A SMEAR all over the shaft, thread and the bore of the new pulley. Basically every where yours looks rusty now. Tony
I've only ever used copperslip on threads as I thought it was meant to help undo the nuts in years to come!
@Bertie the Bus, You assemble parts with a smear of grease to stop corrosion on the faying surfaces, otherwise you risk ending up with the parts permanently rusted together. Looking at your picture of the shaft it seems to me that the back of the pulley was not touching the flange on the shaft as both the shaft and flange are covered in surface rust. Have a look at the back surface of the pulley and see if there are witness marks where it should have touched the flange. I don't think the pulley was on the shaft far enough when it was assembled. Tony
Is this the new "what oil" thread ? Anything on your shaft to stop it rusting, but I'd echo @Lasty : don't put anything on the shims, or it'll "squish" between them and the whole lot will come loose again. Right pulley, clean shims and the nut torqued up properly and it should never come loose. <edit> Ditto with driveshafts...
Thanks Tony Not quite sure what I'm looking for but judging by shiny surfaces on here and front of alternator it looks like the faces were touching and rubbing each other ( ooo errr missus!). Can't see how back of pulley could go on any further.
I must admit I can't see what has happened there, the silver graunched surface is what has been rubbing on the alternator casing. The centre of the pulley (rusty bit) should have been butted up tight on the shaft flange and I don't think it was by the look of it. Best thing to do is get a new pulley assy., clean up the rust on the shaft and take it from there. Let us know how it goes. Tony
Your pulley was an aftermarket one. It needed spacer washers between it and the front of the alternator. The alternator also looks suspiciously aftermarket. Make sure the new pulley spins without making any rubbing noises, that assembly must have been quite noisy with the pulley grinding away and rattling around. A proper original pulley has slots in it for tangs sticking down from the top half of the pulley. An original pulley has a round hole for the shaft in the top of the pulley, and does not rely on the flats on the hub of the bottom half of the pulley to drive the alternator.. A proper original bottom half of pulley should be a fairly tight fit on the alternator shaft, and definitely should not wobble when you put it on. Unless your engine had been used on a trike or a baja beetle or beach buggy, there is no way that rain can get in there and cause rust like that , as it is hard for water to reach the alternator in a bus. My Taiwanese chromed pulley wobbled on the shaft and was heading the way yours went.
I am not familiar with aftermarket Alternators and pulley's, if Mikedjames is correct in his post above, it takes the thread right back to my post #6..............get hold of a good secondhand genuine Bosch Alternator, if need be, have it overhauled by a Bosch auto electrician, fit it with good quality pulley and you should never have a repeat of this problem. Tony
Thanks Mike The alternator is indeed a Chinese version as was the previous defunct one. I bought it as an immediate fix to the failed one with a view to picking up an original Bosch one at some point that I can then have refurbed. I am still looking! The pulley is still the one fitted when I bought the camper nearly 4 years ago. All I did was move it from one alternator to the next. No spacers though. I'm guessing the spacer is only going to be 1mm or less as I don't think there is a great deal of thread left for the nut to hang on! Regarding noise, not being very mechanically minded, and relatively new to air cooled VWs I've not known any different - just sounds like a lawn mower I ordered the parts earlier today, so will fit those next weekend to get running again and then continue my search for a Bosch to have refurbed!
If it has not failed then dont replace it. It has also now been "machined" to the point where a genuine pulley will probably fit properly without rubbing anyway.
The correct number of shims is very important. It has been mentioned in previous posts, but perhaps not emphasised that if you don't have enough shims in total (both between the pulley halves and below the pulley bolt washer) the nut tightens up on the alternator shaft end and not on the shims/pulley allowing the pulley outer half to be loose without you realising. Just to confuse things there are at least two different width shim types available in the long history of VW Dynamo/Alternator supply requiring different numbers. Most shims seem to be the later thin sort needing 10/11 I think. Basically make sure you don't have a lot of thread sticking out the end of the bolt when tight.
This may well have been a contributing factor as I don't think there were as many as 10 - maybe 6 or 7. Received a parcel today from Machine7 with my new pulley, 10 shims, a couple of woodruff keys and a new fan belt
PS When you do slap it all back together, check if you can that the fan belt is perfectly vertical between the crank and alt pulleys. If it's cocked, the belt will wear quickly.
I had a similar problem during an epic run-around when i got stuck in Austria for a few days and had to find a machine shoppe to make a spacer to shim out the alternator shaft behind the pulley by about 3-4 mm . That was about 10 years ago and it`s been fine since Dunno why it happened but it hasn`t been a problem since - weird , but hey , it`s a VW right ?? All part of the adventure
