4630 independent PTO noise

[Patf10]

Well I am having a problem with the ipto on my 4630. When i start the pto I can hear a noise like gears grinding for a second then it goes away. Also when brush hogging if I hit something i can hear the same noise. I'm assuming the splines on the clutches for the pto have probably stripped. From what i have searched I will have to split the tractor to fix this, but I figured id see if anyone had any more insight as to what all I may have broken inside.

Thanks
Pat

 

[TractorTech]

Pat, not likely that the splines have stripped or it wouldn't get the brush cutter spinning. Is the 4630 4wd? Is the sound coming from directly under seat or from the rear around the PTO output shaft?

 

[Patf10]

It is a 4wd 8x8 syncro transmission. The noise comes out under the seat/ in the rear end somewhere. Like i said it does it shortly if you engage the PTO and then it will do it if the brush hog hits something big.

 

[jimmysisson]

Is there a slip clutch in the brush hog pto shaft? Chattering?
Jim

 

[Patf10]

There is a slip clutch but it is not coming from that. It sounds like a fine tooth gear slipping/ grinding. Ive had slip clutches slip and the noise is nothing like this.

 

[Patf10]

Ok so more investigation last night. Put on our small 5ft brush hog and tried to get the noise to occur on start up like we do on the 8ft cutter. No luck there which is good. We loosened the slip clutch and still nothing. Now we put the brush hog into some small stumps and you can surely hear the slip clutch chatter and it travels into the tractor.

I was going to replace the discs on the 8ft cutter slip clutch and see if the clutch is slipping on start up. I find it hard to believe that it is slipping on startup, but that cutter does take a decent bit to get moving.

 

[Patf10]

Well more investigation, its something PTO the slip clutch isnt slipping on startup but its making a grinding noise in the tractor.

 

[pmsmechanic]

My guess is that it's either the splines gone as already mentioned or the clutch plates are worn and they are chattering when they slip. If it was the spines and you have still been using the PTO I'm thinking then there wouldn't be any power transferred to the PTO shaft by now. So my guess is that the clutch plates are worn and there is chattering when they slip.

 

[Patf10]

That sounds feasible, it makes a little noise on a soft start up but then once you are mowing it doesnt make any more noise.

 

[TractorTech]

If you want to get a look at the PTO 4WD geartrain without too much disassembly, drain the rearend oil and drop the 4WD dropbox. I am thinking you may have a bearing problem or interference problem between the 4WD idler and PTO clutch. This was a problem with the D series tractor loaders and was reworked to separate the idler from the PTO clutch. I don't see that in the 4630.
At the very least drain some or all of your rearend oil and check for metal filings.
I don't mean to be an alarmist, but a little inspection can save a lot of money as many of these parts are getting hard to get.