Replacement lift arms

[smchris]

Dear all

I have a problem with one of the lift arms on my Super Major (1961);

These are the parts: https://agrilineproducts.com/ford-fords ... lh-rh-4225

I had a heavy implement on the tractor (hedge cutter), and the split pin in the main pin coupling the lift arm broke, allowing the pin to fall out halfway, which bent the linkage on the arm, and the pin. I heated it and bent it back into alignment, and made a new through-pin.

All looked good, for about half an hour... The lift arm just suddenly broke on the bracket in two places. Obviously weakened by the prior trauma, and my heating it.

I phoned agriline and they sold me a pair of the above-listed arms (I bought two, reasoning that the other side would probably go next and so it would be good to have a spare). They assured me these would fit.

The new parts have come and are a good match with the originals and seem to be well made, except that the spline pattern does not seem to match. It absolutely will not go on; my original part slides on and off the splines easily, and the splines themselves are not fouled, so it seems mismatched.

Looking more carefully, the new part seems to have a wider "flat patch" on one position than my original. I cannot understand the poor fit, since this should be the correct cross-shaft compatible part for Super Majors.

Has anyone been down this road before, or can offer me some guidance please?

Chris

[Billy26F5]

Sounds like the usual aftermarket problem is back. Original arms will work, see what you can find. As for the repro ones it's as Brian says in the land of nearly right, so if you want new ones you'll need to replace more parts, not something I recommend. Once you have the arms fit them without o-rings, tighten the bolts until the arms just drop under their own weight, count the turns then assemble with the o-rings to the same position. Not doing this will result in poor depth control.
As for your repair it sounds like the typical issue from heat, these things can be done but only with correct treatments to restore the strength (not easy especially without suitable tools).
Sandy

[smchris]

Thanks. It must be that the spline pattern is different on the cross-shaft; my concern is that if I replace the cross shaft to match the arms, it probably won't match the the mounts inside the rear end.

Is there a way to machine the new arms to work? I don't have any way to cut splines, so I'd need specialist help with this...

Meanwhile, if anyone has any original arms they can let me have, please say.

[smchris]

Looking further, in this picture, the cross shaft has a flat, intended, presumably, to align with the flat on the lift arms.

This is an example: https://www.ebay.co.uk/itm/202683777851

But my cross shaft does not have these flats: it's splined all around.

So is mine not the correct SM cross shaft? Was there an earlier / different design? Has mine got a part from an earlier tractor on it?

Anyone know?

[mathias1]

I did use a new shaft with old arms nd that just went alright. No experience wth the new arms they make
You might better look for good used ones

[Billy26F5]

Can you post a pic? I've never heard of them not having the flat, as otherwise getting the correct position is a hard job. What do the arms look like? I think you might have a bigger job here. Give everything a clean, you might be surprised with what you find.
Sandy

[smchris]

Images of the old (blue) and the new (dark red)
https://ibb.co/gjrc66t
https://ibb.co/bQQzBgf

I cannot see any obvious corresponding flat on the splined cross shaft; tried a range of orientations for this arm and it does not want to go on. The original slips on and off easily, which, I gather, is a rarity for these things!

[John b]

Take the new arms to an engineering shop and get the flats milled deeper than the splines so they will go over the cross shaft, not a big job. Then using the old arms as a guide you should be able to get the orientation correct

[smchris]

Hi John

Good suggestion, and I thought of that; but the only issue is if the spline separation is out wrt to the original. I've not measured it yet (not had a chance and it was too cold!) but that's going to be my next move; I've actually been toying with the idea of getting a mill anyway, so it might end up being DIY! Otherwise, I do have a friend with a professional shop that could template off the original to mill down the new... I'm more intrigued by how I've ended up with what seems to be a Frankenstein tractor!

[Billy26F5]

All good things, looking at the pics it seems the arms have opposite flats (recess on the arm on the original, on the repro it's on the shaft). If you do get a mill just cut into the flat, but do check everything else first as if the sizes are not all right you'll need an original arm anyway. It looks to me like Ford left out one spline. The repro arm seems to be two, and not in quite the same place. Original remains best. We were lucky too on one of our half Super Major ones, the other one was a bigger battle.
Sandy

[John b]

If you mix a big lump of car body filler, spray some wd40 on the splines in one of the old arms so it will release and press the filler about 1/4 of the way round the inside you should be able to remove it when it hardens and use it to see if the splines match up in the new arms

[Billy26F5]

Sounds like a good idea, a pic of the shaft would be nice too. I'll check ours as well.
Sandy