorry i cannot help you with more detailed information on where/what to measure on the electrics, but i am currently working in Angola and didn't bring my LC100 schematics

My best bet if things are the way you describe, depending on how good your friend is to diagnose:
1. CV joints worn out.
2. Rear brakes or parking brake stuck.
3. Rear diff lock actuator stuck in "on" position.

 

[Imagery]

thank you very much for taking the time to make suggestions as to where we should look to find the problem. You gave very helpful information and a good troubleshooting procedure to help isolate what is causing this to happen. If I could drive it myself, I might be able to have a better feeling about what is going on since it must be very similar to my '97 80 except for the front independent suspension and cv's. Part of it could be caused if several factors or service procedures have not been done like it they ever drove it through flooded street water and got water inside rear diff or just from non use of the low range section of xfer case and not using the diff lock before. I will keep this post updated as we begin to troubleshoot the vehicle and eventually find the problem. Thank you again for your time, you have offered excellent advice.
Mark

 

[AndersNO]

No problemo, im just hanging around the office for 12h a day waiting for a flight home....

The 100 drivetrain is very similar to the 80, except:
-independent front, instead of a solid front axle with cv joints in each end you have "loose" axles with one cv joint in each end between the differential and wheels.

-Transfer case; in the 80 you have a viscous coupler. The 100 has an open differential with locker.

-Rear is very similar.

When fixed, and no matter if it was a locker or diff/cv/something else recommend to your friend to take his/her 100 out on a patch of gravel or some other loose surface a few times a year and use low range and all lockers, this to prevent them from seizing up.

Mechanical stuff that isn't used - get's stuck. Law of nature.