Woods RD7200 mowing deck problem

[phawes]

I have a Woods RD7200 mowing deck with a problem. When running, it vibrates enough so that stress cracks have formed in the deck structure and the belt shields. Belts do not last long. I believe that this is caused by the idler wheel being out of alignment with the drive and blade sheaves. Placing a straight edge on the idler seems to confirm this. I have replaced the idler-arm-pivot bushing (part #35145), but there is still considerable play (i.e., slop) in the idler arm. Spring tension forces the idler arm to a position where the idler wheel is misaligned. Is there a common repair for this problem?

 

[KennyV]

You should not have a LOT of vibration...
Check for bent cracked blades, loose bolts and tweaked pulleys, especially the drive pulley on the gear box. If something is out of alignment or balance it will eat up belts.
If your tensioner is not free to move you can use bushings and spacers to place things in alignment.
With 3 blades and pulleys plus a long belt and idler(s) there is a lot of inertia to overcome at start up, you should feather in your PTO drive, with engine RPM low, to avoid over stressing things. KennyV.

 

[GIJOE]

Remove the three blades and run the mower at cutting height. If the vibration has disappeared install new blades. The idler pulley is a flat grove pulley and tensions from the back side of the belt and is usually wider than a v-grove pulley. So putting a straight edge across the pulleys will make it appear it is out of alignment, but it is actually just sticking up a tad above (and below) the others.

Joe

 

[phawes]

KennyV-

Thank you for responding. The tensioner IS free to move, but perhaps the pivot shaft is worn because the idler is definitely out of alignment. The entire arm is quite loose even though I just replaced the bushing. Where can I place the bushings and spacers so the the idler is twisted back in place?

You should not have a LOT of vibration...
Check for bent cracked blades, loose bolts and tweaked pulleys, especially the drive pulley on the gear box. If something is out of alignment or balance it will eat up belts.
If your tensioner is not free to move you can use bushings and spacers to place things in alignment.
With 3 blades and pulleys plus a long belt and idler(s) there is a lot of inertia to overcome at start up, you should feather in your PTO drive, with engine RPM low, to avoid over stressing things. KennyV.

 

[phawes]

Joe-

I appreciate your advice. I realize that the idler pulley is wider than the drive v-grove pulley and the strait edge will not intersect. But, the idler is not PARALLEL. The idler arm has excessive play at its pivot. If I lift up the end of the arm under the idler wheel about 1/2-3/4", the idler pulley is aligned (i.e., parallel).

Paul

Remove the three blades and run the mower at cutting height. If the vibration has disappeared install new blades. The idler pulley is a flat grove pulley and tensions from the back side of the belt and is usually wider than a v-grove pulley. So putting a straight edge across the pulleys will make it appear it is out of alignment, but it is actually just sticking up a tad above (and below) the others.

Joe

 

[windy acers]

BLADES ARE PROBILALLY REVERSE THREAD

 

[KennyV]

Can you post a picture of the idler and arm & its attaching hardware... I have seen that deck but do not remember just how it attaches...
I reworked the tensioner on my 7foot LandPride rear finish deck a little before I was happy with everything. KennyV

 

[phawes]

KennyV-

I will take a picture, but it will take a couple of days. The mowing deck in a pasture some distance away from my home. Today, I decided to bend the arm to see if I could get the idler wheel aligned. The lever does not bend, but it does break. So, the picture will show that damage.

Paul

Can you post a picture of the idler and arm & its attaching hardware... I have seen that deck but do not remember just how it attaches...
I reworked the tensioner on my 7foot LandPride rear finish deck a little before I was happy with everything. KennyV

 

[WH401]

It sounds like your problem is that the idler, or some other pulley in the belt route, is out of alignment/or some other type of problem, and that the blades are out of balance, and or either cracked/damaged. Having one of the pulleys out of alignment shouldn't generate enough of a vibration to cause stress cracks in the deck. However, that would definitely cause the belt to be eaten up faster. The deck cracks would have to come from something major as that deck itself is pretty thick. I think most likely you'll find it's the blades. Take the blades off and run the deck empty, just as another poster suggested. That way if nothing else you will at least get one possibility off the list.

 

[have_blue]

The idler rarely causes vibration. Sometimes the idler will seing rapidly back and forth on the pivot, causing a bad vibraiton. That's pretty easy to see, however.

1 or more blads shafts could be bent, pulleys could be warped or not concentric with shafts.

Did you ever try to run it with the blades removed to see if it ran smooth? That's also a good opportunity to peek at the shafts and see if they wobble. Bent shafts will smooth out once the blades are removed, but you can usually see the wobble.

 

[phawes]

WH01-

I have been resisting taking the blades off since I do not have an impact wrench. But, I guess that I should take your and Joe's advice to check that possibility.

Yes, the deck cracks could have been caused by the couple of times that I have hit tree stumps. But, the belt shields have broken away at the bolts several times. I have had them welded twice in the last year. I have two sets of blades that I rotate. Perhaps both sets of blades are out of balance.

Paul

It sounds like your problem is that the idler, or some other pulley in the belt route, is out of alignment/or some other type of problem, and that the blades are out of balance, and or either cracked/damaged. Having one of the pulleys out of alignment shouldn't generate enough of a vibration to cause stress cracks in the deck. However, that would definitely cause the belt to be eaten up faster. The deck cracks would have to come from something major as that deck itself is pretty thick. I think most likely you'll find it's the blades. Take the blades off and run the deck empty, just as another poster suggested. That way if nothing else you will at least get one possibility off the list.

 

[phawes]

Bob-

I can see the idler arm move back and forth. That movement dimininished to about 1/4" after I replaced the bushing, but it is still there. The vibration does not seem severe to me. However, it is enough that my belt shields are being torn apart.

I can tell that the idler wheel is not aligned with the drive pulley. I do not know how to align it. The Operator's Manual says "Shim idler as necessary to align". I have no idea as to how to do that.

I plan to remove the blades to try that.

Paul

The idler rarely causes vibration. Sometimes the idler will seing rapidly back and forth on the pivot, causing a bad vibraiton. That's pretty easy to see, however.

1 or more blads shafts could be bent, pulleys could be warped or not concentric with shafts.

Did you ever try to run it with the blades removed to see if it ran smooth? That's also a good opportunity to peek at the shafts and see if they wobble. Bent shafts will smooth out once the blades are removed, but you can usually see the wobble.

 

[WH401]

When you say "belt shield", do you mean the black covers on either side that go over the entire belt drive system?

 

[phawes]

WH401-

I do mean the black covers on either side that go over the entire belt drive system. Here is a picture of what the vibration has done them.

Paul

When you say "belt shield", do you mean the black covers on either side that go over the entire belt drive system?

 

[phawes]

KennyV-

Here is the picture that you requested.

Yes, the arm is broken. A replacement is on order. Breaking the arm is a result of my trying to fix the problem -- not the problem itself.

Paul

Can you post a picture of the idler and arm & its attaching hardware... I have seen that deck but do not remember just how it attaches...
I reworked the tensioner on my 7foot LandPride rear finish deck a little before I was happy with everything. KennyV

 

[ccsial]

How many hours do you have on that RD7200? Did the vibration start when you hit the stump? That's really something the way it cracked the shields. It must really be singing.

I have a bit over 200 hours on my RD7200 in three years and it is fine. I've never hit anything with it.

Each blade has two bolts and I think they are right hand. Mine come off fairly easy with a hand ratchet. I always put anti-sieze compound on them when I sharpen.

 

[KennyV]

Paul,
"Here is the picture that you requested."
No picture... Your other picture is there. KennyV

 

[have_blue]

Bob-

I can see the idler arm move back and forth. That movement dimininished to about 1/4" after I replaced the bushing, but it is still there. The vibration does not seem severe to me. However, it is enough that my belt shields are being torn apart.

I can tell that the idler wheel is not aligned with the drive pulley. I do not know how to align it. The Operator's Manual says "Shim idler as necessary to align". I have no idea as to how to do that.

I plan to remove the blades to try that.

Paul

The idler arm swinging back and forth may not be due to the idler pulley itself.

Sometimes the belt goes tight-loose as it turns, due to one of the main pulleys being out of round or eccentric. A bent shaft or severe blade imbalance can also make the pulleys wobble, even though the pulleys themselves are fine.

 

[phawes]

ccsial-

I bought the tractor and the mowing deck used. The tractor has about 800 hours on it. I feel that the mowing deck is much older. I know only that the Operator's Manual is dated 1999.

The vibration began gradually. There was no event that started it.

I am girding myself to go out in the blazing heat (nearly 100 deg.) and remove the blades. I am confident that I can do it with my 18" torque wrench. The manual says the bolts should be torqued at 85 ft-lbs. I should be able to easily handle that.

Paul

How many hours do you have on that RD7200? Did the vibration start when you hit the stump? That's really something the way it cracked the shields. It must really be singing.

I have a bit over 200 hours on my RD7200 in three years and it is fine. I've never hit anything with it.

Each blade has two bolts and I think they are right hand. Mine come off fairly easy with a hand ratchet. I always put anti-sieze compound on them when I sharpen.

 

[phawes]

KennyV-

I am again trying to follow the instructions for uploading a picture. See if this works.

Paul

Paul,
"Here is the picture that you requested."
No picture... Your other picture is there. KennyV