Alternator Bearings, Can they be replaced?

[Ciaran]

Good afternoon folks.

I was wondering, has anyone ever replaced the bearings in their alternator?

A few weeks ago, the green waft-o-barge developed an annoying 'rattly skid' type noise from the aux belt area. After much messing around, I narrowed it down to coming from the alternator. Indeed, slackening the belt made it vanish completely. At the time, someone on XM-L helpfully suggested that the bearings had a problem, and should be replaced.
Of course, being upto my eyes at work in more ways in one, I haven't had a chance to look near the car in weeks, and last night I found the noise had returned.

I did attempt to slacken the belt again (though I'm really not sure I've got the correct procedure for doing so), but the noise still happens intermittently every 30 seconds or so, so it seems the bearings definately do have an issue.

My question is, where can you get replacement bearings without having to change the whole unit? I've never seen them before anywhere. If it can't be done I'll just have to change the whole alternator, but I'd rather avoid that expense if possible, as I'm buying a second XM next week!

Any thoughts appreciated.

Cheers.

Ciarán

/EDIT: Perhaps this should be in one of the mechanical sections? Really wasn't sure where to put it....

This post has been edited by Ciaran on April 26, 2007 12:24 pm

[techmanagain]

The Citroen parts lists show a breakdown of the parts for the various alternators fitted to the XM (under the title "engine equipment"). You will have to have a record of your alternator make and model number becuase there are so many options listed.

[Peter.N.]

Hi Ciaran

You used to be able to obtain bearings from auto electrical firms, otherwise, you can take the bearings out and you should find a number on them, quote it to a specialist bearing company and they should be able to supply you. I think I would take the easier route and fit a secondhand alternator . You may be able to keep it going a little longer by squirting some oil into the bearings, or it will eventually probably sieze up.

Peter.N.

[onthecut]

Hi Ciaran.

You'll have no problem getting the bearings from any decent bearings supplier; much more likely is you'll wind up sweating actually trying to dismantle the alternator. Some of them are real sods. Unless you've done your type before, I'd be inclined to find your local auto electrics repair place and let them do it. If it's a long term motor and the original alternator, I'd have them change the regulator and diode pack while they're at it. Failing which, I'd go with Peter's suggestion and look for a decent used one.

Mike.

[bigjohnh]

Hi Cieran,

It is worth trying your local friendly motor factors for a recon unit, they can be surprisingly cheap. I got a recon unit for a MK2 ford Escort for 20 quid exchange with a 12 month warranty.

I know XM's arent as common as Frod Escrots (deliberate mis-spelling but sadly accurate) but you may just be pleasantly surprised and proper shops don't mind doing the research.

Best of luck

John

[Ciaran]

Hi everyone,

Thanks very much for all the replies. While I quite like the idea of saving money by replacing the bearings myself, if they're going to be hard to source or fiddly to take apart, I may just leave it to an electrical repair shop, as suggested, failing that, I'll maybe just go down the 2nd hand route, as mentioned by Peter.
Unfortunately time is something I really don't have at the moment, I have work coming out of my ears, so what I think I'll do is wait until I get the new XM next week, then it won't be a problem if the 2.1 needs to come off the road for a few days while a repair / replacement is done.
At least for once the weather is nice, and I don't mind working outside!

Many thanks.

Ciarán.

[noz]

Hi Ciaran,

As you know the purpose of club-xm is to help each other out with information which would help someone to repair a problem with their XM at minimal cost. Of course there is always a trade off between job difficulty, technical ability and spare time. Each person must decide what solution is best for their individual circumstances.

I agree that the bearing job is fiddly but certainly not impossible. You will need a set of pullers. The bearings are trapped in the end plates therefore the puller should pull the entire plate off complete with bearing. The bearing sould then come out of the end plate reasonably easily. Do this for both end plates. The end plates are usually secured to the body with set screws or in some cases held together by very long but thin bolts running through the body or outside of the main body and secured to each end plate. Just take care that the pullers don't shatter the aluminium alloy end plates. The bearing inner race is usually an interference fit on the rotor shaft.

There's no doubt the bearings will be cheap. They are very small. I'd be surprised if they were more than a few pounds each from a decent bearing distributor. The bearing will have its size and rating stamped on it. Just take a sample along to your bearing stockist and they should match it very easily.

The decision to replace the diode pack/regulator should really be based on the condition of the brushes. If there's plently life left in them then the chances are that the solid state diodes and voltage regulator will be fine. The pack of electronics is 'potted' and pretty hardy. Only a spike from a welder or a short circuit on the output are likely to damage it.

Best of luck.

cheers

noz

[techmanagain]

I have tried the repair 'Plan A' not long ago and was told that with labour costs as they are, the cheaper way was to get a replacement unit. So I was pleasantly surprised when he told me the price and took one down from the shelf there and then (in a manufacturer's box). I know it said on the alternator 'Made in Croatia' or somewhere, but that is where Citroen were sourcing their altenators and starters before all the fighting.

[Ciaran]

Many thanks for that explanation, Noz.

I may be able to give it a try if work calms down by next weekend. Failing that, it may be a replacement unit, as techmanagain has suggested, but we'll see how it goes.

Yesterday I was running the engine, and feeling around the alternator when the noise was occurring. I'm pretty convinced the problem is with the rear bearings, thats where all the vibration and harshness is coming from. Regardless, the unit will need removed and dismantled anyway.
Interestingly, someone I was speaking to yesterday, mentioned that some older alternators had an opening at the rear to allow the bearings to be lubricated. I had a quick look for this, but can't see anything obvious, so I don't know if the facility exists on this particular alternator. Its a Valeo I know that much, but no idea of model number.

Anyway, cheers for everyones help, and I'll post an update on this as soon as I get the time to look at it. Thanks guys

[Ciaran]

Well needless to say I still haven't had a chance to sort this, but I did notice today the sound had got somewhat worse. Upon investigation, I noticed that the long adjustment bolt on the alternator has managed to undo itself and escape!
I did it up thoroughly tight too!

Am picking up the new XM tomorrow, so plan on taking this one off the road for a few days and sorting all the jobs that need doing. Will obviously need to sort a new alternator bolt while I'm at it