MF 165 Independent PTO - strange symptoms

Hi all,

I have a 1968 MF 165 Diesel with an independent PTO (no multipower, so just a small auxiliary hydraulic pump for the clutch pack.) Had the PTO clutch pack go bad on me last year (of course right in the middle of first cut), and a local dealer fixed it for me with refurbished parts (new was quoted at a $10,000 repair bill - got it down to $3,200 with used/refurbished - still hurt.) This job replaced the clutch pack and aux hydraulic pump, and sent out the main hydraulic pump to have the PTO bushing (which had disappeared) re-installed. The mechanic also said he machined some burrs out of the PTO shaft where it goes through the main pump.

The PTO has worked for the past 9 months since I got the tractor back. However, there are a few strange things that are causing me to hold my breath about it:

1) When engaging the PTO under load (mainly the baler), I get a short hydraulic grunt/squeak from under the seat (where all the magic happens) about 75% of the time. This didn't happen before. Happens at all rpm's, though I always try to do it at an idle just to minimize shock.

2) *Only* with the new (to me) tedder I purchased (a 4-head Vicon RS410T), when turning corners with the PTO engaged I get a strange clicking/crunching sound under the seat, again where all the magic happens. Sort of rhythmic, but in short bursts. No loss of PTO power or anything other than the sound, but certainly doesn't sound right. I worry it's some kind of side-to-side slop where the shaft was machined and it goes through the main pump, but I'm just talking out of my butt about that. And no sign of that sound running any other piece of equipment, or when driving straight with the tedder.

3) Toward the end of last fall, I started the tractor a couple of times to find that the PTO would turn on with it (attached to a brush hog), even though the lever was in the off position. A similar thing has happened this spring with the fertilizer spreader. It seems to happen more when the tractor is cold, and I have yet to have it happen when hooked to an implement under higher load (like the mower or baler), but then again haven't used them much since last fall. Unsure if this is a related to the above, or if it's a matter of the PTO lever being worn / not quite disengaging fully. (Roll pin doesn't look too worn, but there is a little bit of slop. Not sure if there is any adjustment to be made there.)

Phew, sorry for the novel. Anyone have any experience with any of the above, or thoughts on whether I ought to be prepared for it to give out any given day? I'm afraid if the PTO gives out that's curtains for this tractor - love it, but can't afford to be sinking several grand into it every year. But would also like to sleep better at night if folks think this isn't another catastrophic failure waiting to happen.

Thanks!!

I have a video on you tube of the strange crunching/clicking sound while turning with the tedder, but for some reason the forum won't let me post it or a url here.

If you go to you tube and search "MF 165 strange PTO sound" it'll come up.

Thanks!

The PTO brake on those for the drum was not very heavy, and if the main plates start to warp the brake in most cases will no longer hold. What usually kills the hydraulic PTO and/or Multi-Power clutch packs on those tractors is running too low on hydraulic oil. Slightly over full won't hurt anything. Dad's 180 years ago had burned/warped PTO plates for two years before it was repaired, it would not start a heavy load, but would never slip if it did get started. During that time the PTO brake would not stop it at all. Never heard any noises on it though..

A ipto killer is engaging it while the implement has some kind of excessive load on it, and or engaging it while the engine rpm is high, the ipto clutch pack doesn't like that. Disengaging the ipto while the implement is still turning at a fast speed kills the little brake that the ipto has. The ipto brake is only for keeping the pto shaft from turning when the pto is not engaged, its not for stopping a implement running at speed. Idle the engine before engaging with no load on it (besides the load the implement puts on it), and idle the engine down to slow the implement down first before disengaging the pto. I'm not saying you are doing those things, I'm just saying what hurts it the most, and the fastest.

That makes a lot of sense with the PTO brake - I?m
always careful to only engage the PTO at an idle
(and even so I get the grunt/squeak with the baler
and mower) but I?ll admit I often disengage at or
around 540. I?ll stop that habit right now. (I really
wish they wouldn?t have put a brake on it - I find
myself much preferring the two stage live PTO on
my MF 135 - I can deal with having to use my foot,
especially if with the iPTO you need to idle before
starting / stopping...what?s the point of having it?)

Whining aside, how do you think the PTO brake fits
in with the three symptoms I described? And, If the
brake goes bad, how does that affect the clutch
pack and/or auxiliary pump?

Thanks!!

Thanks, that?s very helpful. Given that the pack was replaced last summer, I sure hope they aren?t warping again. Is the brake part of the clutch pack, I.e. would it be replaced along with the pack? If not I imagine it?s still running with the old brake, which judging by your description wouldn?t be too happy.

Still feeling unclear about whether a bad brake can ruin a clutch pack, or just the other way around. I can deal with a bad brake, just not a bad PTO. Guessing this fits in with my ?PTO turning when I turn on the tractor? problem, i.e. the brake isn?t holding. In this case is the PTO under full power, or just lightly turning due to poor braking (but would stop under a higher load)?

Loud and clear on the hydraulic fluid levels. I?ll be extra sure it?s topped off (and then some.)

Thanks again!

Easiest way to check for warped PTO clutch plates, with the tractor OFF try turning the PTO shaft by hand. It SHOULD turn with little drag. If you need a bar through the hole, or a wrench to turn it, disc plates are warped. While it is designed to start heavy loads, try to avoid doing it. The MP clutch has three discs, and works fine shifting in or out under load. The PTO has six or seven discs, similar to the MF 1100 series clutch that I've seen hold 200 plus horse power. For better MP clutch life, I've used the PTO discs from the 1100 as the friction material is different, but the released clearance needs to be checked..

The brake on the ipto is usually a brake band around the clutch drum, or a little disk brake which can usually be repaired without going into the clutch pack. All having a worn pto brake will do it let the pto shaft turn some while the pto is not engaged while the engine is running. But be very careful if you are around anything pto driven when its hooked up while the engine is running with the pto disengaged. I would also do the test as Dieseltech suggested to check the pto clutch plates.

Thanks all, this is making me feel a lot better.

I know the PTO turns by hand when the tractor is off
and it?s disengaged, so it sounds like my clutch
pack is ok. I used to work at a university farm that
had a 175 with an iPTO and it would routinely have
the PTO turning even when disengaged, but it
would stop if it encountered too much resistance.
So, sounds like it?s something to keep my eye on,
and to be extra careful about while the tractor is
running.

Still scratching my head about the hydraulic
squeak/grunt when engaging - do you all think that?s
related to the brake as well? (ie the brake is trying
to hold at first?)

Thanks!

This is a photo of my 150. Just posted FYI. I can't help with the noise.

I don't know if it helps any, but I use an over-running clutch on the PTO shaft when running my Brush Cutter.

You know, I?ve been wondering about the overrunning PTO idea - I think I might try it, st least with a brush hog. Tempted to try that with my hay mower too, but I worry about some unintended consequence with something like the hay mower, especially if my PTO does have some internal slop or vibrations.

Thanks!