Club 80-90 Forums

Just spent the day overhauling the rear diff lock mechanism on my Doka.

It was non functional when I got the pick up so I expected the usual seized up problem with the the diff pull push rod?

As there was no sign of any movement I striped off the actuator servo and checked the free play on the gearbox pin which was only slightly stiff.

with this moving freely and returning back on the internal spring I then noticed the servo was working in the reverse order....with a bit of Syncro Forum Tech searching I
soon got it all re-plumed and working in the correct manner with the servo pin pushing and pulling in accordance to the switch.

Now here is my problem with it all reassembled it does not want to work .......? I can push the pin in easy and the servo will pull it out. there is plenty of push from the servo when it is off the bracket and it checks out ok going on and off with the switch........but it will not push the gearbox pin in on its own even when I rotate the wheels
so it can engage easily???????????

Is the servo unit on its way out or am I losing power through the Vac system even though I've checked it all out and not found anything obvious....??????????

Give us a clue where to check next.............

Check that the roll pin isnt sticking out even a fraction as it will stop the shaft moving.

Check your vac pressure. <I but this is your problem>

Can you operate the diff lock by sucking on the pipe?
If so then you have a vac prob.

If you take off the black pipe to the switch is there a good suck?
They don't need much but need a good ole suck of pressure.

Has the vac bottle got a good seal? <where it enters the bottle there is a rubber that could leak>

Its trial and error but keep trying!