differential lock servo

[dave friday]

Hi all,the "Bentley" book says that the servo can be removed [after removing the ind switch/] mine comes out so far then stops any advice/ideas?
ta.

[Aidan]

er rollpin locking it into the shaft ? There's a three mm rollpin to punch out and recover or lose depending on wether you have a magnet or somesuch to hand.
If it's a late one with the rubber boot in two parts joined by a plastic band seperate at the band so the short side is on the case side and you will see the pin hole and can punch it out. If the boot is not split then it will be necessary to compress it slightly against the case to get to the rollpin.
Be careful if you bend the pin of the vacuum unit it is likely to snap - £40 for a new one these days .
Is this a case of it doesn't work so you are trying to free up the shaft/sleeve ?

[cranman]

i used a small drill bit to tap it out being carefull not to hit it too hard but getting that rubber boot out of the way is a wee bit tricky replaced it with the rubber boot from a clutch slave cylinder i had lying around that is consertina shaped just made things a bit easier putting it back togther.

[dave friday]

Thanks both, yes Aidan im haveing problems freeing up the shaft, it sticks badly when fully out,does the shaft have more than one oil seal?the part of the shaft that i can get to is clean and has no corrosion or marks,ect.
The front diff one freed easily!.

[Aidan]

there's an o ring on the outside of the alloy sleeve that seals it against the case and there's the most expensive oil seal in the world on the shaft itself. There's usully electrolitic corrosion in front of and just behind the seal, also certain chemicals seem to affect the seal and cause it to swell and deform (it's square section twin lipped thing) and become jammed. I recommend using gear oil as the lubricant, in through the tell tale hole and repetative manipulation in and out, with an allen key through the roll pin hole on a late (mid 86 build on) one. Early's with the short pin are a pain to free, they are like the front one, you were lucky with that, when the front is bad it's a diff out job; if you can't free the rear insitu then it's box out time to take the bellhousing off and strip the whole thing and do it on the bench. I have had to ream some sleeves they were that corroded.
They are splash lubricated with gear oil through a little hole with no drain, as the oil becomes cruddier the crud builds up and the lube fails. Salt water seepage from without and it jams solid

[HarryMann]

I believe some don't replace the outer oil seal to allow a small occasional drip to help prevent said corrosion problems. Is that right?

Spring-pin (roll-pin) (3dia. x 10mm) - (Vac Actuator pushrod securing) N 013 294 2 £0-23

Wiki on diffllock actuators

[dave friday]

Thanks all, i managed to free the shaft[i also did it about a year ago!] but its still a bit notchy when fully out, it does feel like the seal is twisting.The vac unit shaft had seised/corroded in the shaft and snapped when i removed it, fortunatley? it was leekey[i used the front vac unit to check diff lock meck!].So i now have to drill the actuator out[its a bugger to get to] and buy a new vac unit.
Still its sunny here so i cant complain.

[Aidan]

just spin the remains with a 4mm drill bit then use a magnet, 9 times out of ten that will draw out the stub, may need a pin to agitate through the roll pin hole

[dave friday]

Yea thats the plan but the cooling water pipes are in the way!!, i might look for a right angle drill thingy or one of those flexi drive thingys, the gear box has to come out at some point to replace the front crankshaft oilseal!, so...?Hopefully one of my VW agents will have a vac unit.

[dave friday]

I think that the reason the front diff mec freed up so easily was because it was coated in white grease [that had solidified]and had the rubber cover on it,the metal work was/is bright and shiny[compared to the back which is dull and matt and hadnt a cover!].Asking for a right angle drill adaptor thingy in Spanish is real fun!.

[HarryMann]

Try magnet and a thin rod into the dowl-pin hole first to try to lever it out a bit, or is it 'solid'

Or a long series bit in a normal battery drill?