Front axle pivot hole worn

[Dextrous]

As Roromac is graciously donating a front axle bracket I thought it was time I got the old one off before the new one arrived. Easier said than done with no lights in the barn and a full schedule this weekend. It was my 3 year olds birthday party today and tomorrow we'll be going to the park to try out her new toys after shopping for safety helmets etc.

I had managed to get the pivot pin retaining plate off in the dark earlier this week. A torch, spanner, lump hammer and chisel and still manage to keep most of my fingers intact! The pivot pin was well and truly stuck though.

The birthday party finished a bit earlier than I thought so I slipped into the barn while it was still light and decided to drop the bracket with the central part of the axle still in place. I dragged it into the workshop for further dismantling after the kids went to bed.

I knew the pivit pin would be a pig to remove, so after lots of lubricating oil I looked around for a suitable tool to drift it out. I looked in the scrap pile and pulled out the old top nut of my dexta steering column. It fit inside the pin and has a shoulder that is smaller than the hole in the casting - perfect

After about 20 blows with a lump hammer the pin was pushed out far enough to remove the axle - thats when my luck stopped

What I thought was the spacer between the front of the axle and the bracket turned out to be the remains of the bush that should be inside the axle. So I have no spacer in front, no washer behind and a oval hole in the axle. Its 48.3mm across the horizontal and 49.3mm across the vertical.

So - its now question time

1.) What is the best way of building up the hole in the casting or do I drill it out and put in a bigger bush? I have already bought a new pin and bush in readiness.

2.) Is it worth fitting a grease nipple while I am at it? The front engine seal is leaking oil however the pivot was still very dry.

3.) What are the dimensions of the spacer and washer? I can probably work it out however I need to get the washer thickness corrrect as the radius arms are a fixed length.

Thanks in advance!
Regards
Andy

[Bensdexta]

Is it worth fitting a grease nipple while I am at it? The front engine seal is leaking oil however the pivot was still very dry.

What are the dimensions of the spacer and washer? I can probably work it out however I need to get the washer thickness corrrect as the radius arms are a fixed length.

Andy,
There is mention of fitting a grease nipple elsewhere on this website. If it is in the upper half of the axle above the pivot, this is normally in compression with weight on the front wheels, so a nipple will have less adverse affect on the axle's strength than if it were fitted below the pivot. Unfortunately the grease is really needed on the underside of the axle below the pivot where access to a nipple is difficult. I wonder if the ocassional swirt with some heavy oil would be as effective as a nipple, with no reduction in axle strength?

Is there a spacer and washer on the pivot pin? It seems the jury is out on this one. My tractor had none. None is shown on the parts list. I had assumed that the fore & aft position of the front axle is fixed by the radius rods? The topic is discussed here: http://www.fordsontractorpages.nl/ubb/F ... 00345.html
http://www.fordsontractorpages.nl/ubb/F ... 00216.html
All the best

[Dextrous]

Thanks Ben

I should have searched the old site first - I will next time

I was looking for the washer and spacer as these are on the parts list I downloaded from Stefans site. The design doesn't seem logical to me without these as the twisting forces will make the axle cant over with pin wear putting stress on other components and there is nothing the retain the bush so it can twist out like mine did.

I think if I get the washer and spacer in place and add a bit of oil occasionally then I'll forget the nipple.

Looks like a vist to my dad's lathe is in order.

Regards
Andy

[Bensdexta]

I was looking for the washer and spacer as these are on the parts list I downloaded from Stefans site. The design doesn't seem logical to me without these as the twisting forces will make the axle cant over with pin wear putting stress on other components and there is nothing the retain the bush so it can twist out like mine did.

Hi Andy,
I don't see any washers/spacers on Stefan's parts list, nor on the CNH parts list:
http://partstore.agriculture.newholland ... 97ag119097
I don't think spacers will help prevent the axle from trying to twist about the transverse horizontal axis. This twisting moment arises from the back swept geometry of the front axle. I think this is probably why most Dextas have banana-shaped radius rods, bowed upwards, as it's these rods which prevent this rotation as well as locating the axle fore & aft. I've had my rods straightened on a press - look alot better, hope they stay straight

I can see that spacers in the axle pivot will help locate the axle fore&aft which may take some of the load out of the radius rod ball joints, another popular Dexta wear point. But as you mentioned earlier, the spacers would need to be just the right thickness, not to put more load on the ball joints. As you also say spacers will ensure that the axle bush stays put.
I think I'll try without spacers initially and monitor for movement & wear. If you do fit spacers, I'd be interested to know how you will decide their thickness. It looks like some 1 3/4" washers would serve, but I wouldn't pack in too many as lack of any fore & aft movement of the axle on the axle pin could cause the axle to bind.
All the best,

[Dextrous]

Hi Ben

I thought I was going mad for a second - I could have sworn there were spacers in the parts list.

So I looked in the workshop manual (1958) and there they are!
Page 1 of the front axle section. I knew I had read it somewhere.

In removing the trunnion pin section it says keep the spacers in their original order, and in replacing the trunnion pin section, it says that the large spacer is fitted in front of the centre beam and the others behind it.

So I think I will have to assemble it first and measure clearances then make up some spacers and refit it. may be a while until I get to this stage.

If somebody can measure the front spacer - if anybody has one left! Then I could make one of these and work out the size of the remaining space and make a few thick washer on the lathe.

These parts are not the only bits missing form the parts lists downloaded from this and Stefans site - I have yet to find the front wheel hubs!

Regards
Andy

[Dunggatherer]

Hi Dextrous,

A few years ago i was facing the same problem.
Now i don't own a lathe,so i went to the store and got an M45 washer.Some 5 mm thick.
This i ground with an angle grinder to a thickness of about 3,5 mm.
That was all that was needed.

Greetings from the Netherlands.
Rob.

[Dextrous]

Many thanks Rob

I don't want to use the lathe unless I have to as I would need to travel to my fathers house and then take all the junk that has accumulated on the lathe off etc. etc. so the washer sounds the way to go.

Could I ask you a favour? Could you measure the length of the spacer that fits in front of the axle? Outside diameter would be useful too but its the length that I need the most.

How much free play does your spacer/axle/washer set up leave for backwards movement of the axle as it twists about the radius arms?

Best regards
Andy

[Dunggatherer]

No problem.

When i bought the tractor i found a lot of free play in the front axle suspension.
There was only one washer (spacer?) present,and indeed that sat in front of the front axle.
The inside diameter is slightly less than 45 mm (that's how i got the idea of buying a washer).
The outside diameter is almost 75 mm.
The thickness (is this what you mean by length?) less than one mm.
It could be this is not original,could be it's all that's left after all those years...
But it does fit snugly around the frontaxlelocating pin.
And it leaves no room for the axle to move forward once the tractor is put in reverse.
This was important to me as that would put significant strain on the balls at the ends of the radius rods.
All there was left to fix was the play at the rear of the front axle suspension.
That was 3.5 mm so that is how thick i left my washer.

Does this answer your question?

Greetings from Holland.
Rob.

Edit: this setup leaves no detectable room for movement of the axle,and i'm happy with it because of the mentioned strain.
I must add however that when i installed the parts i made sure i was able to rock the left and right front wheels up and down easily,that's pretty important too...

[Bensdexta]

this setup leaves no detectable room for movement of the axle,and i'm happy with it because of the mentioned strain.
I must add however that when i installed the parts i made sure i was able to rock the left and right front wheels up and down easily,that's pretty important too...

Rob,
Thanks for the explanation, very helpful.

Is it your impression that most of the fore&aft loads on your front axle are carried by the washer & spacer you have fitted on the pivot pin - and NOT by the radius rods?

Also from your last sentence, I understand you jacked up the front end and rocked the front axle about the pivot through its full range of movement, to ensure that it moved freely? I assume you did this with radius rods installed? When you did this did you notice any fore&aft movement in the axle arising from the radius rods as their geometry changed?

How much fore & aft play do you have in your radius rod ball joints?
Many thanks,

[Dunggatherer]

Well,given the fact that the axle is sort of tilted,i would say the pin and washer and spacer prevent the axle from turning up and down.You can tell by the way it's wearing and tearing.
If the radius rods are in good condition they can prevent the axle from sliding fore and aft along the locating pin,even if the spacer or washer are gone.

When rocking the axle i did not see the axle moving fore or aft.
I did see that the angle of the axle in its cradle slightly altered,but that was not much since i renewed the pin and bushing too,although the fitting of the pin was a breeze,so there must be some room there.

The radius rod ball joints are original,and were in remarkable condition.
I would say that if there was any play it would be less than 0.5 mm

I do think however that the design allows for some play,as when you regard the system mathematically you have no other option.
The radius rods are a fixed length,so when the axle moves,tilts,or rocks there MUST be some play around the center pin.

[Bensdexta]

Rob,
Many thanks for the explanation. Makes sense to me.

So the consensus is that the pivot spacers are a good thing, but we need to leave a bit of play in there.

It's also wise to do a 'full and free' movement test of the axle, with wheels off the ground, after all the parts are fitted.
All the best,

[Dextrous]

There was only one washer (spacer?) present,and indeed that sat in front of the front axle.
The inside diameter is slightly less than 45 mm (that's how i got the idea of buying a washer).
The outside diameter is almost 75 mm.
The thickness (is this what you mean by length?) less than one mm.
It could be this is not original,could be it's all that's left after all those years...
But it does fit snugly around the frontaxlelocating pin.
And it leaves no room for the axle to move forward once the tractor is put in reverse.
Does this answer your question?

Hi Rob

From memory with the radius arms fixed the axle was very close to the rear of the bracket so 3.5mm sounds about right, however there was over 50mm of pin showing between the front of the axle and the front of the axle bracket. This is where I need the spacer as shown in the workshop manual. so 1mm seems a bit thin for the front spacer. I've dismantled it now but I'll have a new bracket soon then I'll post pictures unless Ben beats me to it!

Regards
Andy

[Tubal Cain]

This subject has been discussed on the earlier site and I posted a photograph of an axle and carrier assembly with washers or spacers fitted.

If you analyse the forces acting on the axle in way of the pivot pin and examine the wear pattern on both the pin and the bushes, it is evident that the axle twists about the longitudinal axis of the pin. This is exacerbated when a front loader is fitted and in severe cases the bushes in the carrier will also be badly worn. Any ovality in the bore of the axle should be removed; as the thin walled bushes require to be supported and will quickly fail if fitted in an oval bore. Similarly any ovality in the bores in the carrier will allow the pin to rattle which in turn will lead to accelerated wear of both the pin and bore.

By fitting spacers between the axle and carrier both front and back these forces will be transmitted to the carrier and thus limit the wear on the pin and bushes.

In order to determine the thickness of the washers I would suggest that the following procedure is followed: -

Assemble the axle and carrier on the tractor and fit the radius arms.

Move the tractor backwards and forwards to ensure that the components have settled into their normal position.

Measure the clearances between the axle and the carrier to obtain the thickness of the washers.

If you have access to a lathe the washers can be turned to the required thickness otherwise you will have to fit washers of a nominal thickness. Ideally the clearance should be minimal, just sufficient to enable the axle to pivot on the pin.

As the axle pin bush is plain the ideal place to fit a grease nipple is on the bottom of the axle to ensure that grease reaches the area where the maximum load acts. This can be achieved by drilling a 3/16” hole through to the axle and brazing a copper pipe in the hole, the other end led to a suitable access point and a grease nipple fitted on the end. I doubt that a small round hole in this area would compromise the strength and integrity of the axle.

As I have access to both a lathe and milling machine my own solution for repairing a badly worn carrier and axle is to bore out the bores in the carrier and axle to remove the ovality caused by wear. Then manufacture oversize bushes to suit the new bores, with an internal bore to suit the standard axle pin, which incidentally is hardened. If the bushes in the carrier are flanged, the thickness of the flanges can be adjusted so as to act as spacers for the axle and will also retain the bushes in position.

Gerald

[Dextrous]

Thanks Gerald

According to the workshop manual the front spacer is of a fixed size, hence why I have been asking what length it is. The rear spacers are used for adjustment. However in their absence I see no reason not to follow your methodology. I wonder if this is a good enough reason to buy a lathe - not sure I can convince my other half!

The ovality on mine is about 1mm so I was wondering if Belzona would be suitable http://www.belzona.com/prod1k.aspx#msds_flyers It mentions building up of oversize bush and bearing housings. Although I would prefer to bore it out as you describe.

Regards
Andy

[Dunggatherer]

Unbelievable!

After reading your reply i went to the daily driver,and took a good look.
This Dexta i bought some 6 years ago and it was my first one.
I compared this with the one i am currently restoring,and is now in parts.

Apparently a piece of pipe was welded into the cradle to sort of lock up the axle.
Only some 5 mm room was left.
The weld looks very Fordish,so i guess i never gave it a second thought...

So thanks for the reply and sorry for all the incorrect measurements.
Seems you helped me much more than i helped you.

Good luck!
Rob.

[Bensdexta]

Gerald,
Thanks for your post on this tricky subject - I wondered where you were! Here's my two penny-worth!

When you say "If you analyse the forces acting on the axle in way of the pivot pin and examine the wear pattern on both the pin and the bushes, it is evident that the axle twists about the longitudinal axis of the pin," are you referring to twisting of the axle arising from its backswept geometry? I think this is a twist about an axis transverse to the pin.

As you say this effect is exacerbated by a front loader when the forces involved will be quite large. I wonder if packing the axle tightly fore&aft at the pivot with spacers will do much to resist the torques involved? It seems to me that this twist is largely resisted by the radius rods with their 3' 6" lever arm, and this is why on most Dextas they are bowed upwards. I guess that bowed rods goes with ovalised pivot bushes?

One other thought: If the radius rod ball joints lay on the tractor's centreline, then the centre of the front axle would have a unique longitudinal position (assuming no play in the joints). In fact the ball joints are offset from the centreline, so the front axle will move sligthly backwards as the axle pivots to the extremes of its position. If the tractor is only ever driven on roads this effect will be small, but on rough terrain it could I think move by the odd mm - one would have to test to see. Perhaps a reason for not packing the pivot pin very tightly with spacers, unless one allows some play in the ball joints.

All this makes for a good discussion!

I guess a basic test is to check that when fully assembled with wheels off the ground, the front axle has full and free movement, without undue rattle. Then to monitor wear in service.

Is it possible to dig out the photo you mention, as I can't find it on the old website?
Many thanks,

[Dextrous]

Unbelievable!

After reading your reply i went to the daily driver,and took a good look.
This Dexta i bought some 6 years ago and it was my first one.
I compared this with the one i am currently restoring,and is now in parts.

Apparently a piece of pipe was welded into the cradle to sort of lock up the axle.
Only some 5 mm room was left.
The weld looks very Fordish,so i guess i never gave it a second thought...

So thanks for the reply and sorry for all the incorrect measurements.
Seems you helped me much more than i helped you.

Good luck!
Rob.

No problem Rob - its been a good discussion - I think I may replace mine with roller bearings so I can have the best pivot on the forum
Regards
Andy

[Dextrous]

For future reference, not accounting for any wear and manufacturing tolerances, the distance between the front and rear of the carrier where the axle sits is 63mm and the axle is 38mm thick so 25mm of free play to be taken up with spacers/washers.

Most of the free space is to the front of the axle, typical washer sizes behind the axle have been quoted as 3 and 5mm. So you can probably make a 18mm long spacer in advance for in front of the axle and take up the remaining slack with washers as per Tubal Cain's suggestions earlier in the thread.

Regards
Andy

[edited as I made a cock-up of the meaurement - gap is 63mm not 57mm - I accidentally measured to the old pin that I hadn't completely driven out - I'll admit my eyes are getting old and get glasses soon!]

[Tubal Cain]

Andy,

Please ammend your last post to read Tubal Cain's suggestions rather than directions!

Gerald

[Tubal Cain]

I have found part nos. for the spacers in one of the parts manuals which I have.

They are 957E-3024 for the front spacer and 957E-3027 for the rear spacer.

Unfortunately there are no dimensions listed.

Gerald.

[Bensdexta]

For future reference, not accounting for any wear and manufacturing tolerances, the distance between the front and rear of the carrier where the axle sits is 57mm ....

This distance on my 'new' carrier is 67mm. My old carrier, which has been cut about a bit, looks like it was much the same.

So it looks as though the spacers need to be tailor made for each individual carrier/axle.
All the best,

[GERRY]

i have just been reading your posts , idont know if this is of any use now as you have probly sorted ou the washers but i have one of the washers which have taken offa58 dexta it is the thick one , it is 16mm thick and it has amachine cut through it although it is rusted this will give you some idea of the thickness of the big washer if its not to late for you, GERRY

[Stefan]

My Dexta is still fitted with her original spacer. I installed the front axle and installed the radius rods and then checked the gap. I fitted a few washers to have a bit free-play for the axle. The free-play is about 1 milimeters.

Stefan

[Bensdexta]

My Dexta is still fitted with her original spacer. I installed the front axle and installed the radius rods and then checked the gap. I fitted a few washers to have a bit free-play for the axle. The free-play is about 1 milimeters.

Sefan,
Thanks for the great photo - very helpful
Can you tell us the thickness (length) of your big spacer, in front of the axle?
Many thanks,

[Dextrous]

For future reference, not accounting for any wear and manufacturing tolerances, the distance between the front and rear of the carrier where the axle sits is 57mm ....

This distance on my 'new' carrier is 67mm. My old carrier, which has been cut about a bit, looks like it was much the same.

So it looks as though the spacers need to be tailor made for each individual carrier/axle.
All the best,

I've edited my original post to say "suggested" instead of "directed" by Tubal Cain

I've also amended the distance as I had a senior moment when I measured it the first time - the gap is 63.3mm. having said that, this is my old carrier that has had a bit of "surgery" on it so it is only indicative. I'll measure the new one soon.