belt squealing

[76ElCamino]

I installed a new belt on my 1980 440 trailfire and after I installed it if you drive it and stop with the engine running the belt squeals like a bastard, it didn't do this with the old belt on. any suggestions i'm new to snowmobiling after a 35 year absence. also is the gas cap on this sled suppose to be vented or nonvented?

[jdrob]

First off what number is the belt? Should be a 1078. Second are you sure its the belt and not a bearing on the jackshaft ?. Keep us posted.

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[ihengineer76]

I don't think it would be the jackshaft if the belt is squealing when the sled is stopped. Did you try adjusting the anti-creep washers on the secondary? You may be putting too much tension on the center shaft of the primary when you are at idle. I believe there is a section in the fine-tuning manual for Deere in Vintagesnow.com. This may help you track down your problem if the belt is correct.

[ljm]

To answer you gas tank question.

The fuel cap should be vented

[JDMIKE8100]

Are the clutch and or secondary drive rusty?

[Greenxcracer76]

Shims on the secondary.

[Liquifire 4/6]

Remove the retaining bolt from the driven clutch. Under the large outer washer, there are what JD referred to as anti-creep shims. Normally, you'll see anywhere from 1-3 of these shims in place. In your case, you will need to add another one or two of these shims. Take a peek in your tool box and hopefully, the previous owner had removed some of these in the past and placed them in there for safekeeping. If not, you will need to source some and they are of rather unique dimensions. You might try a farm equipment dealership and ask to see their selection of machinery washers (some call them machinery bushings). You might find some that are close enough in outside and inside dimensions to work. Machinery washers are generally available in three different thicknesses, but I don't know the exact thicknesses available. Try to get the thinnest ones they have on hand.

PS: Before you reinstall the retaining bolt, position the belt down in the driven clutch sheaves to hold them slightly apart and be sure the keyway notch in the large outer washer is positioned correctly in the jackshaft keyway slot otherwise, you might end up cracking the outer washer when you tighten the bolt.