Tuesday, 29 October 2013

Transmission clean-up

This week I decided to partially dismantle the transmission, although only as far as removing external components. I wanted to clean the thing up and replace any perished gaskets and renew the CV boots etc. I never had any issues with this gearbox and therefore I was not too keen on fiddling around with the internal mechanisms. As my old man always says: “if it aint broke, don’t fix it!”. Pretty sound advice I reckon! 




I thought this task was going to be fairly straight forward, but I couldn’t have been more wrong! I made a fundamental mistake when I first started taking the car apart by not loosening up the rear drum brake nuts whilst is was all still together. The weight of the car combined with the use of the handbrake would have held the outer drum case firmly in place whilst the substantial torque required to loosen the 36mm nut was applied. It would have been a breeze! What I was dealing with here, however, were a couple of resilient old nuts that would not budge and drum brake casings that were seemingly impossible to fully lock off. I tried a lot of different approaches such as; coating the nuts in penetrating oil. Nothing. 5ft Pipe cheat. Nothing. Heating the hub nut with a blowtorch until it glowed red. Nothing. I then called on the assistance of my garage neigbour and good friend, Tony, in the hope that our combined weight and brawn would break the tight bound. NOTHING! So, after a lot of tea and head-scratching, Tony suggested that a small cutting disc attached to the Dremel could provide the solution.  Basically, this sacrificial approach involved making a careful cut down the edge of the nut(s). I tried to make it as deep as possible whilst avoiding damaging the thread underneath:
 

I then repeatedly impacted the incision with a heavy duty chisel until it cracked open enough to come free:


Success! Obviously I now need to order a couple of replacement hub nuts, but I was just glad to get these old things off:


The other noteworthy challenge that I encountered after removing the drum brake components was how to remove the snug fitting rear wheel bearing. I didn't have a bearing puller, so tried to make my own improvised version based on the instructions in John Muir's book 'How to Keep Your Volkswagen Alive'. I soon got frustrated with that approach and opted for the big hammer technique instead:


After a few confident taps on the back of the outer axle tube the bearing slowly worked its way loose:


I was then able to remove the big inner circlip (that was another fiddly job took a while!) and draw out the axle rod(s):


To begin the clean-up of the casing I scraped away most of the greasy dirt with a large flat-headed screwdriver. Then I moved on to degreasing it with petrol, an old toothbrush and a lot of elbow grease. I then went over the whole thing with an assortment of wire brushes. Here is the before shot: 

  

....and many hours of scrubbing later, here is my glorious after shot: 

 

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