Mower belt too tight or too loose?

24696 Views 14 Replies 7 Participants Last post by Bob MacGregor, May 15, 2016

k0jdd

Discussion Starter · Jun 28, 2011

I went to the tech section and I RTFM. :roll:
I did a search of previous posts. :thumbdown:
If the answer is here, I could not find it, and you can all beat up on me. :crazy:

I recently leveled my deck after installing new blades.
In reading the new sticker on the re-painted deck, it said to tighten the spring until the gap is 2x the diameter of the spring coil.

I had always gapped at 1x, but I just figured I was wrong...
Just looked at the K46 manual and it says 1x ! :facepalm:

Mowed today @ 78 degrees outside. :mowlawn:
My OEM belt with about 1-1/2 seasons on it failed. Three of the seven cords came out one side, belt twisted, derailed, overheated, yadda yadda yadda. :facepalm:

So assuming no flaw in the belt, did I more then likely over tighten the belt, or was it too loose? :headscratcher:

I want to correct whatever I did so that Brian H. can't retire on my belt purchases and leave all you guys in the lurch. :mrgreen:

John
(Let the beatings begin...)

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Bob MacGregor

· #2 · Jun 29, 2011

Hi John,
Frequently this problem is caused by a slipping clutch. The heat created by the slipping clutch will overheat and destroy the V belt. Other causes are friction disc worn too thin causing clutch slipping, worn pulleys, pulley bearings dragging, belt incorrectly installed, V belt contacting something that it shouldn't. If you had to frequently readjust the tensioner while mowing then it is heat from something slipping or dragging. I have had an EZ Adjust clutch go out of adjustment while mowing and smoke up a new drive belt in short order. The clutch pulley should be cool to the touch even after the deck has been operated for a while. Of course you need to turn off the mower and shut down the engine before you stick your fingers in and touch the clutch pulley. Look around for belt residue to see what may be the cause. Electric clutch pulleys get hot enough to where you can't keep a finger on it but not enough to smoke up a V belt. J-N decks one spring diameter space, RM decks on 3000-4000 series machines twice the spring diameter for the belt tension, check the adjustment with the deck lowered for mowing and running.
Bob MacGregor in CT :mrgreen: :mowlawn:

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99flhr

· #3 · Jun 29, 2011

I prefer to set per the directions, then start engine . lower deck and engage pto.
I then decrease tension until the belt strand coming off the spring loaded idler runs smoothly without undue movement or thrumming. The spring spacing is always changing when running so I base it off the belt behaviour. JMO

k0jdd

Discussion Starter · #4 · Jun 29, 2011

Bob MacGregor
J-N decks one spring diameter space, RM decks on 3000-4000 series machines twice the spring diameter for the belt tension, check the adjustment with the deck lowered for mowing and running.

My guess was I had it too tight - it heated up and the rest is history.

99flhr
I then decrease tension until the belt strand coming off the spring loaded idler runs smoothly without undue movement or thrumming.

I like that idea - springs loose strength over time - not all are exactly equal. :thumbup:

As they say -- YMMV.

Thank you.

Bob MacGregor

· #5 · Jun 29, 2011

The spring would streach before the belt tension would ever get too tight. Something else is causing the belt to overheat and smoke up, probably the clutch.
That is the way that I adjust my belt tension, 448 and a 4018 over 1,000 hours on each with me mowing. I keep about 5 springs in stock and when the spring breaks mowing is all over until a new spring is installed and adjusted. The springs do break eventually no matter how they are adjusted. Vibration kills them in time. With a new belt the tension will change and need to be readjusted several times before the belt settles in.
Mad Mackie in CT

k0jdd

Discussion Starter · #6 · Jun 29, 2011

Well duh - here is another idea...

I looked at the old belt for wear and did not see any. I looked at the clutch. Looked at the mower deck for residue. Thats when I noticed signs of a little overflow from the hydraulic reservoir.

It was very hot today. Looks like she was too full and as the oil expanded it had no where to go but out and down. I have the level correct now.

Dang, its always the simple stuff... It sure wouldn't take much oil dripping on the belt/pulley to make her slip, now would it? Goodbye belt.

Thanks for the help Bob.

Hydriv

· #7 · Jun 29, 2011

It's funny that you concluded that was the problem. Over on MTF, there was a guy who was wondering WHY he couldn't fill his hydraulic reservoir right to the top.

You just found out why it's important to keep the level where the factory says it should be. :thumbsup: :thumbsup:

k0jdd

Discussion Starter · #8 · Jun 29, 2011

Now I just gotta remember to degrease the pulleys before I put on another belt!!! :lol: :lol: :lol:

A tip I would like to pass on. A turkey baster (bulb baster) is a great way to adjust the hydro oil level.
(At least I think so, but the Mrs. may have other thoughts if she catches me doing it.) :twisted:

The point where the bulb meets the tube gives you a depth gauge to work with.
When you can't suck any more out when inserting the tube to the correct depth, you're good to go. :thumbsup:

Hydriv

· #9 · Jun 29, 2011

Turkey basters can often be found at any Dollar Store and no tool box should be without one. They come in handy for a number of uses.

Bob MacGregor

· #10 · Jun 29, 2011

Don't let the turkeys find out that you are misusing their basters or they will have lobbyists, lawyers, the ACLU, the Justice Dept, the EPA and money from someones reelection fund and any others that they can muster up to bring to justice those who have misused a Chinese made turkey baster!!!! HaHa!!! :sidelaugh: :sidelaugh:
And yes I recall the MTF guy that wanted to fill the hydraulic reservoir to the top, not a good idea!! :thumbdown:
Mad Mackie in Taxonnecticut :twisted: :mrgreen: :mowlawn:

Reactions: 1

k0jdd

Discussion Starter · #11 · Jun 29, 2011

k0jdd said:
Now I just gotta remember to degrease the pulleys before I put on another belt!!! :lol: :lol: :lol: :

While degreasing the pulleys, I discovered a missing bolt between the idler bracket and the rear mounting frame. Another contributing factor! When it rains it pours. :letitsnow:

BTW - how freely should the pulley on a typical electric clutch rotate/spin when the clutch is not engaged?
Mine seems very tight, but I am not sure that it means anything. :headscratcher:

EDIT: I found my own answer: It should move 'stubbornly'. That's the result of the braking action required by OSHA to stop the attachment when the clutch is disengaged. :clap:

JD

Rockdog

· #12 · Jun 29, 2011

Does it have a brake on it?

tammy

· #13 · May 15, 2016

anyone help me? I have a huskee 46 inch cut model 13AB60647304490003 i put all new belts on now it wont stop i must turn key off to disengage. brakes are good but will not stop moving when engaged or gas let off
:sad:

jfk

· #14 · May 15, 2016 (Edited by Moderator)

tammy

Your mower is not a CCI, but it sounds like your electric clutch has locked up and will not disengage.
Could be an electrical issue, does clutch turn freely when not running?

Thanks
Jim

Bob MacGregor

· #15 · May 15, 2016

tammy, you need to get on lawnmowerforum.com to get suggestions that are more relative to your machine and it's problems.
This group here is very specialized to Colt, Case and Ingersoll garden tractors and related equipment. These machines are designed differently from usual and more popular lawn tractors.

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