312-8 drive belt idler

[persof 14]

I replaced the drive belt on my 1988 312-8 and it looks like a piece on the top of the idler pully assembley pinches the drive belt wen fully depressed. Please see the pics using the photo bucket links below. Have I done something wrong?

Thanks

Francis

[Duff 206]

Hi, Francis! You've installed your belt exactly right. That device is there to stop the motion of the drive belt when you depress the clutch so the transmission can be shifted without grinding gears. Our Horses don't have synchro rings in the trannies and thus the gears should be stopped before shifting, especially the Hi-Lo range gears - very easy to bend the shift fork or damage the gears if you change ranges with the machine in motion or the clutch not depressed!

BTW - if that plunger thingy that the tensioner engages when you release the clutch happens to fail (top left corner of your first photo), it's next to useless so I wouldn't waste any money replacing it. In a perfect world I think it's supposed to dampen the clutch travel so you don't pop a wheelie, but I've yet to hear from a member here who thought the device was anything but a POS waiting to fail!

Duff :D

[mowerman1193 42]

I may be wrong but I think that is how it is supposed to go...I did mine that way last winter and so far been fine..

Kevin

[mowerman1193 42]

Hi, Francis! You've installed your belt exactly right. That device is there to stop the motion of the drive belt when you depress the clutch so the transmission can be shifted without grinding gears. Our Horses don't have synchro rings in the trannies and thus the gears should be stopped before shifting, especially the Hi-Lo range gears - very easy to bend the shift fork or damage the gears if you change ranges with the machine in motion or the clutch not depressed!

BTW - if that plunger thingy that the tensioner engages when you release the clutch happens to fail (top left corner of your first photo), it's next to useless so I wouldn't waste any money replacing it. In a perfect world I think it's supposed to dampen the clutch travel so you don't pop a wheelie, but I've yet to hear from a member here who thought the device was anything but a POS waiting to fail!

Duff

I wondered what that plunger thingy was...My tractors are all a little older and do not have the little device

Kevin

[jpmcleod 4]

Boy do I have to go and look at mine. I thought the pulley pushes down on the belt for tension not lift it upward. If yours is correct, then I believe mine is wrong.

[The Toolman 22]

You sure that the plunger thing isn't a safety switch so ya can't start it without the clutch being pushed in? i.e. can't start it in gear while peddle is out?

[mowerman1193 42]

You sure that the plunger thing isn't a safety switch so ya can't start it without the clutch being pushed in? i.e. can't start it in gear while peddle is out?

The switch you are speaking of is partly seen in the first picture..The white square thingy just in front of the pulley in the first picture..You can only see the edge of the switch as the pulley is hiding the rest of it..

Kevin

[rickv1957 73]

Pulley guide looks correct!,Rick

[Michael Bullington 5]

thats exactly how mine looks :D

[C-Series14 15]

Boy do I have to go and look at mine. I thought the pulley pushes down on the belt for tension not lift it upward. If yours is correct, then I believe mine is wrong.

Auto's push down...

[persof 14]

Thanks!

[Duff 206]

You sure that the plunger thing isn't a safety switch so ya can't start it without the clutch being pushed in? i.e. can't start it in gear while peddle is out?

Nope - strictly a damper for the clutch travel. No electrical connections to it. It was the fellows here who pointed out to me that by and large it is relatively useless. Probably another "safety device" WH was forced to incorporate because someone somewhere dumped the clutch too fast and had their tractor go out from under them.

Also, if the damper isn't adjusted properly, the clutch can contact it and not deploy fully causing belt slippage.

Duff :D

[The Toolman 22]

Ahhhhh.....musta been another one of those lawyer add-ons I guess

[Bossman12 1]

I know that these posts are over 10 years old, but I wanted to chime in with a hearty thanks for the info. I have a Wheelhorse 312-8 that I bought used last year. It was in pretty good shape but needed some TLC. Mainly, the transmission belt was not engaging uinless I used my toe to pull back the clutch pedal. I figured that out and replaced the air spring with one from NAPA for about $14.00. That seemed to work for the clutch problem, but then it would randomly throw the belt off of the pulleys when shifting gears or working in rough terrain. I even started to smell burning rubber and found the belt on top of the guard for the idler pulley. The info above regarding the 1/8" clearance for the fingers at the engine pulley showed that the problem was at the belt. The belt was sagging way too much even though the outside dimension was 81.8". It was a TORO belt. I went to NAPA and bought a 6982 belt. It fit with what I figured was the correct amount of tension.... 1/2" deflection up and down at the midpoint on the longest run. The clearance for each engine finger was about 1/8". I buttoned it up and went out to mow. It was doing great until I ran out of gas about 45 minutes later. That's a different problem altogether. My theory is that the old belt had worn down the sides to where it was dropping too far into the pulleys and got too sloppy to stay on when being agressive with the clutch and gears. Thanks again for the great advice.