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Discussion Starter #1
I have a Ford 7700 tractor that was leaking from the steering orbital. I fitted a new shaft seal and brass ring to the input shaft, and a new cylindrical rubber sleeve to the rotor end. One of the o-rings was not supplied and didn't exist in my o-ring kit, but it looked okay and so I re-used the old one with a tiny smear of gasket silicone. Shaft was rather worn, but there wasn't much I could do about that.

I refitted it to the tractor, and the leak is fixed. However, the steering wheel is now slightly stiffer than it was before. Steering effort is the same in both directions. The hoses were marked before removal and are connected to the same ports. I've used it enough now to think that all the air should be out of the system. I didn't remove the torsion bar and so the setting of that shouldn't have been upset.

It's usable as it is, but it's just not quite how it should be.

Any ideas?
 

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Most likely the problem lies on the bottom end not the input shaft.
Did you rotate the input shaft as you tightened the bottom bolts to collapse the rubber seal?
Bottom bolts torqued to proper spec?
 

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Discussion Starter #3
Most likely the problem lies on the bottom end not the input shaft.
Did you rotate the input shaft as you tightened the bottom bolts to collapse the rubber seal?
Bottom bolts torqued to proper spec?
I didn't use a torque wrench for the bottom bolts. I did them by hand but didn't go overboard because they seemed like they weren't very tight when I undid them.

I didn't rotate the input shaft as I tightened the bolts either. Didn't realise that I should. I was a bit dubious about the cylindrical seal as it looked too long. I checked with the supplier and he said that it was the correct one. So I fitted it and watched as I evenly tightened the bolts, and it seemed to go in nicely without pinching or anything.
 

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And there lies the problem.
The seal looks too long by a 1/8 inch or so that's the correct length.
You must rotate the input shaft while tightening the bolts to align the gerotor end and use a torque wrench.
Doing this in steps is best, not full torque on the first bolt.
 

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Discussion Starter #5
And there lies the problem.
The seal looks too long by a 1/8 inch or so that's the correct length.
You must rotate the input shaft while tightening the bolts to align the gerotor end and use a torque wrench.
Doing this in steps is best, not full torque on the first bolt.
Thanks for the info. You would think the seal would come with instructions if it's an important procedure but it didn't. So, is it salvagable or is it too late?
 

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If you pull it out of the tractor again just loosen the bolts on the bottom and retorque in a sequence like you would a wheel. Do it in a few steps with the final torque at 19ft lbs. Keep rotating the input shaft back and forth as you do the bolts up. Sometimes if you slid the georotor out of the stator and inadvertantly put one of the parts upside down to origanal it can cause tightness as well.
The torque value is cast into the bottom plate of thr orbitrol on some units.
If it is tight out on the bench it will be the same in the tractor.
 

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Thanks for the info. You would think the seal would come with instructions if it's an important procedure but it didn't. So, is it salvagable or is it too late?
Oh yes everything should be fine.
I would remove the steering hand pump place it in the vice and clamp lightly by the main body and loosen the bottom bolts off and rotate input slowly while retightening the bolts to the proper torque.
 

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Discussion Starter #9
Thankyou very much for the suggestions.

I have loosened the bolts, then slowly and evenly tightened them while rotating the input shaft, now it's back to working like it should.

Thanks again.
 
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