35 Clutch Drag

Picked up a SNMY (1963 build) today.
My question is about clutch drag and pressure required to operate the clutch.
Find it best to change gears with engine at idle or clutch drag can be a problem. Also find pressure to disengage the first stage very high when compared the clutch on old 80mm bore TEA20.
Will a clutch rebuild make disengagement pressure light or is this typical of the two stage clutch.
The little Perkins runs sweat but will take some getting used to.
Assume the Y of SNMY is for the diff lock (bit flash as I have never had a Fergie with a diff lock) is this correct?
Thats the old TEA 20 hiding around the corner (will be hanging on to her)

You have arguably bought one of the finest Massey Ferguson tractors ever built. If only you could still buy quality like this now, simple, reliable, tough and user friendly!
The dual stage clutch in this tractor is very much a different clutch to your faithful TE 20 tractor.
These are a "beefier" clutch than the 20"s.
You will definitely "feel" the extra spring pressure, especially when pushing the pedal thru the "second", or PTO stage. This is normal.
The dual clutch fitted to these tractors will indeed, not disengage as quickly in the drive from either the main or the PTO transmission drive-trains, as your TE 20 does in retrospect. Inertia within the transmission has a lot to do with this.
It will be a matter of getting used to a longer "lag" from depressing the pedal, to engaging the main gearstick or PTO shift mechanism.
If you are experiencing quite a deal of "grating" when selecting a drive gear, it is possible to reduce this, by placing the HI-LOW lever in neutral, selecting the required "speed" gear first, then selecting "low" in the range change. This has the effect of "slowing" the transmission gear inertia. Then shift to high afterwards, if this is the range speed that you require. Later model Massey tractors with the larger 12" dual clutches suffered somewhat, with this same phenomenon. A service bulletin was issued soon after, detailing the same shifting procedure as I have previously mentioned.
The last of the MF 35's had diff lock as an option. The 35x's had a larger horsepower rating than the standard 3 cylinder 35's, and, again were available with the diff lock as a option, (not standard).
Enjoy your tractor, you have a gem there, believe me,(hear the envy in my voice),
Evan.

The gears grate like all that in these tractors but it never seems to
matter. You will soon get used to quick-shifting it up the gears but
not down them! One way of decreasing the pressure on the clutch
pedal is to remove 6 of the 12 clutch springs,Ok if you are not
expecting it to due heavy lugging. Or buy lighter springs they come
in yellow, red and green.I think yellow is the weak type and green
the strong springs,(check this!) But it is quite a job to split the
tractor and rebuild the clutch.
Good luck with your purchase!.
Sam

Thanks for the info it is good to know the clutch is typical.
But now notice it drags enough in low range to move the tractor on level ground with the 1st and even the 2nd stage fully depressed.
Will try to be patient and change gears as recommended.
I have a bad back and knee so a clutch rebuild with lighter or less springs will be the go, good call!
You will probably flame me for this but as I have a 35 SGM in pieces I will use the "spare" clutch lever and extend it by about 200 mm to help me get by.

The problem you have just outlined is a different story all together.
The clutch shouldn't "drag" to that extent. I would say that this problem is a mechanical one, a broken release lever link, oil on the clutch plate or something similar.
Try removing the inspection cover from the underside of the bell housing, and have a look at the clutch with a flashlight. Are the three release levers sitting about the same distance from the thrust bearing? Is there copious amounts of oil inside the housing?
Let us know what you come up with,
Evan.

Hi Sam,
I have to take issue with you there on reducing the number of springs for the main plate. In the UK the 3-cyl 35 and original 11 inch 135 were fitted with 12 yellow springs which gave a clamp load of 1000lbs.
Whilst reducing the number to 9 for example would undoubtedly reduce the pedal pressure required it would not be much use having a tractor that could be used for very light duties only when maybe an urgent heavier job was required. I suspect that if this owner is finding the pedal very heavy the secondary plate adjustments should be checked incase he is partially operating the second stage whilst using the first. The current generation of springs is red. Six are fitted to the 35/135, 9 to the 165 and the full 12 to the 175-188 within the 100 series and 35/65 ranges.
As Evan has said it is necessary to remove the inspection plate regarding drag in case there is oil contamination present. It is a good idea to get into the habit of waiting for the main lever to fall in itself rather than trying to push it.
If more people had adopted this then the number of incidents where the tractor jams in gear would probably be far less.
DavidP, South Wales

Hi, please see my posting below.
I suspect that there is a problem with the clutch linkage or oil contamination which should be checked asap. Which way are you planning to extend the clutch pedal? If it is rearwards you will end up needing a far larger stroke which may not be enough to release it!
I'll throw a suggestion into the pot. If the trailer sign might be a clue and you have access to engineering facilities why not fabricate a hand lever that could be used to assist the pedal operation. I'm thinking of something similar to many ride-on mowers for raising and lowering the cutting deck.
I have a slightly arthritic knee as well. Mine has, I think, been caused by continual clutch operation on a 35 and 135. I have often had an idea for some sort of assisted operation of the pedal by springs or even hydraulic power. If successful there may even be a market for it. We'll agree a deal on royalties later!!!!

DavidP, South Wales

Got some time this afternoon to do some follow up.
The clutch fingers are not perfectly adjusted with about 1.5 mm variation in height or gap.
There is what appears to be engine oil in the clutch housing but the clutch plates appear to be dry.
The clutch drag varies however engagement is always smooth without any judder.
The springs are red, assumes this means it has been rebuilt.
2nd stage adjustment seems ok but needs a closer look.

Couldn't resist DavidP's idea of a hand clutch to save my back and knee as I have spent many hours on a 50CI Fiat Crawler which had a hand clutch.
Quickly knocked up an experimental hand clutch with some 1" pipe and slipped it over the foot peg as a fulcrum point. Already onto mark 2 with an overall advantage of about 6 to 1. Very pleased with the way it works but obviously the design is crude and needs refinement, maybe a cam fabricated from flat bar to push down on the clutch lever just behind the foot peg. The geometry of Mark 2 provides increasing mechanical advantage as the second stage operates
[b:633eaf8c89]Have a feeling someone has done this before![/b:633eaf8c89]
Build time was about 1 hour, note the tie wire holding the foot plate and lever in position Mark 3 will have an a one meter long operating handle, think the most mechanical advantage that can be attained will be about 8 to 1.

A power assisted auto clutch would be the go but without vacuum cannot think how to power it unless I had an alternator with an air pump on the rear end plate

Thanks for all the input.
Looks like I will need to do a rebuild on this clutch and replace some oil seals as the drag is a problem and I don't want to destroy the g/box. However with some careful driving and using the H/L shift as well the rebuild'/split will be a next winter job. Find the trick is to keep in in gear and change into next gear quickly.
Will do a new post or open an old one as I will need some help with this (been 25 years since I assembled a 2 stage clutch)

Used that very crude hand clutch I cobbled together today doing some blading.
Surprises me how well it works. Will make this a separate post later when I improve it if anyone finds it useful. Have a plan to build a hand clutch which will retain the original foot pedal.
However may go down the track of fitting a power assisted clutch from a small truck etc.