Antony.

I developed a horrendous grinding noise in the motor area recently which turned out to be the A/C compressor bearings (I think). When I went to remove the compressor belt I noticed my alternator belt was not in great shape either so I put on my spare. What seems strange is that I had to go with no shims between the pulleys to get decent tension so if this belt stretches I'll have no recourse. So my question is where do you guys/gals generally end up with shimming a new belt? Lots of shims, a couple or none?

old man neri

I think I am about half and half. Are you sure it is the right sized belt?

Antony.

I'm assuming this one was the right size. It was in the tool kit and looked in decent condition so I swapped it in since the other one was about to fail. I'll go get a new one and see if I end up with more shims in there. There were two shims between the pulleys when I pulled it today.

old man neri

There is a common size out there that is available at most FLAPS that is close to the carrera one. Maybe you ended up with that one.

Can you read the numbers off the belt?

Antony.

It's a continental AV10 9.5 x 710

moto one

As long as the belt is not too tight starting out with no shims is ok, just keep your spare shims on the shaft under the washer, so if you need them there right there.

Mark.

theiceman

I find the numbers of shims may vary with the belt manufacture, and in some cases I remove shims as the belt get worn in. I don't think there is a science to it. BTW in some cases you HAVE to put the spare shims on the outside of the pulley or you will bottom out the nut before it gets tight.

All the best

Antony.

Thanks guys, yeah I moved the spare shims to the outside of the pulley, just seemed strange that what looked like a new belt used no shims. It isn't tight enough to turn the motor over but seems to spin the alt/fan just fine. I'll order some spare belts and try a brand new one later.

3.2SLANTNOSE

Even though it appears to be the correct sized belt, what type of belt is it, V-belt, square toothed, round toothed, etc? The difference in the belts profile will make a difference on how deep it will ride in the pulleys. The wrong profile can allow a correct length belt, appear to be either too long, if it rides too low in the pulleys, or too short, if it rides too high on the pulleys. Good luck!! Tony!

gecc

There are supposed to be a total of 7 shim. I start with 3 between the pulley and the fan. If you don't use enough total shims the outer washer will bottom out on the fan and the pulley move around. It WILL destroy the end of the fan and the pulley.