Brand new mower deck belt keeps jumping off

[jpilk99]

Well, one more idea has failed. I had put an additional washer #97 in the tensioner idler arm pulley as I thought the idler pulley #52 had too much up 'n down movement, and since my belt seems to only jump when the deck is low (other than the highest, 7th position)... I thought this would help. Since this was not in Husqy's build, I took it out. Went back and quadruple checked my heights and, although close, the rear blade tip measurement is within the 1/8" to 1/2" range. Felt like I was chasing my tail as lowering the rear or raising the front didn't make much difference... I'm wondering if I'm closer to the 1/2" difference in heights, that maybe that's my problem, I should be, say, 1/4". But again, I couldn't seem to get to that.

Again, everything used to work fine, but, something is clearly not right and I'm not finding it. Only other thing I wonder is if the tensioner spring is not strong enough any more. In some of the videos I took and posted here, I thought - after the PTO was engaged, the "flop" in the belt was more than it should be. It's basically a new belt, less than a couple hours on it.

Maybe I'll buy another spring and just try it, but, I'm kinda loathe to just buying replacement parts of a 'system' hoping it will make the difference. I'm trying to understand WHY this is actually going on.

Thanks for any help.

Jay

 

[Deere Dude]

In the video it seems the belt is bouncing around quite a bit and from reading a few older posts that should be a new belt. What if the new belt is not up to snuff. I would try the old drive belt on it again. Unless you did it already.
I can't imagine the frustration you are having right now with that thing. Good luck.

 

[jpilk99]

In the video it seems the belt is bouncing around quite a bit and from reading a few older posts that should be a new belt. What if the new belt is not up to snuff. I would try the old drive belt on it again. Unless you did it already.
I can't imagine the frustration you are having right now with that thing. Good luck.

Thanks Deere Dude. It's possible (I gather) that with the number of times this belt has jumped, that that in and of itself would cause it to stretch. I'll order a new belt; OEM.

The one thing (of many I guess) I'm stuck on right now is: I don't read anywhere that says the Link Lift Susp Mower Rear should support the mower deck at X/xx inches above flat ground when in ABC position (highest or lowest). Then I would know when end I should be chasing when it comes to trying to make sure the front of the blades (when pointing forward) is between 1/8" to 1/2" lower than the rear.

 

[3Ts]

Have you checked to be sure all the pulleys (and idlers) are in the same plane?

 

[jpilk99]

Have you checked to be sure all the pulleys (and idlers) are in the same plane?

Yes, and they are. (Good question).

I'm looking at new belts and seeing a slight difference in some, even when I search for OEM: 5/8 and 147.5 up to 11/16 and 148.25. I'm thinking, get the smallest length possible, hence tighter... I don't know what Husqy had on this Day 1.

 

[3Ts]

I'm looking at new belts and seeing a slight difference in some, even when I search for OEM: 5/8 and 147.5 up to 11/16 and 148.25. I'm thinking, get the smallest length possible, hence tighter... I don't know what Husqy had on this Day 1.

I'm sure you're aware there are different cross sections of belts and they fit the pulleys differently. For example there are "A" belts and "B" belts and a whole bunch of others. The wrong cross section may be contributing as well. The "standard" v-belt has a different angle than the narrow belts and will fit the pulleys differently.

Guide to V-Belt Selection and Replacement | PTE

 

[jpilk99]

I'm sure you're aware there are different cross sections of belts and they fit the pulleys differently. For example there are "A" belts and "B" belts and a whole bunch of others. The wrong cross section may be contributing as well. The "standard" v-belt has a different angle than the narrow belts and will fit the pulleys differently.

Guide to V-Belt Selection and Replacement | PTE

Hi 3Ts. Sadly, I've never heard of the "different cross sections of belts and they fit pulleys differently". I can certainly understand, given the slight variation in dimensions listed on the web. I know nothing of cross sections either. I just searched on the part number and "OEM"... After looking at the link you provided, I still don't know if I should buy a different belt than the "OEM" one I just purchased.

Thanks regardless.

Jay

 

[jpilk99]

ALL:

Thank you for your help on this. I believe the issues is resolved and that was by lowering the rear of the mower deck. I also got a new belt (again) as well as a new tension-arm spring. It still looks like there's a healthy amount of "flop" in the belt as I'm able to look down through the slot to my left where the deck raise/lower handle & slots are and I can see the belt in motion. Not sure what I can do about it as I have the new OEM spring putting tension on the idler pulley.

Thank you again all!!!! SOOOO nice to mow my lawn again.

Jay

 

[NotLawn]

Noob here, but... If it jumps off when set low, then maybe belt tension is too high? Because the tension increases as you lower it. Or adjust the belt tension while it is set to the second lowest setting, which is the one that gives you trouble. You said that the tension looks loose in the video. I used to tighten my belt too much and had lots of trouble. Also, the new kevlar belts are a nightmare. Use one of the lower tech ones.

 

[Richard001]

Noob here, but... If it jumps off when set low, then maybe belt tension is too high? Because the tension increases as you lower it. Or adjust the belt tension while it is set to the second lowest setting, which is the one that gives you trouble. You said that the tension looks loose in the video. I used to tighten my belt too much and had lots of trouble. Also, the new kevlar belts are a nightmare. Use one of the lower tech ones.

NotL, Welcome to TBN.

I doubt that a belt will jump off if it is too tight. Most problems with the belt jumping off is from either poor pulley alignment or the belt is flopping around and jumps off.

In the past, I have used a rubber snubber to limit the movement of the tensioner pulley.

Richard