Z Force 48 Low Hour PTO Belt Breaks

[KJR]

I have a 2009 Cub Cadet Z Force 48 that likes to break PTO belts. The first occurance was at 17 hrs. I bought a new belt and had it mailed up to me (100 miles away from dealer). I took it to the dealer after I finished cutting my yard and they proceded to look at it and told me nothing was wrong. They were quite happy to charge me for 1/2 hr worth of labor because they couldn't find anything wrong, and warranty doesn't cover "nothing being wrong".

The second belt broke at about 35 hrs. While machine was running, I would look at it from the back and the belt seemed to have some harmonic vibration to it. It looked like it was moving so far in and out that it would polish up a spot on the shaft that runs your direction control going into the left hydro. The angle of the belt from the engine pulley to the deck pulley looked pretty steep too.

I took it in again to the dealer and it was the same song and dance. They checked engine speed and would set it to the mowing height and let it run outside their shop and run for long periods of time and could never find anything wrong.

The dealer told me that they heard from cub that I'm not supposed to engage my pto whith the deck lowered into the uncut grass. I don't have tall grass by any means. I live in town and keep it trimmed up. I can't imagine trying to cut grass for the first run of the season out at my parents farm with this thing. Maybe the belts would only last 10 hrs then.

The belt itself seems to run very hot as I have stopped cutting and shut everything down to grab it. It gets so hot that I can't even hold onto it. I don't think that should be normal should it?

This mower is really a nice mower except for this pto belt issue. It has 44 hrs on the clock now and I'm just waiting for the next one to go. If anyone has run across this or has any ideas please let me know.

Thanks

 

[rcbe]

KJR - the typical deck drive belt for CC machines is made of Kevlar. Effective belt length and correct cross-section dimensions are all critical. Make sure your belt is such, not a "will-fit" aftermarket item.
Also, check any idler pulleys involved for good condition; idler/tension pivots for free movement and correct tension springs and any belt guides for proper position

To help you to do such, find your machine's full model number and serial number off it's ID plate - go to this website to d/l a parts with diagrams for it:PDF Manual Web Archive

Certainly can't guarantee any of above will fix your problem, but may lead you to a problem cause. Good luck & post back with update/results.

 

[JTKub]

Is this the fabricated or stamped steel 48" deck?

There's no idlers on these, it's right from the PTO to the deck. You rely on the spring tensioner to pull on the deck drive pulley and the tension on the front U-hook to keep the PTO belt tight.

Do you need to snug up the front U-hook that attaches the front of the deck to the machine? On these ZTRs, tightening that will snug up the PTO belt (tightening it pulls the deck more forward and away from PTO). Too tight will give you problems too.

I never had any problems with my 2010 model year Z-Force 44 with the fab'd steel 44". The PTO belt was a REAL thick expensive looking sucker on that. I only had it for 1.5 seasons though and sold it along with the house.

Joel

 

[KJR]

KJR - the typical deck drive belt for CC machines is made of Kevlar. Effective belt length and correct cross-section dimensions are all critical. Make sure your belt is such, not a "will-fit" aftermarket item.
Also, check any idler pulleys involved for good condition; idler/tension pivots for free movement and correct tension springs and any belt guides for proper position

To help you to do such, find your machine's full model number and serial number off it's ID plate - go to this website to d/l a parts with diagrams for it:PDF Manual Web Archive

Certainly can't guarantee any of above will fix your problem, but may lead you to a problem cause. Good luck & post back with update/results.

My machine's PTO belt has always been replaced with genuine Cub Cadet Belts. The tensioner arm moves freely and is well lubricated, as are the idlers on the arm. Thanks for the link for the parts manual. That will come in handy if I need to order parts over the phone.

 

[KJR]

Is this the fabricated or stamped steel 48" deck?

There's no idlers on these, it's right from the PTO to the deck. You rely on the spring tensioner to pull on the deck drive pulley and the tension on the front U-hook to keep the PTO belt tight.

Do you need to snug up the front U-hook that attaches the front of the deck to the machine? On these ZTRs, tightening that will snug up the PTO belt (tightening it pulls the deck more forward and away from PTO). Too tight will give you problems too.

I never had any problems with my 2010 model year Z-Force 44 with the fab'd steel 44". The PTO belt was a REAL thick expensive looking sucker on that. I only had it for 1.5 seasons though and sold it along with the house.

Joel

Joel,
My machine has got a fabricated deck on it. The PTO belt has a spring loaded tensioner arm with two idlers on it. One is V shaped for the belt to run in and the other is flat for the back of the belt to run on. I'm not sure if there is a procedure to check the tension and adjust it with the U hook. I guess I just took for granted that the mechanics that looked at my machine would have done that. I'll have to check my manual for sure. My machine also has a big thick expensive kevlar belt that looks like it should last 10 years, but the first two sure didn't. Maybe third time is the charm. I also raised the height setting where I cut my lawn at in hopes of achieving a better angle on the pulleys.

 

[GBHRPS]

KJR,

I had a similar problem with my used 2008 Z Force 48. It destroyed the belt it was delivered with the second time I used the unit. The next new belt would be chewed up and spit off its pulleys about every twenty minutes of use.

I finally got fed up with the issue, after measuring and checking every angle of all the pulleys, checking every bearing, and still saw the belt wobbling and fluctuating while in use.

What I did was get a new kevlar belt (as were the other two) and kept the chewed up 2nd one as a spare. I installed the belt permanently on the deck itself. On each of the deck's two PTO pulleys, I installed an ordinary bolt that would prevent the belt from coming off the pulley.

On the spring tensioner arm (of my unit) there was a hole in the tensioner assembly arm right next to the pulley's outboard edge, where a short bolt rising up from the arm would prevent the belt from coming off (about 1/4 inch clearance between the bolt and the edge of the belt).

Likewise on the deck I drilled a hole through the deck and put a longer bolt that reached up to a like position next to the fixed pulley.

This system has worked flawlessly for the last 80 hours with no belt damage or any more tossed belts. The only down side, is that when the deck is installed back on the tractor, the PTO belt has to be slipped onto the PTO itself before tightening the tensioner bar. Not a big deal.

If this explanation doesn't quite do it for you, I could take some pictures and post them in a day or two. Good Luck!

 

[JTKub]

My machine has got a fabricated deck on it. The PTO belt has a spring loaded tensioner arm with two idlers on it. One is V shaped for the belt to run in and the other is flat for the back of the belt to run on.

I'm mixing up my 2544 with my Z-Force!

Not the best pic, but mine had a spring loaded tensioner system on the deck itself. You can just make out the flat and V-pulley. Red globs of gooey goodness grease compliments of dealer setup:

Joel

 

[savageactor7]

Well that was a clever fix GBHRPS.

 

[Alien]

I have a Husqvarna and the belt broke in the first week. I have had a lot to do with belts over the years (even had a few when I was a kid) so when I looked at the broken belt I could see it was faulty. The Husqvarna dealer would not replace it so I got a bit pooey about it. He wouldn't budge but then decided to give me one at trade price. How sweet of him. I know that one factory was having problems with belts back then and I am sure I got one of their duds. The replacement belt is still going after 8 years of very tough work and still looks fine. However, I have a long memeory and that dealer will get no more sales to me. I am just pissed because I had spent so much money there with chainsaws and mowers etc etc.