(Home) seized alternator

Not a good day today. Had the Christmas tree syndrome a couple of miles from leaving home. Drove on a couple of hundred yards to get off the main road and was leaving a trail of burning rubber smoke behind me. Not too nice inside either. When I opened up the seat to take a look the two fan belts were burning hot and the alternator had clearly seized. I called out the AA and when he came I switched it on to show him and now the fan belts weren't even spinning because the crankshaft pulley had sheared at the little rubber bit joining the outer and inner. Looks expensive.

Now most of this is straightforward to do if a bit of a pain but is a seized alternator something that can be cured by reconditioning or should I just accept that it is knackered and get a new one.

- (#282) Jim Tang, 22 Mar 05 14:32

I guess the answer to that one is, you don't know until you strip it down and see what the extent of the damage is from the heat. At some point in the investigation it may become apparent that it will be more expensive to source and replace components rather than replace with a recon. Fingers crossed it's superficial.

- (#282) Ian Dunse (Derbs), 23 Mar 05 01:32

Well, unless you facy having a go with the silicone rubber option, you'll certainly need a pulley. But the alternator? Probably fixable, and if you can remove it yourself, you can likely repair it yourself too. Remember that the alt. is comprised of two units bolted together- the alternator itself, and the vacuum pump in front of it. Either could be the problem- broken vane in the pump, or a collapsed bearing in either bit. Likely a tenner for a part but a days work to sort...

- (#282) david miller, 23 Mar 05 01:43

Pulled out the seat today and had a closer look. It is amazing how much consequential damage can come from what seems to be a seized bearing. The friction from the two belts rubbing on the stationary alternator pulley seems to have almost melted the belts nad covered the front of the engine in a mixture of powdered and melted rubber gunge. When I left it to cool this rubber then resolidified and baked onto all three pulleys: the alternator, crankshaft and fan. It set so hard that when the recovery man started it up to have a look, these bonds were stronger than the rubber inside the crankshaft pulley which then itself sheared. I guess that means that it was on its way out anyway but it is still a real pain since if the recovery man had just taken my word and not started it up I might not be facing such a big job.

Anyway, the crankshaft pulley is clearly borked. Covered in molten gunk and if I could clean it I would then have a huge gap to fill with glue and I aint that confident of finding something suitable.

The alternator is a different kettle altogether. The vacuum pump seems to spin quite happily and it looks as if the bearings inside the other half have gone. I will investigate further but for now it is standing upside down on a bit of old newspaper; it may only contain a teaspoon of oil but diesel oil can make a big mess in small quantities. A sort of reverse Tardis effect.

Now the engine manual mentions replacing the bearings and makes it sound quite simple. Just remove the felt carefully etc. It doesn't however mention any part numbers. Is this one of those jobs that is theoretically possible but in practice you can only buy the bits in batches of a hundred, and the bloke doing it on his own needs to find a friendly repairer and beg to be allowed to buy one, or are there recognised sales outlets for these bits. In which case can anyone name one or two.

And let this be a warning. Never ignore the Christmas tree, even for a few seconds.

- (#282) Jim Tang, 23 Mar 05 14:13

Bearings? take a note of the number inscribed on them (be like 6201-2RS, that's the format. If not, measure them and I'll tell you what they are ;-)) and go to your local engineering suppliers. Couple of quid each...

- (#282) david miller, 23 Mar 05 14:42

While travelling in a beautiful hot wet tropics my litace van when turned on demister dash lights went out, no lights & alternator light came on.
Got dash lights etc working again but alternator light will not go out. Any suggestions is much appreciated.
Thanks Shorty

- (#282) Doug Thompson, 8 Apr 05 06:48

I had strange things happening with dash and warning lights. Found the problem to be battery terminals. Give them ALL a good clean, not just the main posts, but the smaller cables connected to the posts too. If that don't work check to see what the voltage across your battery is, with the earth lead off (should be something like 12.5V) and then again with it running (approx 14.5V). If they are ok, you'll have to start looking at wiring/fuse connections etc.

Note: Just in case you don't know, for safety always disconnect the earth lead first, and connect it last (stops you accidentally causing a dead short with your spanner).

- (#282) Stewart, 8 Apr 05 17:56