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WW1 Thornycroft restoration


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Until ball joints replaced kingpins (around the 1970’s / 80's, if I remember correctly) a lot of lorries and heavier cars had three piece ball or needle roller thrust races. Normally the thrust race was located in a recess in the upper flange of the lower kingpin bush and a tin cover, trapped between the race and the axle, fitted over the bush flange. Steel shims were fitted between the axle and the top bush so that there was zero clearance in order to stop the balls hammering dents in the races; which is why ball races are normally preloaded. The tin cover was not a tight fit so lot of grease was required to keep out the muck, hence the 1000 mile grease–up and check levels services that were still a requirement on some new vehicles well into the 1960’s.

John

Edited by Barney
Re-written to clarify information
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Incidentally, does anyone have experience of using molasses in water as a de-rusting agent?

 

It's been years since you asked this question, but I have been using it recently on the Ner-a-Car.

 

https://picasaweb.google.com/lh/photo/Dn4MvZsycmAR-2H80DSkLNMTjNZETYmyPJy0liipFm0?feat=directlink

 

The picture shows a number of parts as they came out of the tank after a wash and a scrub. They had been in the tank for about 3 weeks. The right-most part was in reasonable condition, and is cleaned to silver metal. The other parts were all rather pitted, and are shiny where scrubbed and darker in the pits. Some part have immediately rusted on exposure to air.

 

It's probably best to fish the parts out and wash them on a sunny warm day.

 

Anyway, it definitely works, and the black treacle solution seems like an easier thing to dispose of than a similar quantity of phosphoric acid.

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I have used molasses a lot and had good results with it. I use one part of molasses to 6 parts water and leave the rusty part submerged for 2 to 3 weeks, then water-blast the gunk off and leave it to dry in the sun. I have been surprised at how well it works and in my experience it has not immediately starting rusting again either, although that might vary with the type of steel. I am on a farm so storage and disposal are not a problem. Molasses is dirt cheap (30c/kg here) non-toxic, environmentally friendly and doesn't have the disadvantages of sandblasting (cost and warping) or electrolysis (explosive H2 gas). Just don't be in a hurry :-)

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We remembered today that we had another very poorly Thorny front axle tucked away in the “Stores Department” and we decided to dig it out to see if the stub axles and bearing surfaces were any better than the ones that we have just released.

 

The pictures will show you that the ends do look promising with clean shiny bearing surfaces and it would seem worthwhile to push the King Pins out to have a good look at them.

 

You will also notice that the main beam is very corroded and wasted away – and beyond redemption.

 

 

DSCN0298_zpse767965a.jpg

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DSCN0304_zpsf55c0f67.jpg

DSCN0302_zps1f63ed04.jpg

DSCN0300_zpsb172220d.jpg

 

 

Edited by Marmite!!
Formatting editted at Tony's request
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Regarding the king pin bush/thrust race I suspect that if you put your sample in the derusting solution a join will appear which shows that the bush is pressed into the race. I have seen an application like that elsewhere (but don't ask me to remember just where!). Any hammering of the pin against the bush will have peened the join line so it is not obvious. The metallurgical demands of each function are quite different so they must be two parts.

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Regarding the king pin bush/thrust race I suspect that if you put your sample in the derusting solution a join will appear which shows that the bush is pressed into the race. I have seen an application like that elsewhere (but don't ask me to remember just where!). Any hammering of the pin against the bush will have peened the join line so it is not obvious. The metallurgical demands of each function are quite different so they must be two parts.

 

I would tend to agree with this.

 

Just not the molasses, it would take too long ;)

 

trevor

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Your new axle out from the storage pile has a metal shield plate about the end of stub axle to deflect mud etc and give some protection to the bronze bush. Did the original axle have one of these deflection plates?

I've noticed from my own collection some axles have this metal plate, while other axles do not have them. Again a change in design over time.

Were there any other stamped numbers or letters about the king pin area that may help in placing these axles into a time frame of manufacture?

Doug

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Your new axle out from the storage pile has a metal shield plate about the end of stub axle to deflect mud etc and give some protection to the bronze bush

Some agricultural equipment had hard felt seals fitted in these deflectors; they didn’t stop the oil leaking out but they slowed it down somewhat.

Some engine manufacturers used hard felt seals on their timing covers, rear main bearings and gearbox input / output shafts right into the 1960’s.

John

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Your new axle out from the storage pile has a metal shield plate about the end of stub axle to deflect mud etc and give some protection to the bronze bush. Did the original axle have one of these deflection plates?

I've noticed from my own collection some axles have this metal plate, while other axles do not have them. Again a change in design over time.

Were there any other stamped numbers or letters about the king pin area that may help in placing these axles into a time frame of manufacture?

Doug

No - the first axle did not have such shields.

 

I have not been able to read any numbers on the new axle - yet -it needs a thorough cleaning to be able to get in there!

 

On the first axle, the number 186 is stamped on one side in the King Pin area - and on the other one it is stamped F2 although that could be KF2 or even XF2 and underneath that is "Leeds 6194"

 

Tony

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On the first axle, the number 186 is stamped on one side in the King Pin area - and on the other one it is stamped F2 although that could be KF2 or even XF2 and underneath that is "Leeds 6194"

 

Tony

 

'KF' is likely to be the 'Kirkstall Forge' of Leeds. They made axles for Dennis too!

 

Steve

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'KF' is likely to be the 'Kirkstall Forge' of Leeds. They made axles for Dennis too!

 

Steve

 

Thanks Steve for the name.

I've spent some time trying to piece together any link with the numbers and letters stamped on various Thornycroft front axles, about the king pin areas.

To date I have looked over 11 axles but have no significant pattern emerging.The KF appears on only two J models then in different forms being more stylized as a YK joined together.

Other axles have stamped a variety of letters and numbers. A, H, T, l, N are all found separately on different axles.

Could the other letters be also foundries?

I was assuming they were otherwise inspection stamps.

Doug

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'KF' is likely to be the 'Kirkstall Forge' of Leeds. They made axles for Dennis too!

 

Steve

i remember the Kirkstall forge when it was up and running.....

 

we used to walk past it...down onto the canal at newlaithes...then on to the canal basin where the barges used to deliver coal to the Kirkstall powerstation...

 

both the powerstation & Kirkstall forge are gone now....

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You will also notice that the main beam is very corroded and wasted away – and beyond redemption.

 

It smacks of desperation, but I am having decent results with my current restoration (not miliatary, not truck) filling in rust pits with TIG and grinding back.

 

(if anyone is interested in a off-topic restoration, http://bodgesoc.blogspot.co.uk/2014/04/1921-ner-car.html

I plan an update tonight. Err, this morning)

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It smacks of desperation, but I am having decent results with my current restoration (not miliatary, not truck) filling in rust pits with TIG and grinding back.

 

(if anyone is interested in a off-topic restoration, http://bodgesoc.blogspot.co.uk/2014/04/1921-ner-car.html

I plan an update tonight. Err, this morning)

 

*I was quite glad for the Self-Checkout lane in the supermarket when I was buying 12 tins of treacle and nothing else*

 

:-D

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It smacks of desperation, but I am having decent results with my current restoration (not miliatary, not truck) filling in rust pits with TIG and grinding back.

 

(if anyone is interested in a off-topic restoration, http://bodgesoc.blogspot.co.uk/2014/04/1921-ner-car.html

I plan an update tonight. Err, this morning)

what you using?

 

De-oxidised stainless rods?

 

weld cast lovely with the argon set will stainless...

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Steve and Tony have been in Devon getting the Dennis ready for the Brighton Run next Sunday. This has gone OK and they found some time to have a look at the Thorny front axle. Steve started by cleaning up the stub axles and then putting the micrometer on them. The left hand one is 0.025” out of round which we can live with. However, the right hand one goes from 0.040” to 0.090” out of round at the inner end which definitely caused them some concern.

 

DSCN0371_zpsa9578256.jpg

 

With the right machinery, the stub could be skimmed to straighten it up but this would need a 12” centre lathe which we don’t have. They therefore decided to have a look at the trailer converted axle to see if the stub on there could be used. On that axle they found the bearing surfaces to be excellent but unfortunately, neither stub had the steering arm which is part of the original forging so no joy although the axle did yield the cover for the thrust bearing.

 

DSCN0374_zps99e00423.jpg

 

They then proceeded to rescue the last front axle from the undergrowth. This was the one which came with the original set of parts from North Wales in 1989.

 

DSCN0376_zpsdf56f28e.jpg

 

Steve polished up the stubs and found that the LH one was very pitted and no better than the one we had previously removed.

 

DSCN0383_zps612f8009.jpg

However, the steering arm stub polished up well and was found to be no more than 0.005” out of round and to be parallel within 0.005” as well.

 

DSCN0382_zps3c149b20.jpg

 

This is ideal so the problem is solved. The next challenge is to remove it from the beam. They started this afternoon but, as usual, it will be a fight and battle will resume tomorrow.

DSCN0388_zps294a2ea2.jpg

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  • 5 weeks later...

Is it holiday time down in Devon? I am sure I am not the only HMVF reader lookling forward to the next installment? Now that the catalogue has been published for Michael Banfield's sale, I see that there are dozens of WW1 chassis just waiting to be collected for a rust up restoration.

 

 

Best wishes,

 

Barry.

 

http://www.bonhams.com/auctions/22201

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