Fordson SM Clutch Play

[shepp]

Looks like your seal is the earlier metal case type, the replacement will be conventional rubber over steel. This might be slightly wider than the original seal, if you look in the workshop manual it refers to the need to drive the brass bush slightly further into the PTO drive shaft housing using a special tool that probably no one has access to in order to fit the latest replacement seal. Be careful.

[Billy26F5]

The special tool could probably be made easily enough from suitable pipe. The drawing looks accurate enough but I would measure both seals and then move the bush the appropriate distance to keep the lip in the right place.
Sandy

[smchris]

I've got the seal out; a screwdriver down the side of it bent it in and I could then prise it out from below; now it's out I'm not actually sure what sort of seal it is, old or new. What's left of it is the usual steel outer with a rubber inner (or what was once a rubber inner - it's totally worn away).

I'll order the replacement and then compare the depth of the two to decide what to do next...

Thanks for your help so far.

[Billy26F5]

You've got the early type, the later type is all rubber on the outside.
With the new one the oil leak should be gone for a while, a very satisfying result.
Sandy

[smchris]

An update on my progress:

I have replaced the seal on the gearbox input from the PTO / drive shafts; I've also replaced the small seal inside the PTO drive that surrounds the main drive shaft. It came out okay by bending it inwards with a screwdriver and then knocking it out. The replacement went in with a socket just smaller than the shaft dia to drift it in.

All horrendous oil, grease, clutch muck etc cleaned from bell housing and from crankcase behind flywheel, and crank upper rope seal replaced. Disgusting job.

New dual clutch (cast iron replacing previous aluminium one that had cracked apart) installed. Bit of a pain lining up the splines and the driveshafts and getting the front of the tractor to roll back on cleanly, but eventual triumph.

Now I have one job remaining (for now!), and this is where I need some advice: the front timing cover oil leak. I suspect the gasket rather than the seal, so I need the cover off.

I currently have the nose cone and the radiator out, so I can see the pulley and the crank nut; so what is the best, least painful, least accident-prone way into that cover?

[Billy26F5]

Have you tried checking if the bolts are tight enough? I suggest you try that first, but if that doesn't work prepare for removing the cover by getting the tractor in top gear with the brakes locked on before you start, then remove the rachet bolt from the crank. You then really want a puller that can thread into the pulley holes for this (I just cleaned them up and they're 3/8" coarse thread probably UNC but not sure as I used a bolt from our half Super Major for it) as the pulley is a tight fit and pull it off. Check the pulley hub as I suspect your seal will be leaking, if there's a deep grove there's very likely a leak. Now remove the cover and examine the seal, I would replace it anyway at this stage. Inspect the gasket face while you're at it and I would look at the timing gears just in case they need something (hopefully not) then reassemble and remember not to overlook servicing the breather (I suggest you drain it once the cover comes off to avoid a nasty mess, don't refill it until the cover is back on).
Sandy

[John b]

If you remove or re-tighten the timing case cover bolts use a torque wrench, the bolts are only tightened to 12 ft/lbs (but check that figure in case i'm wrong). They are very soft and can snap off in the block easily if over tightened

[smchris]

Thanks both.

I have borrowed my neighbour's Stillson wrench, and I have a pulley puller that should get me into those holes okay.

The problem I have is how to jam the engine? I have tried putting it in gear and locking on the brakes, but the engine just turns.

I need some safe way to jam the crankshaft.

What do you advise please?

Chris

[John b]

I have done it in the past by removing the starter motor and getting someone to help me by jamming a piece of 2" x 1" batten against the starter ring gear while I undid the bolt. A ring spanner on the bolt and a good belt on the spanner with a heavy mallet will sometimes be enough to undo it

[smchris]

Thanks.

I thought of doing that, but removing rhe starter is a faff and I was hoping for a shortcut!

If I had the front off and could get an impact on it, that would solve it, but removing the front axle seems a bit extreme just to get a timing cover off!

[Billy26F5]

I would try the spanner and hammer method, but definitely try to put all the braking you can manage on, as in put on the handbrake if you have one too, perhaps chock the wheels too to help resist any temptation to move. I would expect the hammer to do it easily with all that and I agree that removing the starter is a bind, so I would leave it on till trying to lock everything fails. Good point to remember the torque setting, and getting the sheared bolt out is not fun (Super Billy had one and it took quite a battle to get out).
Sandy

[shepp]

Conventionally the starting handle dog nut should be a left hand thread not a right hand thread as the engine rotates clockwise when viewed from the front, but Its been a long time since I had one off and I can't remember if this is the case on the Major, but check it out by trying to undo the nut clockwise carefully!

[Billy26F5]

The Major one is a normal very fine thread, the only LH thread in a Major is in the rear axle.
Sandy

[Old Hywel]

Conventionally the starting handle dog nut should be a left hand thread …

Can’t see that being the case anywhere, since vigorous use of a starting handle could undo the nut.

[Billy26F5]

Can’t see that being the case anywhere, since vigorous use of a starting handle could undo the nut.

Agree 100%.
Sandy

[shepp]

What I was meaning to say was that conventionally a nut or bolt that is spinning at high speed holding something on that rotates quickly clockwise is usually left hand thread as it counteracts the tendency of the nut or bolt to come loose, an example is the offside wheels on a truck where the wheel suds and nuts are left hand thread, conversely the nearside wheel studs and nuts are right hand thread. It was just a thought that might have helped!

[smchris]

Update for you.

Tractor is all back together, and works!

I took the starter off and put a pry bar into the ring gear to jam the engine in the end.

The starter nut is a conventional thread, as suggested above. The pulley came off easily with a ducksfoot puller, but just fiddly owing to restricted room.

I replaced the timing cover crank seal and the gasket.

But, there's still an oil leak. It's coming out between the plate the timing cover mounts to and the block.

Can someone advise what sits between the two that might be the source for this leak? It cannot be ignored because it's a significant one.

When we did the engine rebuild, we replaced the sump gasket, so I don't think that is a likely source, but what else might be doing this?

[John b]

There is a gasket between the plate and the block, there are 2 different types of gasket depending on which type of camshaft retainer you have ,the engine rebuild gasket kit contains both type of gasket. You will have to remove the pulley, cover, timing gears and front plate to do it. I'm pretty sure you will have to remove the tombstone too as the plate mounts to the side rails and as far as I can remember it won't come off without taking the front off and losening the side rails. Once you have the front plate off you should be able to see which gasket it is, one has a slot to let oil get to the end of the cam as the plate acts as the thrust face for the cam (super major), the other has no slot as the cam has 2 horse shoe thrust washers that hold the cam in place and is oiled from inside the block (earlier engines). When you remove the front plate make sure you note where the bolts came from, some are longer and there are UNC and UNF threads used. They need to be tightened in order and as with the cover, make sure you use a torque wrench, and you will need locking wire for them too

[smchris]

Thanks for the detailed reply, John. God this job just keeps getting better! So I'm taking it all apart again, by the look of it! Grrr.

Does the tombstone come off without taking the axle apart, or do I need to undo the rails and pull the front end away?

[John b]

If you have an engine crane you can remove the front wheels and steering drag link and lift the whole thing away from the front in one piece, but you will need a strong assistant and be careful it doesn't swing into your legs, it's bloody heavy!

[John b]

Thinking back to when I last took one off I left the wheels on. Jack the tractor up so the weight is off the front wheels but they are still just touching the ground and support it under the gearbox. Take the weight of the tombstone on an engine crane, remove the mountIng bolts and steering link, have someone on each front wheel roll them forwards clear of the tractor

[smchris]

Ty

Do you know what that gasket is called? I can see what must be it in the rebuild kits, but I don't need the half dozen other gaskets in the pack, having down all the other jobs already. Would be useful to know so I can order the right thing (taking I to account your point about two different designs. This is a super so it should be the later one).

Chris

[John b]

Timing cover rear plate gasket. If your cam shaft has a single bolt holding the gear on (as opposed to the 3 smaller bolts on the early one) it should be the gasket with a slot. Are you in the UK? If you are I may well have one I can post to you if you have trouble getting one without the kit

[smchris]

Hi John

Yes, I'm in Essex; you kindly helped me out with a fuel cap a couple of years ago - mine was non-standard and blocked, so the tank was vacuuming and stopping the engine... until you assisted!

If you do have one of the correct gasket going spare, I'd be extremely grateful. The other thing that is confusing me is the reference to "packing material"; as far as I know, we just fitted whatever was in the gasket set for the sump gasket that turned up from Agriline. I didn't realise at the time there might be different formats. But looking at the shop manual, it talks about different packing for the different models. I hope we got the right one in there. I presume this is the strip of cork that sits in the curved depression at the front end of the sump casting?

Thanks for your patience answering all these questions.

[John b]

Ahh yes sorry Chris, I'm terrible remembering names! It can be a bit hit and miss with some of the gasket sets and what they contain and it's not always clear what to use. If you have had it running see if there are any signs of a leak at the sump. Can you see where the leak is between the plate and the engine block?