winch dog clutch

[4x4-581]

Has anyone had problems with the winch dog clutch?
The air ram seems to be operating okay, but the arm going into the winch seems to be seized.

[Mick_Marsh]

Sounds similar to a problem with mine. It won't disengage to run the cable out. It has to be run out with the motor.

[4x4-581]

I have been doing the same, its time consuming though running the winch out with the motor.

The dog clutch must be seized, i have attempted to top the winch up to the brim with engine oil, kero and diff oil hoping it would soak what ever is stuck and perform a miracle. When i have finished using the winch in a couple of weeks or sooner im thinking i will have to remove it from the truck to fix it.

Is there only one grease nipple on the winch?

[zulu delta 534]

Try hooking the winch up to another motor vehicle, drive and pull the winch out keeping some pressure from the connected motor vehicle applied (Not too much- a bit of common sense needed here) and whilst it is under reverse load hit the winch clutch one or two times.
This should do the trick.
Running a winch out under drive is not really a good idea as you are driving against the winch braking system.
The solution is to use the winch a bit more often. The pin (dog clutch) tends to "grow" with inactivity and jams itself in place. It was, in hindsight, really a backward step going from the Studebaker's mechanically operated clutch to, what was then, a newfangled air operated system. About the only backward step in that transition though I might add.
Best of luck
Regards
Glen

[Diana Alan]

Still even with that minor issue the Mk3/Mk4 were vast improvements over the CMP Blitz trucks of their original design.

[Bluebell One-eight]

As the master says lack of use is the cause. The strange thing is that a "cure"will work on one occasion but not another. The air ram must have at least an inch of travel to disengage the clutch, any less and it won't.  Sometimes a little help with a brass drift and hammer will work. Common sense again is the order. Tap the clevis in the direction of travel, and it may solve the problem. Always make sure that the cable has no tension on it when attempting to disengage the clutch. If this doesn't work along with Glen's procedure, select neutral on the transfer case and turn the drive shaft by hand, and have someone "rock "the winch drum by hand (with gloves on) It may take several attempts with each of these procedures for success. Engage and disengage several times... It might seize again, and test the patience, but only reasonably regular use will keep it free. If it won't free then dismantling it will be necessary..shudder. The Mk4 I have was the same and the rocking procedure worked then it wouldn't disengage after use so the knockometer was tried and worked, even though it was unsuccessful the first time. Good luck

[Alien]

Sounds similar to a problem with mine. It won't disengage to run the cable out. It has to be run out with the motor.

This has got air going to the ram but it's siezed and won't move.
Once a locating pin was removed the lever could be moved.
One more thing for the list.

The pictures I have show 2 grease nipples on the winch too.

[4x4-581]

I tried the tugging of the cable attached to the landcruiser, then tried the knockometer and that worked brilliant. The dog clutch worked a few times though as it should from the cab but then stopped working. guessing it needs a few more hours work.

[Bluebell One-eight]

I tried the tugging of the cable attached to the landcruiser, then tried the knockometer and that worked brilliant. The dog clutch worked a few times though as it should from the cab but then stopped working. guessing it needs a few more hours work.

A little penetrating oil in the ram ports might help, after unscrewing the hoses. If it has stopped behaving it might be that the drum has rotated a little. If the dog and drum are not aligned then it wont engage. It seems to do the same when disengaging, if you turn the drum by hand the dog should move with quite a loud "clack" . If this works  then all is probably OK. If the clutch doesn't engage when required even pulling on the cable should work. If the drum is full you might need to pull out about a metre to let that happen