Bought a new JK alternator about 2 years ago, the “ better one “ , I think 70A After about 1000 miles I had a problem when my alt. Pulley stripped itself. @ Busmonkey helped me and I sourced a new pulley in Spain ( pint still owed there ) there was a little scoring damage to the face of the alternator but all seemed ok. Drove about 2000 miles since. Including 100 miles yesterday Today on way to campsite got a very slight electric burning whiff. Van going lovely. Hit a busy junction and she stalled. Turned key and felt like a flat battery. No smell from engine bay, no overheat, battery checked and showing 12.5. Left it a bit , tried to turn over and horrid metal on metal scrape. Unable to turn engine over. Checked alternator and no movement. Had to hammer/ prise back section of pulley off. Alternator ( as per photos ) has suffered by back plate grinding into face, and probably wrecking the winding. So . 1. What am I doing wrong 2. On photo should there be a washer/ shim to keep back plate away from face of alt.? I.e in the recessed groove around the shaft. ( I wonder if this was wrecked when pulley shattered previously ? 3. Bosch are doing an alt for about £360….should I be going for this 55A as opposed to the 70? A I’ve looked at DIY replacement, …should I be attempting it given the mess I’ve got myself in to. nb. The JK alternator was installed by a “ vw specialist” when he installed my VW 1641cc engine ( which has been great) Any pointers appreciated Ps the face of the alternator at 2 o’clock position has virtually ground through to the copper. Pps low loader home
Been a while since I have played with a type 1 alternator but had a similar problem. Seem to remember it was due to poor quality rear part of pulley. The outside one - rear is rear. RHS in pic. They can round out and not sit “snug” If it moves it can flog the inner pulley. If the other part doesn’t engage properly with the keyway it can work loose. Once all this becomes loose it moves back and forth and grinds away on the case. You “could” be ok. Does look like there has been movement on the outer pulley where paint is gone. Hard to see where it is ground. Cheap alternators have crappy bearings. Double check there is no slop in bearings. ideally you want a good condition OG pulley set and not a new cheap soft metal one. Not sure where you can get quality ones now. As long as you don’t have to remove alternator you can do it all yourself. But the front pulley must be fitted squarely over the key way. Make sure the key doesn’t “rock” back. If there is play in the shaft key slot - game over. New alternator. Key should fit tight. No slop. Then do up the rear half nice and tight after fitting the correct amount of shims to get correct belt tension
I have had to shim the pulley out on a stock Bosch alternator with some pulleys but the wear you have looks like either the bearing have failed giving alternator end float or the pulley has failed. I have been through about three sets of pulleys, the main issue seemed to be the bottom pulley being wonky caused the belt to snatch ( if too slack .. snatch .. if too tight then wear rapidly until loose then start snatching) . which then started uneven wear on the belt that made the snatching worse. Then it disintegrated the top pulley - original pulleys have hooks to take the load built in, modern ones attempt to do it all with a shaped hub. Which is only crimped to the pulley half facing the alternator. That crimp can break loose in the end I managed to recover my new alternator (75A , £129 on eBay for unit similar to VW suppliers selling for far more, goes with heated windscreen) when this rocking and rolling opened up the woodruff key slot by 0.07mm which was enough to keep eating the woodruff keys. So I put a key in the slot, and used a centre punch to peen the metal of the shaft around the slot until it gripped the key firmly again. With a new ali pulley (machined so not at all wonky Brazilian) on the bottom ( 2mm smaller diameter needs a 900mm belt..) the snatching has stopped and modern alternator pulleys last more than 200 miles again. Alternator can be changed without dropping the engine..
Yes Mike, the damage was in the past with a failed pulley that damaged he alternator face. I now have a decent pulley and have driven over 1k miles but it seems that the original damage to the alternator has now caused failure. I have ordered the Bosch from Cool Air they reduced the price a bit from £360 to 334 as C&C were quoting £250 ( but vague lead time) C&C also do a shim set to pack out the pulley away from the alt…but I am hoping I don’t need this. So far as removing the alt is concerned most of the info is not type 1 related. Do you know if it can be done without enginevout and exhaust off ? Thanks Dave
As someone who has adjusted/fitted/whatever 101 of these without any failures I can only assume it's the fitting and adjusting but sadly I have zero idea what I do right and others do wrong, but there must be something. It can only really be that either the two halves + shims between and under the nut have been misjudged and do not allow for the firm clamping required (belt trapped between the halves rather than riding it?) so the nut comes loose, or the nut isn't done up tight enough (doesn't actually need to be very tight) So.. Good luck! ,
I agree but double /triple checked it. First fault was the useless gold coloured pulley which obviously had damaged the alternator more than I thought or perhaps just a poor quality one…..who knows.
It's all very well me saying I don't have a problem but I should say how I go about it. You probably do this already but somebody reading might gain something. It boils down to tightening the nut without jamming anything, not in gear, free running everything, though obviously you have compression which seems to be a real help here. So, you fumble it all together to the point the shims cann't get trapped then spanner, allowing it to turn the engine when it wants which makes the belt ride out. Repeat until you know you have too many or few shims or it's just dandy. The belt can't get trapped unless it's too tight, so you get shims right, the nut tightens down as designed. At that point at first I used the slot to jam a screwdriver in, but... that's not great is it? So, heavy-ish hammer ring spanner, shock it tight. Keep you eye on it you'll see when it won't tighten more. If anyone tries this and it ends in tragedy you know what I'd say - you didn't do it right. So that's it. When I read back, everything about that method seems based on slap happy laziness, but I guess it's one time that this actually works, the compression allows a liittle tightening before the pulley grabs the belt hard enough and then rides out as it turns which allows some more tightening and repeat. Sorry if I'm teaching grandma to suck eggs. Though, having seen this a lot (i.e. gouged alternators more common than unscarred) I hold up my hand to seeking out the type of pulley that has the ears and slots instead of the almost round square hole. Belt and braces. They were hard to find though. General thought - a bit loose is the best side to go if unsure about fan belt tension.
There is this. https://www.csp-shop.com/en/engine/generator-pulley-903-109-111-22889b.html?pn=50&cache=1685026043 It would appear that I was seeking out 6V generator pulleys? Maybe not just 6V, the was one on the dynamo of the ratty van I bought but I'm failing to find a picture of one attached to an alternator. Maybe I'm misremembering having them on an alternator. ...which was on an alternator when I sold the van. (hard to see). ...and in the meantime on this one that revved regularly to 6,000rpm.
lol. This is a thing where everyone blames the parts so I'm suggesting a part that might be better while suggesting also that it's not the parts, but it might be. It's quite hot in here but I aggravated my back/trapped nerve doing the head stud so I'm lying around today with cramp in my leg. Happens every time.
I have pieces of one of the pulleys with hooks.. its broken off. I am sure when I got my bus it had a tatty example. Taking the alternator out with the engine in.. 30mm spanner of some sort required.. Remove thermostat so fan housing can be lifted ... Note how much of the thermostat bracket protrudes below engine case for later restoration. Remove carburettor and central part of inlet manifold. Maybe one end casting connecting to a cylinder head if the inlet manifold wont come easily. Remember some manifolds are bolted with a single nut to one of the case sealing studs on the top of the engine.. Loosen bolts either end of fan housing - m10. Undo alternator clamp and push towards fan housing. Remove breather pipe from alternator stand. Remove air hoses. Remove nuts securing alternator stand to engine case. Lever up right hand end of fan housing and prop with a wooden block or screwdriver handle. You dont want it to lean back on the oil cooler when you push the fan housing up.. Try and get the alternator stand out from under alternator, some force may be needed. Some people replace the studs with bolts when it's all apart so the use of force is unnecessary when you do it again.. Now you reach the state in my picture. Undo four M10 head bolts holding fan cover plate . Remove alternator and fan. Now you have to remove the fan. I used a rattle gun on the nut which works but watch out for stored kinetic energy and fingers ... or use a hammer on the spanner against the mass of the fan, or work out some way to grip the fan - the holes in the fan are probably for some special tool to achieve torque on the nut.. Behind the nut is a wavy washer. Behind the fan there are shims. These are the same size as the alternator shims.. Then there is the fan hub with woodruff key same as the other end of the alternator. You may need one or two more shims with a different alternator. Trial assembly and spinning the fan with the fan housing and alternator in place may be needed, with the alternator resting on the stand . Check for rubbing noises and adjust shims as needed..
Thanks Mike for a great explanation. Unfortunately I got to this stage one nut to come off the alt stand but think ( as you say ) it would need a fair bit of persuasion to get it out from under the alternator. So I’ve decided that although I can get to the lower 2 shroud bolts I don’t think there’s a cat in hells chance of me getting the fiddly buggers back in. I’ve popped round to my local Mechanic ( nearing retirement ) but served his time on old Vw’s. His view was “ its far easier to drop the engine .. ( certainly for him ). Photo 2 shows another little problem I’d like to sort before it goes to him…..the hose fitting at the bottom of the thinner exhaust bit ( don’t know the name ) When I pulled the hose off the threaded spigot came with it. I was considering cleaning it all up and , as the thread is mangled using JK weld resin to set it in…..Is this ok, if not then with engine out I will have options. I don’t like cobbling future problems for others so would appreciate views. Thanks to all for the help
That hose fitting must be half blocking the manifold. I'd be looking for a manifold with an original servo take-off that doesn't and points upwards to keep the petrol out. You can see why some people replace the alternator stand studs with bolts... and then probably never have to do this again.
Definitely , As for the hose fitting , I will look around for what you suggest. As a temporary fix could I reduce the length of the fitting and resin it in ?
As @Zed says, you need to do something about that vacuum fitting. It is half blocking the RH manifold. You van will probably go faster if you shorten it (or find a more elegant way of tapping off a vacuum)
The bolts on the fan housing are in slots so they dont have to come out, just loosen. Then you have to rely on a certain amount of give to get over the studs. Double nutting to pull the stand studs didn't work on mine as there wasn't enough room to get two nuts on and tighten them together enough to overcome the stud in the case when you tried to undo it. Maybe the studs on mine were shorter anyway.. The servo hose takeoff does look a bit hacky but 24 hour JB weld glue will fix it.
Last one I did a few weeks ago I got a socket on the fan nut working blind behind the fan housing, if you can get that undone then all you need to do is lift the fan housing slightly to access the bottom 2 bolts on the fan cover. Fan stays in place. Then you can wriggle it all out pretty easily , just move the carb out of the way.
