View Full Version : 152z squealing with blades engaged

10-20-2009, 12:54 PM
420 hours, replaced belts about 6 months ago, and everytime I engage the Pto I am hearing a whining/squealing noise which sounds like it is coming from beneath my feet around the center spindle. This has been going on for about the last 40 hours of operation and cannot figure it out. It seems to squeal a little louder when going into heavy grass and never really stops until I disengage the PTO. I have had replaced all the idler pulleys to no success. I checked the spindles for free movement spinning them without the belt on and the only thing I found was that the center spindle has what sounds like a short slight rub once every full revolution, so before I go and spend money to replace the spindle I was wondering if it could be anything else? I also researched the entire website for the last two hours reading posts but could only find something about the belts possibly making noise and someone suggesting spraying WD40 on the belts, but I would think that would call slippage if nothing else. Any help greatly appreciated.

waters lawn care
10-20-2009, 01:29 PM
I have same mower with 650hrs never that problem.In saying that i have a jd tractor type mower that would do the oppisite on squealing when blades were disengaged had to replace eletric pto clutch.Problem solved post back if you find problem so i can be on look out for other problems

10-20-2009, 01:33 PM
Ok, no problem I will, it doesnt squeal when it shuts down it just becomes a whole lot quieter.

10-20-2009, 06:47 PM
Check the idler arm bushing - it is a cheap insert on the shaft that the idler arm pulley moves back and forth on.
Also, once the deck is engaged prop the deck plate open and spray wd-40 directly on to the top of the pulleys one at a time in an effort to isolate an early bearing failure.
If this doesn't stop the squealing spray the deck belt with belt dressing.
Before anything else though check the belt for signs of uneven wear, same with the pulleys - there will be signs of the uneven wear but use a good flash light or drop light - just don't rely on ambient light for uneven wear marks to appear.

10-20-2009, 09:57 PM
replaced belts about 6 months ago,

Did you install factory replacement belts ?

Spraying anything on the belt will not solve the problem, I had the same problem with a customer's Zoom (twin to your 150). Can you post the full model AND serial numbers off your unit ?

10-21-2009, 09:40 AM
Tks Txgrassguy I will check everything as you advise on Saturday my next day off and post the results.

Restrorob: OEM from the gravely dealer and the model is 992044 ser 2600

10-21-2009, 09:56 AM
Txgrassguy, looking at the deck you are speaking of 12,13, and 32 on the other arm, I did not think of those especially when hitting heavy grass making those spring loaded arms move alot.

10-21-2009, 07:44 PM
Here's a post I made on another board about belt slippage on the Zoom, There are only slight differences between it and the Gravely.

I found out the customer had taken it back to the dealer twice for this very problem, They had told him both times they couldn't find anything wrong ???

With a re-check of the original belt part number and comparing measurments , I re-installed it on the unit and looked everything over again with a magnifying glass.

Knowing now this GOOD used belt had not stretched enough to cause this loose/slipping problem, And with it riding all idler and spindle pulleys in the proper positions, The only thing I could find is not enough spring tension on the idler arm assembly.

The spring coils were nearly completely closed, So I needed more tension on the belt to alleviate the problem. Yes, I could have installed a shorter belt. But, It would have been a aftermarket which would not hold up as well as a OEM. Then the problem would arise again when another OEM belt was installed.

The idler arm spring is attached to the deck via a 3/8 x 3 1/2" large head carriage bolt, I simply re-drilled the deck moving the attachment point 1 1/4" further away from the original position.

I had to replace the large headed carriage bolt with a hex head bolt due to baffle rings around the spindles that are welded to the bottom of the deck pan. I then installed a short bolt/nut in the original hole to eliminate deck blow-out.

With a few passes down the road side in front of the shop 6"+ tall at wide open speed I couldn't get the blades to slow, Only the engine rpm.

This modification gave me what I feel is the perfect belt tension (not too tight) and will now maintain enough tension as the belt does stretch until it really is in need of a new OEM replacement.


I see your Gravely has a bolt on bracket the idler arm spring mounts to, The before pic below shows how this bracket should be mounted now.

By turning this bracket around and mounting just like the after pic will give you more tension on this belt and should eliminate the slipping problems, That is if the belt hasn't been ruined/stretched too badly from running it 40 hours slipping.


BTW, I done this modification 8 months ago and the customer has brought other equipment in since and tells me it's still mowing just fine.

10-21-2009, 09:01 PM
Tks Restrorob great suggestion, I will definitely check this out, I have ran with the same new OEM belt for near 100 hours until it started doing this about 40 hours ago. I dont know if this makes a difference but when I took the belts back off again to check the spindles I really had to use some force to undo them and put them back on because the springs were so stretched and tight, it seems the belt was also tight IMO. When I get into tall or thick grass I am not getting any skipping or anything and the engine does bind down when in this type grass. This weekend I will have time to try everything ya'll are suggesting and I hope I can figure it out. Glad to have your help

10-21-2009, 11:28 PM
when I took the belts back off again to check the spindles I really had to use some force to undo them and put them back on

All spring tensioned belts are hard and require a lot of force to remove/install unless done as below.

From another of my post;

On a deck belt rout it around all pulley's leaving the discharge side pulley for last, You can then pull the belt enough to get it started on this last pulley. Hold it in the pulley with the palm of your hand then grab the blade turning it to roll the belt on the rest of the way.

On the deck drive belt, Rout it around the clutch and any idler then roll it onto the center spindle pulley.

Do a hydro belt the same way by rolling it onto a pump pulley using a wrench on the lower crankshaft bolt, But make sure you start the belt on the proper side of the pulley so the direction of rotation to roll it on is tightening the bolt.

10-22-2009, 08:38 AM
"All spring tensioned belts are hard and require a lot of force to remove/install"

Ain't that the truth, I have done it before like that using the pulley to spin the belt on with the guard off, but you gotta watch your fingers, I will try the blade next time, tks for the tip. I have a 6 foot finishing cutter on a 40 HP tractor that am able to spin the belt on real easy with the pulleys but the gravely has always been a bit tighter for some reason.

10-24-2009, 07:09 PM
Update: Started messing with today and tried all of the suggestions, however it was still making the noise. I removed the spindle from the machine and noticed that it was making a bit more noise than before especially spinning it in your hand. I proceeded to the gravely dealer and spoke to the mechanic, he said definitely the bearings in the spindle. He said they usually will not last long once they start making this noise, but some some do and he said you should have no noise at all when spinning the spindle. Just so happens they do replace the bearings for you, at a charge of course, $80.00, over the price of a new spindle at my dealer which is $139.00. He said everthing else, the actual spindle housing and pulleys, are fine and did not need changing. He did note that if I were to keep and use the old pulleys and remove them off of the old spindle to put them on a new one, I would have a heck of time even with a pulley puller because most of the time in a machine that is as old as mine the key is rusted frozen and they usually will tear up the pulleys getting them off of the old spindle, thereby needing some new pulleys too. So I had him change them out, the bearings, then I put it back on, and the sound is gone, sounds just like it is supposed to now. I think I will now learn how to change these sealed bearings for the future. The mechanic said due to us living in the south where we constantly have to, even though we dont want to, cut wet grass, it causes the bearings to fail from the condensation or water getting into the spindle housing. Normal wear and tear will cause bearing problems but the wet grass or washing off the wet grass stuck to the bottom of the machine enchances the bearing failures. He said Even running the machine for 10 minutes with the blades engaged after cutting or cleaning the wet grass from under the machine like everyone that buys one here is told to do when buying one, will not always cure the problem, water will still find its way into the housing. He told me its not unusual for him to do about three or four spindle bearing changes a day because of our weather here in Louisiana.

I want to thank both of you for the suggestions in trying any fix before spending money for a spindle, but I was also glad that I was able to have only bearings changed without buying a new spindle.

I really appreciate the help.