PTO clutch Nuffield 460

A place for general Nuffield questions and chat
chris4560
Posts: 11
Joined: Sun Jul 14, 2019 6:18 am
Australia

PTO clutch Nuffield 460

Post by chris4560 » Sun Jul 14, 2019 12:17 pm

hi All,

my first post here! i have read quite a few topics here today and have learned a huge amount already!

so much information here, and all shared so generously.

i live on the sunshine coast in south east Queensland, Australia

I have a Nuffield 460 i bought about 9 years ago as a bit of a project- sadly i let it sit for all of that- but under shelter.

this weekend i got the old girl running- it took awhile but she now starts easily.

i have a few questions, and i am looking for help with the PTO

1. the select lever on the left hand side of the PTO- it moves freely- in the most forward position the hydraulics do not lift and the PTO does not spin so i assume this is the disengaged position. the lever moves quite easily to the middle position, but it does not engage anything- arms do not lift and PTO does not spin and no sound of a pump working.

I can move the select lever back further- but not all the way- it then starts a gearing meshing sort of noise but will not move all the way up.

I have tried using the foot clutch to help engage the PTO- no joy - the clutch works fine for the transmission gears.

My 460 has the hand clutch lever to the on the left side- it is all connected, but moves VERY freely- it does not help with getting the hydro gear to engage into the rear most position. (when i am doing all of the above the engine is running and transmission is in neutral)

when i turn the tractor off i can sometimes force the hydro select lever into the rear most position- i then start the tractor.

half the time the hydro gear select gets kicked out of the rearward position and goes close to the middle position- the hydro pump runs, and the lift arm lever works and raises and lowers the arms. the PTO also spins, but i can stop the PTO spinning by grabbing it with my hand. ( i assume PTO is only partially engaged?)

the other half of the time the hydro select will stay in the most rearward position- the hydro pump runs, and the lift arm lever works and raises and lowers the arms. the PTO also spins, but i can stop the PTO spinning by grabbing it with my hand. ( i assume PTO is still only partially engaged?)

( i have stopped and started the tractor about a dozen times)

on only one occasion the PTO was spinning and i could NOT stop it by hand- so i assumed the hydro select lever had actually fully engaged the PTO?


transmission Oil level is full- i did drain a bit of oil out of both drain plugs under the rear of the tractor- there seemed to be a bit oif water that came out first (maybe only 50mL?) and then some very brown oil.

I prob only took about 5 Litres out, and topped it up again with some 10/40 oil so it is back to being full (as per the dipstick near the gear lever).


i took the PTO select lever off- put a spanner on the shaft but couldn't get it to turn ( i gave a fair bit of effort but not too much as i did not want to break anything). The PTO select lever square hole looks a bit worn, but when i put it back on and tighten its nut and spring washer it will move the shaft.

can anybody shine any light on what my PTO, PTO lever, and PTO clutch might be doing?



diggerdeano
Senior Member
Posts: 387
Joined: Sat Mar 31, 2018 9:04 am
Great Britain

Re: PTO clutch Nuffield 460

Post by diggerdeano » Sun Jul 14, 2019 9:24 pm

dont get hold of a pto shaft my cousin did this in canada and i ended up taking him to emergency room to get him fixed it almost tore his thumb off broke his wrist and he has limited movement in his hand now .does your pto hand clutch feel like its moving anything you say it moves freely and there should be some resistance when you pull it back to disengage drive

chris4560
Posts: 11
Joined: Sun Jul 14, 2019 6:18 am
Australia

Re: PTO clutch Nuffield 460

Post by chris4560 » Sun Jul 14, 2019 9:49 pm

hi Digger, thank you for the reply.

Yes i am very careful with the PTO shaft- engine on idle and i use an open hand- thanks for the advice.

re the hand clutch- no resistance at all in either direction, with the hydro lever in any position.

the hand clutch linkages all look intact, and i see it rotating the small shaft that goes into the clutch area.

i assume something is stuck or an internal linkage is undone?

JohnM
Posts: 10
Joined: Sun Jul 07, 2019 9:46 am
Great Britain

Re: PTO clutch Nuffield 460

Post by JohnM » Sun Jul 14, 2019 9:51 pm

Sounds like you have a couple of problems, the main one being that the hand pto clutch lever is not disengaging the pto clutch. Also if square in the lever is worn it is not fully engaging the gear, hence the jumping out.
You are right about what the lever does, forward is not engaged, middle position is the pump and rear position is pump plus pto. Presumably the only reason you cant get it to engage with the tractor stopped is that the cogs are not lined up. When working properly you often have to release the hand clutch lever then try again to engage the gear.
With your worn lever you are probably not engaging the pump in the middle position and only just in the far position but the main issue is why the pto clutch is not disengaging when you operate the hand lever. Hopefully it could just be stuck on the flywheel or the splines are rusty after standing so long. Obviously the foot clutch is OK but this has nothing to do with the pto.

chris4560
Posts: 11
Joined: Sun Jul 14, 2019 6:18 am
Australia

Re: PTO clutch Nuffield 460

Post by chris4560 » Sun Jul 14, 2019 10:06 pm

thanks John,

i will sort the lever square hole with a bit of flat plate.

re the PTO clutch- is getting to that a big job? is there an access plate somewhere?

as a kid my dad had a David Brown 990- the foot clutch for the gears was also the PTO clutch- you just had to push it all the way down ( i remember it was a struggle when i was short ). i wasn't sure whether the Nuffield has the same set up so i was trying everything i could.

any help is greatly appreciated!

thank you all again.

Chris

JohnM
Posts: 10
Joined: Sun Jul 07, 2019 9:46 am
Great Britain

Re: PTO clutch Nuffield 460

Post by JohnM » Sun Jul 14, 2019 10:13 pm

I have put a clutch (or clutches) in a 10/60 but it was many years ago so have forgot how I did it although I am sure someone on here will explain all.
From memory, which isn't very good, there is an inspection plate (at least on a 10/60) and the clutch can be changed without splitting the tractor. I think it needs tank off then the top of the bell housing lifts off which may well reveal your issue.
Best of luck.

chris4560
Posts: 11
Joined: Sun Jul 14, 2019 6:18 am
Australia

Re: PTO clutch Nuffield 460

Post by chris4560 » Sun Jul 14, 2019 10:17 pm

thanks very much John.


cheers

mike.l
Posts: 99
Joined: Fri Mar 30, 2018 10:29 pm
Canada

Re: PTO clutch Nuffield 460

Post by mike.l » Mon Jul 15, 2019 1:29 am

Hi before you start to rip the tank and other parts off there is a sq inspection plate on the side just in front of the hand clutch leaver look in side. to see if the hand clutch leaver is moving anything. You should be able to adjust the free play on the hand clutch so that the leaver starts to get pressure as soon as it has traveled 1" measured at the end of the hand leaver it is in the inspection hole that you can dump a small amount of penetrating oil on the forks and splines . just see what moves in there then we can help you more Take the gate off so you can move the leaver further in the second and third positions .( On one of my tractors i put 1" spacers to move the gate further back) This is what i would do to the tractor if it was in my care mike

chris4560
Posts: 11
Joined: Sun Jul 14, 2019 6:18 am
Australia

Re: PTO clutch Nuffield 460

Post by chris4560 » Mon Jul 15, 2019 3:17 am

Excellent!

Thanks Mike I will do that.

I will report back in the next few days on how I go.

Many times thanks to all who have provided advice.

Cheers,

Chris

chris4560
Posts: 11
Joined: Sun Jul 14, 2019 6:18 am
Australia

Re: PTO clutch Nuffield 460

Post by chris4560 » Tue Jul 16, 2019 8:45 am

hey Mike,

I took the square cover plate off in front of the PTO clutch.

Everything appears to be moving quite freely.

i am uploading videos to youtube that i will link to here.

i am hoping that these videos will help- i have one where the engine is switched off, but i move the clutch forward and back, and then a video with the engine running, as i move the clutch forward and back.

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