Drive belt/belt guard rattle

[oilwell1415 563]

I'm not sure if this should have been in the engine section, the transmission section, or somewhere else, so I'm going to ask here.  If my 552 is running in neutral with the clutch in or out the belt bounces off of the belt guard and makes a horrible noise.  Is that normal?  It's done it since I got the tractor in January, but I never really thought much about it until my wife asked me what it was.  Everything works correctly.  No issues shifting and it doesn't do it with the tractor moving.  It looks like the belt is just dancing on the engine pulley and hitting the guard.  The belt seems loose, but I don't have a way to measure it and see if it's the correct length.  I was going to throw a new one at it since it's obviously worn, but thought I'd ask the question first.

[Flat Thunder Channel 178]

11 minutes ago, oilwell1415 said:

throw a new one at it since it's obviously worn, but thought I'd ask the question first.

 

You can adjust the amount of clutch throw on most models.  Try to reduce the amount the clutch pedal moves forward.  Note the belt cover keeps the belt in position when the clutch is engaged. 

[wallfish 18,298]

Check the belt guard mounts. All the holes should have bolts and mount points. The lower "Z" bend type mounts which were welded to the frame are probably broken off and or missing. The vibration cracks the weld off over time and it a common problem

[71_Bronco 1,072]

I'm having the opposite problem with mine. When driving, I have what sounds like a rattle from the drive belt area. However, when I have the clutch pressed in, it goes away.

 

From the outside, the belt cover looks okay, all bolts present and installed. It's on my list of things to look at this coming weekend.

[oilwell1415 563]

18 hours ago, Flat Thunder Channel said:

 

You can adjust the amount of clutch throw on most models.  Try to reduce the amount the clutch pedal moves forward.  Note the belt cover keeps the belt in position when the clutch is engaged. 

 

I'll check that out.  It does seem to lessen if I let the clutch out just a little bit, but then the brake isn't very strong.  I'll probably have to adjust that as well.

 

15 hours ago, wallfish said:

Check the belt guard mounts. All the holes should have bolts and mount points. The lower "Z" bend type mounts which were welded to the frame are probably broken off and or missing. The vibration cracks the weld off over time and it a common problem

 

There are only 4 mounting holes for the guard and they all have bolts and are solid.  Two in the top of the guard, one on the engine, and one at the rear that goes all the way through the belt cavity and has a spacer on it.  That last one was actually loose and I thought that was the problem, but it still does it after tightening.

 

2 hours ago, 71_Bronco said:

I'm having the opposite problem with mine. When driving, I have what sounds like a rattle from the drive belt area. However, when I have the clutch pressed in, it goes away.

 

From the outside, the belt cover looks okay, all bolts present and installed. It's on my list of things to look at this coming weekend.

 

That's what is strange.  With the clutch pressed in the belt is stopped and shouldn't rattle.  But I can see it bouncing up and down on the engine pulley and causing the rattle.  My neighbors probably think my little tractor is going to blow up it sounds so bad.

[wallfish 18,298]

If the guard is all bolted tight then it shouldn't be bouncing up and down especially at the engine pulley right where one of the mounting bolts are. Check under the frame where the trans bolts on. It's very common for that area to develop cracks around those bolts and you may have a problem there.

For best internet diagnosis, post some pictures so we can try and see what's going on

[oilwell1415 563]

14 hours ago, wallfish said:

If the guard is all bolted tight then it shouldn't be bouncing up and down especially at the engine pulley right where one of the mounting bolts are. Check under the frame where the trans bolts on. It's very common for that area to develop cracks around those bolts and you may have a problem there.

For best internet diagnosis, post some pictures so we can try and see what's going on

 

It's not the guard that's bouncing, it's the belt.  When the clutch is out and the belt is tight it's fine.  When you push the clutch in and the belt loosens the engine pulley bounces the belt against the guard.

[71_Bronco 1,072]

Well, found my issue (rattles when driving, no rattle when clutch pressed in). Its from my iddler pulley connected to my clutch pedal. The bearing is shot and the pulley is flopping around. At least it's a relatively easy fix.

[Alrashid2 402]

On 5/28/2020 at 9:48 AM, oilwell1415 said:

 

It's not the guard that's bouncing, it's the belt.  When the clutch is out and the belt is tight it's fine.  When you push the clutch in and the belt loosens the engine pulley bounces the belt against the guard.

Hey @oilwell1415 did you ever figure this one out? My 312-8 just started doing this for some reason

[kpinnc 14,768]

A common occurrence with these tractors is the belt jumping because it needs replacing. Especially true if it sits for an extended period. 

 

Old belts get stiff spots in them, and can wear unevenly. That will make them jump quite a bit. Also as has been mentioned, the idler on the clutch arm will make the belt jump if the bearing is worn. 

[Alrashid2 402]

Thanks for responding @kpinnc

Just replaced the belt last month so isn't that!

 

I'll double check the idler pulley. I need to experiment a bit more but it seemed to rattle when I didn't have the clutch pedal firmly pushed down. If it was pushed down but not hard, belt would not be spinning but it would start banging and vibrating...