Why is my 200Di eating alternator belts???

Tried asking this a while ago in General Land Rover Chat, but didn't get anywhere, so, lets try again:

My 200Di engine eats alternator belts, I have a belt from the back pully from the crank to the alternator, then, the front pully from the crank goes to the water pump.

Runs fine normally, but, then, often after hard work the alternator starts squealing, if you look in the engine bay and rev the engine you can actually see bits of rubber coming off. The squealing will then stop after the rev's are up a bit for a while, then start again when low again, and so on.
Eventually it snaps.

I'm running an uprated 300tdi alternator, with the original 200tdi pully on it.

It would suggest something is maybe slightly out of align? But, not always?

Is that back pully actually in line with the alternator? I know it's designed for Air con and the alternator should be off the PAS duel pully - but - I don't have PAS (yet)

If it is a possible minor alignment issue I was thinking I could get the second alternator kit and just move my alternator to where the Air Con pump would be...


Or, I just keep buying lots and lots of alternator belts!!!

The glencoyne site says spacers need to be fitted to the series alternator bracket when doing a di conversion. Are you sure these have been made correctly?

Yeah sounds like a misalignment issue, could just be slightly out and so when the belt warms up through rubbing the rubber becomes Softer and breaks off easier then burns through the belts, is the pulley smooth, does it wobble ?

Alternator is only a few years old and no play in the bearings.

Interesting that glencoyne suggests using spacers and the series bracket... i don't have the series bracket anymore, so, that's not an option, but, it does strongly suggest that the pully isn't exactly in alignment, otherwise I assume he would have gone with my method?


Think i might go with the plan of a second alternator mounting kit and just move the alternator all together.

I am with all the others on an alignment issue. My series 3 diesel with supposed standard fittings had an alignment issue. When people mess about with things and say fit an alternator from a different car and a VW Golf pully or some other bodge it all tends to go Tits up try and use a steel rule as a straight edge and check it out. You mention a pully off another vehicle is the diameter correct?

have you thought that it may be the fact you're using the aircon pulley to drive the alternator??

the aircon pulley is a fair bit bigger than the front pulley thus when you rev the engine it tries to accellerate the rotation speed of the alternator faster than it should, giving that poor little vee belt an awful lot of gyp trying to transmit the increase, a way of solving the problem would be to find a larger diameter pulley to fit on the alternator, thus reducing the stress on the vee belt

no idea if you'll find a bigger pulley though

The profile of the pulleys may be different, they could have been designed for different types of belt, some have a smooth "V" cross section, some are segmented with a flat edge.

Start at the beginning ... Have you checked the belt tension?

Hmm, some interesting points there.

Having looked at the Gwyn Louis site for the second alternator, it uses a wider V belt than I use... suggesting that the air con crank pulley is designed for a wider belt than i'm using.

The pulley is from the original 200tdi alternator, so, i don't see an issue there, i just use a 300tdi alternator (which would have the serpentine style pulley by default)

As there are kits to put a second alternator on, I wouldn't have thought the size of the crank pulley would be an issue... other than, again, the size of the belt i use.

SO!

Do i go with a bigger pulley or splash out on a second alternator mount kit??


Oh - and tensioning is fine... well, it's tight... in fact, the water pump one is really rather loose by comparision, yet, that works fine!

You should have between 1/4" and 3/8" (6mm - 10mm) free movement on the 'long side' of the belt, otherwise you will chew it up!

Oldseadog said:

You should have between 1/4" and 3/8" (6mm - 10mm) free movement on the 'long side' of the belt, otherwise you will chew it up!

Click to expand...

really? ouu, thank you, i'll try slackening off the alt. then and see how that goes.