B7610 Newb Question

jeffgbook · Mar 4, 2005

I used my RMM mower on my B7610 for the first time today, and I stop regularly to put it in 4WD or to take it out of 4WD. With the PTO on 540 when I press the clutch in it makes a knocking sound.

It has something to do with the PTO, because it (the noise) gradually slows and stops with the PTO. It almost sounds like a stick or something is caught up in the mid-PTO, because the noise is not coming from the rear. Sounds like it's right under the engine.

Anybody had this happen to them (B7610 or not)? It seems to do it when the mower has been running for a few minutes. Thanks. Jeff

Henro · Mar 4, 2005

jeffgbook,

First thing that came to mind is the mid PTO should not be engaged when you are using the rear PTO for the RFM.

Sounds don't always come from where they sound like they are...but IF you are pretty sure that sound is internal, if the tractor is still under warranty, you might want the dealer to check it out. Do you have anything else you can put on the rear PTO and see if the sound is still there with the RFM off?

I don't have a B7610, but I THINK my B2910 is similar in the way the PTOs operate...I never noticed anything like you are describing when using a RFM, or rotary cutter on the back of mine...I would be concerned.

Maybe someone else can be of more help. I hope so... /forums/images/graemlins/blush.gif

BOTAMAN · Mar 4, 2005

The noise you are hearing is the overrunning clutch on the pto whenever you clutch the tractor the pto clutch is ratcheting inside so the momentum of the blades does not try to push the tractor. It works on the same principle as the clutches we used to put on the old 8n's to keep them from pushing the tractor when you were using a pto implement & clutched the tractor.

Henro · Mar 4, 2005

The noise you are hearing is the overrunning clutch on the pto whenever you clutch the tractor the pto clutch is ratcheting inside so the momentum of the blades does not try to push the tractor 

Botaman,

Are you sure about that?

I don't know, but I am pretty sure that my B2910, which is a HST transmission, does not have an overrunning clutch. When I cut the engine speed back, the engine slows the rotary cutter (at least as far as I can remember). Actually, I am about 99 percent sure when I cut the engine speed back, the cutter shows due to engine braking.

Then once the clutch is depressed and the PTO disengaged, the cutter then takes a while to stop.

I would expect, but don't know, that the B7610 would work about the same way...

Unless you meant the tractor in question has an over running clutch on the PTO drive line, external to the tractor...I don't remember reading that in the original post...have to go back and reread after posting this...Never gave that a thought, as with a HST the PTO does not drive the tractor when the HST pedal is centered...so the need for an over running clutch is not there.

jeffgbook · Mar 4, 2005

Hi fellas. Thanks for the responses.

I did fail to mention that it was HST. I don't know if that rules out BOTAMAN's theory or not (i'm tractor dumb), but "ratcheting" is the perfect word for the sound.

Henro, I do have a cutter that I will hook up tomorrow to see if it does the same thing.

Thanks again fellas, and if anything else comes to mind please share it. Jeff.

MoBota · Mar 4, 2005

( First thing that came to mind is the mid PTO should not be engaged when you are using the rear PTO for the RFM. )

I know what your sayin' Henro but on this economy type tractor we have just the single pto lever and the mid always turns at either 950 ( while the rear is 540) or 2550 RPM and the rear is still, memory serving.

Haven't mowed with mine but I do use the clutch to engage the pto for the backhoe, haven't noticed any ratcheting sounds so far. Of course the BH pump has no momentum compared to a RMM. Let us know what you turn up and good luck.

Mo

Suess · Mar 5, 2005

Our B7610 pto does not free wheel it does make a clicking sound when disengaged and left to free wheel to a stop. Our front pto does not turn in the 540 speed. I do use the 960 rear speed for the wood chipper and the front pto spins then. No noise when you slow the engine down I don't remember any clicking when I just push in the clutch. The only time is if the pto leaver is put in nutral with the machene spinning.

BOTAMAN · Mar 5, 2005

I checked to make sure what I said was correct. Your 2910 does not use the one way clucth as it is called in the service manual. It is used on the 7510 & 7610, on these models you will not hear any noise if you reduce engine rpm's, I beleive you will only here a noise when the clutch is depressed. If you stop the engine without turning off the pto you may here the noise then as well. Acording to the service manual the rear pto also has a one way clutch.
My B8200 is a older model, but it has a clutch in it , sometimes I will stop the engine before the blades stop turning & I get the same noise.

jeffgbook · Mar 5, 2005

So this is normal?

I just want to make sure something's not wrong before I use it again. I'm going to hook up to the cutter today to see if it makes the same noise.

I've used the cutter before and it didn't, but I'm going to try it anyway. Thanks. Jeff

BOTAMAN · Mar 5, 2005

If the only time you are hearing the noise is when your are turning off the mower it's normal, if you are hearing the noise while operating the mower you need to have it checked out.