The Fordson Tractor Pages Forum

As soon as I started driving my Super Dexta today, it began making a clanking/ratteling noise. The noise seems to be coming from either the clutch are, or the forward part of the transmission. I replaced the clutch, throw out bearing and pilot bearing last year. The clutch still works fine. The noise is the same in all gears, both high and low range. It is also present in reverse. The noise is not constant, but it is very often.

I recorded it with my cell phone and posted it to Utube, if anyone can identify the problem I would be very grateful.

http://www.youtube.com/watch?v=5O1oFKdxIww

I am afraid to drive the tractor until I correct this problem.
Thanks,
Terry

That sounds like something loose inside the clutch. I would have said an operating lever.

It could be on the PTO clutch so you don't notice it on the main clutch which would work OK.

Could you have left a spanner or something inside when you last had it apart?

It does need urgent investigation.

Thanks Brian,
I don't think I left anything inside. The noise started as a metallic clank, then turned into the knocking, thumping noise you hear on utube. It has been a year since I replaced the clutch.
The PTO clutch still works.
I will begin to take it apart this weekend.
Terry

I split the tractor, the clutch appears to be fine. No broken springs, all levers tight and seem to be at the right hight. No missing or backed out bolts. The release fork and spring look good. No sign of anything amiss.
I am very afraid the noise is coming from the transmission. I am going to look at the manual to see how to proceed.
Terry

That is a bit of a let down.

Where were you holding the phone to record the noise?

Does it stop when you put your foot on the transmission clutch or the PTO clutch?

If its there in all the gears and even when the tractor is not in gear it may be in the front part of the box, something like the input shaft bearing which you can get through the clutch housing.

Hi Terry,

Can't find out anything usefull on utube, to bad computer here I think.

Have you checked the pilot bearing in the flywheel? Is the sound relative to the engine speed or to the driving speed? And does it stop when you disengage the clutch? That might help identificate the location of the sound.

Otherwise: Do not drive or run the tractor unless really needed. We once had a little accident with a Lanz Bulldog. In the rear axle housing it dropped a ball from a bearing, without giving a accoustical note in advance. The ball fell into some meshing gears and destroyed half of the gears in the tractor. That wasn't fun to repair.
In other words, do not take the risk before investigating.

Best regards

Emiel

Brian, the phone was at the back of the clutch housing where it joins the transmission.
The noise stops when the tractor is out of gear, I think. I quit driving the tractor after a very short diagnostic run.
I will check the input shaft next.
Thanks,
Terry

I have removed the PTO input shaft. No problems that I can see, not a lot of wear on the gears.
The big PTO gear can be moved from the back to the front of the tractor. This is the gear driven by the PTO input gear. The movement is approximately 1/8 to 3/16 of an inch. (3 or 4 mm). Is this too much movement?
When I turn the shafts by hand, they turn smoothly and quietly.
I seem to have eliminated everything except the transmission. This is the one thing on the tractor that I fear to tear into.
Terry

The shaft with the big PTO gear seems to have a bad bearing, I can move the shaft up and down about 1/2 inch, definably too much.
Trying to get the brake cross shaft out, the square key that is in the shaft is so stuck that I don't know how I can get it out.
Terry

Terry,

The key in the brake shaft should be a woodruff key ie. half moon shape. If you gently tap one end of the key you should be able to get it to turn in the keyway and eventually remove it.

The last resort is to try and remove it using a punch or chisel to force it out of the keyway/

Gerald

Tubal Cain, I got the woodruff key out. I had to get rough with it, used a chisel and destroyed the key. The shaft is in good shape, which is the important thing.
The clutch housing is removed and the gears are all clearly visible. The bearings all seem to be good.
I believe the big PTO gear is sliding on the shaft and making the noise that I hear. I am not sure how it is supposed to go back together. It has a cir clip still in the gear, the cir clip does not seem to have been in a slot. What are the slots in the face of the gear used for?





There is a slot in the shaft for a cir clip, but it is on the front side of the bearing, not the rear side where the gear is.

Terry,

The slots in the face of the gear are used when the tractor has a non-live drive PTO when a coupling is fitted to the end of the shaft, which locks the gear to the shaft. This is shown in the workshop manual item 44 Fig. 5 and Fig. 15, or in the parts book Fig. 28 item 48.

The polished area on the component shown in your second photograph suggests that the inner race of the bearing is loose and slipping on the countershaft!

I have a gearbox stripped down in the workshop, I will have a closer look at it and come back to you.

Gerald

Tubal Cain, can you tell me the dimensions of the thrust washer, part #C7NN-B777-A, item # 17 on page 84 of the Dexta parts catalog? I need to find one, I am going to call the New Holland dealer tomorrow. If it is no longer available, I will need the dimensions to find a suitable replacement.
What do you suggest I do about the polished shaft?
Thanks, Terry

Terry,

I had a senior moment, at close on three score and ten years I should not rely on my memory. Having checked the gears I can inform you that the slots to which you referred are not used as I suggested. In fact the coupling engages with the teeth on the gear shown in your 2nd photo, and so provides rotation to the PTO in non live drive mode.

With reference to the thrust washer, I cannot find it at the moment but as it acts as spacer I would suggest that you measure the distance between the inner race of the bearing and the face of the gear with the circlip fitted. You can probably get one machined.

The fact that the inner race of the bearing would appear to be loose on the shaft will make the above operation easier. If Loctite is applied to the bearing inner ring, on final assembly, it should prevent the race from turning.

I did take some photos but, they haven't turned out too well, also I'm having trouble uploading them on to Photobucket.

Gerald

Just an update, the slots in the PTO drive gear are to enable the special puller shown in the workshop manual to act on the inner race of the bearing when removing it. Pulling the bearing off by applying force to the outer ring may result in damage to the bearing and is not considered to be good practice.

Gerald.

This is an update to the outcome of my problem
I have the tractor back together and have not heard any strange noise. I have run her through all gears and everything appears to be well. The only thing I have done that might have fixed the problem is, I installed a missing snap ring on the end of the PTO counter shaft.
Here is what I believe happened. One of the previous owners had the tractor apart a long time ago and put it back together without the snap ring. The bearing is in a blind hole and he probably thought the snap ring was not needed. The gear box oil was not changed in a very long time. When I changed the oil, it softened the varnish and allowed the bearing to shift away from the PTO gear. The PTO gear could then move, and that movement is the noise I heard. With the snap ring in place, the gear is held steady.
This is all just a theory, but the noise is gone.
Terry

Well done Terry. What was it that the famous detective Sherlock Holmes used to say "eliminate the possible and what you have left, however improbable, is the answer" (or words to that effect).

|I was talking with a farmer yesterday, about the time I stripped the whole back-end of a new Ford 4000 which had developed a knock within its first 100 hours. It belonged to the father of the boy who was my understudy at the time. I drove it up the road and came back very quickly as I thought the whole back end was going to fly apart any second.

We started at the wheels and worked our way through to the clutch checking everything, epicyclics, dif. bearings, gearbox bearings, the lot. All we had left was the outer housings and a heap of bits but could find no fault. So we rebuilt it using all the "old" bits.

Took her down the road, no noise.

That tractor never gave anymore trouble.

We thought that Fords had overtightened the pre load on the crown wheel and pinion and we corrected it when we rebuilt her.