m4900 PTO engagement troubles

[txranger]

Hi all, i'm new to the forums but have had the tractor a couple of years. This weekend, we finally broke down and bought a 6' bush hog from TSC. It is relatively light weight but I think it should be fine for our use, if i can get this problem figured out. Anyways, we got everythign hooked up and went to engage the PTO to start cutting, as soon as it engaged it broke the sheer pin on the bush hog. To say it nicely it engages ROUGHLY. Well we got a different bolt and used it, and it worked fine for approx an hour, and we never had troubles with it while the cutter was running and cutting. However, as i said it engaged really roughly and we ended up breaking 3 sheer pins over 2 days. The cutter runs fine, doesn't feel or look off balenced while it's running, the only time the pins would break is when first engaged. Is this a common thing with these PTO's? Or is the gear box on the cutter too light for the size of the tractor? We've run a post hole digger from TSC as well and have never had troubles with it. It's not a huge problem, more of a pain. Any tips or advice would be apprecitated...sorry for such a long winded post.....

 

[jcollins]

What is your engine RPM's when you engage the PTO? I would suggest engaging it at about 1500 rpms or what ever is the slowest speed that will keep the engine from stalling and then bring your engine up to the 2300 - 2400 rpms that is nessacary for 540 pto speed.

 

[txranger]

sorry, i thought i mentioned that....i dont know the exact RPM but it was at low idle, not revved up and the tractor wasn't in motion at all.

 

[equipman]

txranger
The M4900 has a hydraulic independent PTO and when the clutches do engage there is a jerk. Try and turn it on before you get into heavy grass to try and lighten the load on the blades. Hope this helps.
Lewis

 

[TBone]

I've had a M4900 for almost two years and have experienced much the same problem with a light bush hog (Bushhog Squealer). As Lewis said your tractor has a hydraulic independent pto that has absolutely no connection to your tractor's main clutch.

When you engage your pto you can lessen the jerk a little bit by sloooooowly moving the pto lever. Even then it is going to have a little jerk that is a pretty big shock to the shear bolts found on light duty bush hogs.

As Lewis also suggested you need to make sure you arn't in grass when you engage it. Just the weight of the stump jumper and the heavy blades are enough to put a strain on the shear bolts. Anything else that prevents them from turning easily will snap the bolts every time.

I finally solved my problem by getting rid of the Squealer and getting a heavier bush hog with a slip clutch. I really didn't fault the tractor for this problem. It was simply a mis-match with the light cutter. If you continue to have trouble and the light cutter meets your needs I would consider getting a slip clutch for it.

TBone

 

[txranger]

thanks for the replies, all. I will try and get a slip clutch for the cutter, i think it will meet our needs well since we wont be using it extensively or putting it to any kind of extreme use. Thanks again for the help!