1986 310-8 throwing off drive belt

[elcamino/wheelhorse 9,355]

This was the second or third problem with the horses today.Just started mower,push in clutch heard a wack and the drive belt had been  throw off. First time it has ever happened . Finally towed it back to the work area outside the shed . Nothing hung up under the tractor  , took the tin off on the side found belt off and stuck behind idler pulley holder. Again can't see anything problem. Finally got belt on went for test ride. Got a 10 feet , happened again. This time removed idler pulley and it is bent in two places on outer edge. I know I need an idler pulley ,but can you think of anything else I should check. It does not have a damper so the clutch does jerk. The pulley on the trans appears ok , but I need to check . I do have a question about the spring on the opposite side of the trans for the clutch. There appears that the spring could be attached in two different holes on the arm. Mind is in the highest hole. I have checked the parts and service manual with a diagram of clutch but it just list the spring without showing how it is attached . If the spring is attached in the lower hole would than reduce the tension on the idler pulley  and reduce the jerky clutch . Any help would be appreciated. 

Edited April 28, 2017 by elcamino/wheelhorse
spelling

[953 nut 55,873]

3 hours ago, elcamino/wheelhorse said:

spring could be attached in two different holes on the arm. Mind is in the highest hole. I have checked the parts and service manual with a diagram of clutch but it just list the spring without showing how it is attached

Is this a tractor you just bought or is it one that the clutch has been operating normally up till now? How old is the belt and is there any indication of uneven wear? Most  have a small heavy wire retainer near the engine pulley and there should be a retainer on the idler that helps stop the belt from rotating when you push down on the clutch, is it in place and slightly ahead of straight up? 

3 hours ago, elcamino/wheelhorse said:

took the tin off on the side

There is a angle iron piece on the bottom on most belt guards, was it in good order?

Let us see the condition of these items please; you know what is coming next .....

[elcamino/wheelhorse 9,355]

I have had this tractor for about 12 years , first time this has ever happened. The retainers are in place top and bottom on the engine. Belt looks ok . there is a retainer on the idler pulley arm and the piece of angle iron ( sheet metal ) is in place , I have ordered a new pulley , belt and spring. The clutch was acting strange in that it felt like it was jerky more that normal.I need to check the position of the idler arm.  I am going to pull tins on both sides and take pictures. The belt was caught  behind the pulley on the transmission and the idler arm for the idler pulley. Will post pictures tomorrow or Sunday . Way behind in yard work and getting the stare from The Empress of the Known Universe.

[953 nut 55,873]

I wouldn't think the spring location is wrong based on years of faithful service. My guess would be the belt is just in need of replacement,

16 minutes ago, elcamino/wheelhorse said:

clutch was acting strange in that it felt like it was jerky more that normal.

Probably just the belt giving up.  Good luck and take good care of the Empress of the Known Universe.

Several of us have gone through spinal surgery and I pray that hers will be successful.

[elcamino/wheelhorse 9,355]

This is here second surgery coming up. First one was Nov 2015 , Nov 2016 back started acting up again , bulging disk below first surgery . We expected a second surgery but not this soon.  Going thru the motion with insurance has delayed everything.   

[953 nut 55,873]

I am coming up on the second anniversary of mine and am still gaining flexibility, will never be as good as prior to the injury but at least I am walking and able to enjoy life again. 

[bizzo15 52]

Sounds like you're having almost the identical issue I'm having with my 1990 310-8, my symptoms started the same way, I noticed the clutch seemed real jerky and then the tractor was slow in every gear.  Got in in the garage and pulled the tins off and noticed the belt had come off and was riding behind the idler pulley.  Replaced  the belt, idler pulley and clutch return spring and the tension seems better but not perfect, still trying to figure out if I've got the problem fully licked or not.  I don't feeling like burning up another brand new oem belt.  Good luck with yours and let us know what your fix is!

[stevasaurus 22,881]

Hi Jim...my horses are older, but sometimes I get the jerky clutch thingy.  If yours was sitting all winter, it could be a little oxidation (rust) on the pulleys and in the grooves.  It doesn't take much for the belt to grab when you let off the clutch.  Solution, clean and shine those pulleys up and wipe with mineral spirits.  Sometimes, I will give the belt a good wiping with mineral spirits also. 

   Looking forward to the pictures to see why it is jumping the idler.    I wonder if the jerking could be causing the belt to jump.

[elcamino/wheelhorse 9,355]

@stevasaurus This was the third time I had the 310 out for mowing. Two previous outings worked fine. Took today off to let arms heal some. Old guy on 51mg Aspirin equals bruises on both arms from pulling tin, getting belt from behind pulley and other. Maybe I will take picture  of arms first. My neighbor is working today so I have to wait until tomorrow so he can help push the 310 in the shed.

[elcamino/wheelhorse 9,355]

For those who like to make fun of old men and their problem a couple of pictures for your enjoyment . The results of removing tin and stuck belt. First picture is left arm reaching under fender and pulling on belt , second picture is right arm from everything. Expected some sympathy from head of household but she just shook her head and gave me the look.   

[squonk 41,413]

You got little ones. I get them from just walking thru air. Maybe at the show we can play "Top This" 

[953 nut 55,873]

1 hour ago, elcamino/wheelhorse said:

Expected some sympathy from head of household

                                                                                          

[stevasaurus 22,881]

It is amazing how easily we bruise as we get older.  You should see my arms after playing tug of war with the puppy.  BTW, we bleed easier also.  I like to pick scabs, so this is not a problem.   

[squonk 41,413]

I was playing tug o war with the big hound. He really likes to shake the rope. My right bicep got all purple. This was 2 month's ago. The bruise is gone but it's all I can do to hold a cordless drill with my right hand. Arm feels shot. It's getting better but it's tough to go to work everyday down a wing. 

[elcamino/wheelhorse 9,355]

Now that the funny comments are over , back to the issue of the belt problem. I went out early morning before it got way to hot and humid. Removed the tins and foot rest on both sides. Put the defective pulley on to show the belt. I think the belt is stretched are that caused the problem . Please look at the attached pictures and let me know what you think. I have not checked roll  pins . I did not see a lot of rust on the pulleys and the trans pulley is on correctly.

[953 nut 55,873]

Were we getting  ?

            Looking at the photos I would think a belt and idler should get you back on the lawn for another thirty years. 

[elcamino/wheelhorse 9,355]

@953 nut I hope that those items will fix the problem. It needs a good cleaning and paint on all the tins and foot rests. The parts are scheduled to arrive on the 4th so I should be able paint all of the tins. I plan on cleaning as much as possible. I want to replace the front spindles with 8 inch spindles with correct rims and tires , but not sure if I will have time. 

[elcamino/wheelhorse 9,355]

I got off topic with the photos of my arm bruises and then the Peanut Gallery had to tell their stories of bruises. I wonder if @squonk gets bruised setting on the bench at the Big Show waiting on a ride to New York ?

[bizzo15 52]

In that first photo is the clutch pedal depressed?  I ask because it seems like the idler arm and pulley are way far forward as if the clutch is depressed, if that's not the case that may be your problem right there but I'll let someone with more experience wrenching on these weigh in. 

[1995 520H+96+97 937]

The tractor is missing engine mounting plate and bolts.

[stevasaurus 22,881]

Jim, in the 1st photo...is that piece of metal that sits on top of the idler pulley adjustable...in other words, can you close that gap a little?? 

[elcamino/wheelhorse 9,355]

@bizzo15 I had the clutch pedal tied down with a piece of rope, made working on it easier. @1995 520H+96+97 to my knowledge 1986 310-8 does not use a mounting plate and two of the mounting bolts are under the frame. @stevasaurus Never tried to adjust the gap but may take a wack at it when I start putting the new parts on it. I need to do some clean etc, so I will take look at it then. Don't want to been something and break it.

[bmsgaffer 2,045]

I am with @stevasaurus. YOur idler pulley guard should be flat (parallel) with the top of the belt, and I think it should even be a little hard to get the belt to fit in between it and the pulley. If that guard stays angled like that, as soon as you push in the clutch, that flap will push the belt right off the pulley. 

 

My theory is that the first occurrence was a fluke, (bad belt, etc who knows?) and then after that it will continue to happen due to the damage caused by the first time. That belt will come off pretty violently if it gets pinched by something then yanked on by a 10HP kohler. 

 

Also be sure that your belt guard has that little tab on top up by the engine still that helps guide the belt when the clutch is pressed. If that tab wore away then I could see the engine grabbing the belt when the clutch is pressed (and thus yanking it out of the idler pulley damaging that little top guard on the clutch pulley)