Date: Tue, 23 Jun 1998 20:18:52 +0100
Reply-To: Don McCallum <trosgol@ENTERPRISE.NET>
Sender: Vanagon Mailing List <Vanagon@vanagon.com>
From: Don McCallum <trosgol@ENTERPRISE.NET>
Subject: Re: Rear diff lock
Content-Type: text/plain; charset=us-ascii
Randolf, here is the info you requested
1. Remove the servo unit. This involves first of all knocking out a 3mm
roll pin which locks the servo shaft into the diff lock shaft (you may
have a rubber boot which you will have to pull back to do this). Then
remove the servo unit from its bracket (2 x M5 screws). Care to pull off
straight or you can snap the end of the servo shaft.
2. Check the operation of the servo by operating the dash control. The
easiest way to check the servo for leaks is to take it off and suck on the
two vacuum pipes!
3. Check the mechanical operation of the diff lock by jacking up both
wheels on one side - try to push in the diff lock shaft while turning the
wheels. It should go in within about 1/2 turn of the wheel - you will
know it is locked because the wheels will no longer turn!
4. Remove the servo mounting bracket, one circlip and 2 x M6
bolts. If the shaft is seized, remove the indicator switch (it just screws
out). You will see that the diff lock shaft runs in a steel bush and the
plunger on the indicator switch bears on the shaft through a hole in this
bush. Removing this switch allows the complete bush/shaft assembly to
move in and out and you should be able to get the diff to lock by pushing
it in.
5. Free the shaft in the bush by gripping the bush with a pair of
vice-grips and turning it backwards and forwards about 1/4 turn while
squirting releasing fluid into the indicator switch hole. Push and pull
on the shaft while doing this (use an allen key though the 3mm hole in the
shaft to get a grip on it). Once it starts to move, things will get easy
quickly!
6. Chances are you will damage a 19.7mm x 1.7mm O-ring near the end of the
bush on its outer diameter. This can be replaced by pulling out the bush
until you can see the groove and slipping the new O-ring into place.
7. Apply lots of grease and re-assemble. Don't forget to line up the hole
in the bush so the indicator switch plunger fits back in. If you can find
a rubber boot to put over the shaft, so much the better. Its also a good
idea to operate the lock on a regular basis to keep it free. Best of luck
- you are lucky, the front one is even harder!
Don McCallum (1992 1.6 Turbo Diesel Syncro, North Wales, UK)
Randolph Feuerriegel wrote:
> Hello all.
>
> Is there any way of telling which part of the rear diff lock is not
> functioning. The vacum servo unit or a seized plunger. I read in the
> archives back on June 10th that Dan from the UK had been successful in
> freeing up the plunger without taking out the tranny. If you are reading
> this Dan, I would be interested to know how you did this.
>
> Thanks
> R. Feuerriegel
> 88 syncro
> Victoria BC