[bcarlson]

Hi everyone I am fairly new to WFM and was hoping that someone could shed some light on a problem that I have with an electric pto clutch on a 1991 332. I bought this tractor over the summer in missouri as a spare/toy so I never mowed grass and used it to pull lawn sweepers and trailers. I absolutely love the tractor being a 318 fan for years. It sat indoors for many years and had low hours on it and this is the only problem I have had and I was wanting to install it on my model 49 snowthrower that I used on the 318. The clutch does not engage all the time and when it does it is not consistent I installed a new factory switch that i had as a spare and it might have helped a little bit but still the reaction time is delayed when it does work but if it sits for a while it goes back to same story and not come on at all any help would be greatly appreciated.

Thanks,

Brian Carlson

 

[woodpecker41]

Adjust the air gap on the clutch. I suspect it is to big or uneven. It should be about .015 to .018. Roger

 

[chuckv]

Brian,

Welcome to the WFM forum and to owning a 3 cylinder Yanmar engined tractor. I have two of the gas versions myself, 322 models.

Here is an excerpt from the TM1591 manual that shows how to adjust the PTO clutch/brake. The pictures show the 430 with the dual belt, but hte adjustment is the same... You might also want to measure the resistance of the PTO winding -- it should be in the range of 3.5 to 4.9 ohms. The sometimes develop internal shorts or intermittent failures in this winding, but most likely the issue is just an adjustment of the air gap.

Good luck and let us know what you find. Ideally you would have copies of both the TM1590 Service Manual for your 318 and the TM1591 for your 332 tractor. Each of these can be purchased on CD from your Deere dealer or from our site sponsor above, Keeping It Green. They run about $45 each...

Chuck

 

[bcarlson]

Thank you so much for your help Roger and Chuck I had heard of the air gap adjustments in the past but honestly have never had a problem with the clutches on any of the 300 series tractors so I have never even had one apart. Is it normal for one to change or are they that touchy? I am hoping it is an easy fix thank you guys for all off the useful information and I will keep you posted. Chuck this is my first diesel series tractor and I have had that blower on a 318 up until now and last night when the clutch finally would come on it just seemed like it snapped on harder than the 318 and I wasn't comfortable with the hard engagement on the blower itself and since i'm not familiar with the diesel 300 series i'm not sure if it is idling too high or if this is a characteristic of these tractors I greatly appreciate all your help once again thank you and I will post my results.

Thanks,

Brian Carlson

 

[chuckv]

Brian,

Every attachment manual that I have shows a recommendation to engage and disengage the PTO with the engine running at part throttle, this is to minimize wear and stress on the mechanisms. I don't have a snow blower (we don't have to shovel rain here in Oregon

) but the following is from my operator's manual for the tractor's mower deck, which is also driven by the same electric PTO.

As far as the PTO clutch/brake air gap is concerned, this assembly can wear over time, and occasionally the self locking nuts on the adjustments will fail to stay locked in place if they have been overheated and the nylon inserts damaged.

Here is a cross section view of the PTO assembly, note that the rim of the driven part with the belt pulley has a braking function when the PTO is disengaged -- this it to bring the attachment to a rapid stop once the switch is turned off. It is essential that the air gap is adjusted to the specified clearance of 0.018 +/- 0.003 so the brake does not drag (too little gap) or the PTO fails to engage (too large a gap...)

Chuck

 

[neil]

Chuck,
I thought it was so the engine didn't stall as the implement engaged - like giving the engine a bit of gas before letting out the clutch in a car. Does it actually say that it's to avoid wear and tear? (I might learn something new today...

Cheers,
Neil.

 

[chuckv]

Neil,

The discussion about engaging/disengaging the PTO only at part throttle always comes up when someone says the PTO makes a noise if engaged at WOT. Brian's comment about "hard engagement" was presumed to be at WOT, as that is the way many 318 users operate their machines if they have not done a close read of the manuals... Excessive wear on the metal PTO surfaces are thus avoided and undue stress on the rotational parts eliminated by following the manufacturer's recommendations as shown in the above illustrations excerpted from the factory published operator's literature.

Upon re-reading Brian's post I see where he was discussing IDLE speeds so I understand your comments. Your statement of why it is not done at slow idle is correct, don't want to stall the engine when it is at its slowest speed. It is much harder to stall a diesel of course...

Chuck

 

[bcarlson]

Well gentleman I adjusted the clutch per our discussion and the blower works like a charm even the idle engagement is to my satisfaction it sounds alot better when it engages not as harsh as before. The clutch air gap was very excessive so now I can finally put her to work no more idling around pulling a lawn sweeper thanks again for everyones help.

Thanks,

Brian Carlson