New Holland 411 disk mower conditioner problem

[David333]

I have a problem with a New Holland 411 disk mower conditioner, and I need some help.

The problem is with the conditioner roller drive shafts - the universal joint yokes are constantly breaking. The top roller yoke has broken once and the bottom one has broken twice.
I have tried relieving the tension on the rollers but this does not seem to make any difference.
Everything turns freely by hand and seems to be OK, but the darn things keep breaking.
I also have a problem which may be related but I am not sure, when I turn to the right while cutting, the drive train makes a loud kinda like a clanking noise. This may be when the yolks break but I am not certain. When going straight or turning left it does not make the noise.
I have checked the drive train for loose / worn parts and everything seems to be tight.
I only operate the unit when it is fully open and I engage the P.T.O. at a low R.P.M. and then bring it up to operating speed. (540 R.P.M.)

I would appreciate any suggestions anyone may have concerning this problem and I thank you in advance.

 

[Shetland Sheepdog]

I have a NH408 which should be the same machine (just 5 discs instead of 6).
Have you checked your roll timing? Raised portion of one roll should mesh '"dead center" of recessed portion of opposite roll!
Check your operators manual for timing proceedure.
If you don't have a manual, post back and I'll try to give you more info.
Dave

 

[RodinNS]

Dunno... but I'd be looking at the roll timing and the bearings on the rollers.

Rod

 

[RickB]

Check the roll gap. Roll gap and roll tension are two different adjustments. Also the roll timing, as mentioned. As for the chatter on RH turns, do you have a drawbar extension on your tractor?

 

[lfc]

On the clattering during cornering, check the plastic liners that the pto shafts telescope within, especially on the long shaft from the PTO gearbox to the head. The shaft may not feel like it wobbles much, but new liners will make a big difference. They aren't cheap - something like $50 a set. I think I've replaced them twice on our 411. You might also want to check the bushing on the over running clutch.

 

[David333]

Thanks Guys for the info, I believe I have discovered part of the problem, although now I have to figure out how to fix it. The rollers are vertically out of line, the bottom roller is centered about 3/4 - 1 to the right of the top roller, this causes the right half to rub on the top corners of the top roller. The problem cannot be adjusted out-- one side hits or the other side hits, I need to center the rollers. Any one know how to do this ? The rollers were changed before I bought it by the dealer, so I guess they screwed up.

In response to:

RickB, yes I have a draw bar extension and it complies with the specs on the NH411.

lfc, I have changed the liners on the long shaft (there were none at all) and the noise has lessened but still persists. The slip clutch does seem to have a bit of play in it and I will check it more thoroughly as time permits.

RodInNS, Bearings seem OK, timing is screwed because of off center rollers.

Shetland Sheepdog, I just picked up a manual but unfortunately it does not tell me how to center the rollers.

Thanks.

David333

 

[Shetland Sheepdog]

David, I can't help you on the endways adjustment! I was referring to the adjustment for timing the rotation at the roll drive universals. Your manual probably describes that.
Sorry 'bout that! Dave

 

[Tx Jim]

David333
Presuming it has locking collars on crimper brgs,loosen the LC's on brgs and move roller to line it to other one.