Really knocking and banging...

[Helga]

Hi, there has been a loud thumping and banging from the back of my 82 Aircooled T25 recently, I though it was something vibrating but couldn't find anything loose... however it seemed to be coming from the alternator belt area, so I tried tightening the belt but can't get it that tight... might be that it is worn... anyway I took it off and briefly ran the engine, it was still a little rattly, but not anywhere near as bad as before, so, do you think it IS the belt loose? Or do you think the pressure of the belt might be shaking something else? Does the fan housing on the engine have bearings that could make that noise? Or the alternator maybe... weird.

The engine does usually make a lot of noise though! Aircooled for you!

Thanks. Helga.

PS... how can you get the belt REALLY tight?

[Mushr00m]

Your alternator belt shouldn't be too tight but as they normally squeal when loose, I'd say your's isn't. What it could be is the exhaust knocking against something, a.n.other part rattling or more alarmingly your big end bearings are shot!

I'd certainly check out what it is before restarting the engine & if you can't find anything loose around the area of knocking/banging, then drain the oil & check for silver flakes of babbit(lead/tin) metal in the oil.

I have a wbx & they have a cowling protecting the water jacket from road debris under the engine that started rattling, it could be something like that. Just don't go driving your van until you at least discount the worst case scenario of the big ends first.

Best of luck.

[Helga]

Hmnnn. unfortunately I read your post AFTER a 15 mile drive to my closest Aircooled friendly garage! Never mind, it seemed to perform fine, simply with the added benefit of banging and vibrations... the mechanic, an oldish bloke with a yard full of VW bits (good or bad sign?) said it is the alternator. He told me this on the phone later, and said that since they don't make them anymore for my 82, he has sent it off to be reconditioned, but should be back tomorrow... now stupidly I never asked for a price... and am a little worried now: how much should a reconditioning cost?! I have seen a reconditioned ones on JuskKampers for 140 quid... plus, can they really do it by tomorrow?!

Christ, how I hate the worry and frustration of using a garage!!

[Helga]

Anybody have a price?

[phade]

It may also be worth trying to find out how much it would cost to get a new one from VW Classic Parts Center http://www.vw-classicparts.de" onclick="window.open(this.href);return false; . It won't be cheap (if they have an alternative part number for the alternator) but you will know that you are getting genuine parts.

There's also The Bus Depot in Blaine, Washington USA. They sell a reconditioned alternator part ref # AL114XOR which costs $159.95 + shipping + import duty + VAT.

There were two different types of alternator fitted to non-fuel injection Aircooled engines, which are as follows:-

45 Amp Alternator: 070 903 023 D (original part number, no longer available)
65 Amp Alternator: 070 903 023 E (original part number, no longer available)
Alternative 45 Amp Alternator: 070 903 023 CX (not found on http://www.vw-classicparts.de" onclick="window.open(this.href);return false;)

Alternator repair kit (check to see if it will fit your alternator): 020 903 320 B (not found on http://www.vw-classicparts.de" onclick="window.open(this.href);return false;)

Good luck with finding a replacement alternator.