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WW1 Thornycroft restoration

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1/16" seems about right I'd say. You'd need to be sure the axle end nut was pinned or locked so it wouldn't self-tighten though.

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1/16" seems about right I'd say. You'd need to be sure the axle end nut was pinned or locked so it wouldn't self-tighten though.

 

I think the place to start is that you always want some tiny float even in the worst case scenario.

So work out how far differential thermal expansion could make things go wrong at the melting point of brass, and you need no more than that.

 

I would guess we are talking about 50 thou.

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Two great nights of looking in, great progress, great thread, great guys, it's all just great, well done, and thank you for sharing.

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Based on experience of steamers which are all plain bearings you should be aiming for as little as possible end float.

 

When I did the 2nd shaft on the engine I had to machine the spacer off site and ended up with 10tho' which I was happy with. This is a similar diameter.

 

Bronze bearings get hot and nip on the diameter not the side faces.

 

I would have also thought that excessive end float on the wheels would be hard on the halfshaft splines.

 

Its a simple turning job to make spacers to sort. Steel or bronze spacers will be fine.

 

Personally Id do a dry run without the oil seals, then put them back in, using the nut to force whe wheel home. Felt seals soon compress and make their own clearance.

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Well done on the great progress! Gives an incentive to work on mine, but first will be the 1916 Leyland.

As for the rear axle movement, I can only find reference in my J manuals to latter use of roller bearings. ( revised 1926 edition) It states when at excess of .008 inch end play on the washer packing, then reface the washer to reduce the end play to .0025 to .003 inch.

Doug

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Thanks Chaps. I shall invest in some bronze and tighten it up a bit. It does feel a bit generous at the moment!

 

Today we wanted to get the engine properly fixed down. Dad did not cut the bolt holes in the engine mounting angles when he made them as he felt it would be easier to mark them out from the crank case itself. He is right in this but I really didn't fancy lifting the engine again. Still, I gritted my teeth and off we went. First job was to get the engine into line with the gearbox. To facilitate this, I made a pointer from steel strip to bolt to the gearbox input spider. This worked well and it was quite easy by adjusting the engine position with a jemmy to bring it all into line.

 

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Then we had to lift the engine and remove the first mounting angle. All went well but I hate working under suspended loads. You only get one chance to get it right!

 

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We put the holes in using the mill. As usual in this game, the mill was stretched to capacity, firstly by height in drilling a 1/2" hole and then in torque turning a 3/4" end mill to finish.

 

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This was done for both sides and then, much to our relief, the engine was lowered back down.

 

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We had four bolts in stock which were trimmed to length and had split pin holes drilled before fitting and tightening up. They went through all of the holes without adjustment!

 

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The engine is now installed!

 

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Gearbox to be finally fitted tomorrow along with some other bits and pieces which can now go on. One thing is bugging us though. Some time ago, Father repaired the rear wheel tyre size plates and I made up some brass screws to secure them and these can now be fitted. However, we cannot find them! Dad has been searching all day and it is causing serious annoyance!

 

More tomorrow.

 

Steve

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Back to it for a final stint before the return to reality!

 

I found an odd box this morning within which were the missing plates. Father wasted no time in attaching them!

 

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I then fitted the front wheel greasers,

 

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the gearbox breather, rescued from a chassis on a farm at Great Missenden twenty years ago,

 

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and then re-fitted the engine oil pipes which had been removed for safety during the lift.

 

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Thoughts turned to the rear axle and differential so kindly given to us by Mike in New Zealand. The differential is the last major component needed in the chassis.

 

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We pulled it out and then set about lifting the differential from the casing. As you can see, it is in wonderful condition. Even the splines look like new.

 

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We pulled it out and then set about lifting the differential from the casing. As you can see, it is in wonderful condition. Even the splines look like new.

 

 

 

I can imagine the look on your faces when seeing that gear ........ absolute magic, looks like you are starting the year off well. Great stuff!

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Whilst playing with this axle, we realised that we had not removed the wheel thrust washers. On inspection, we realised that they were much thicker than those already on the chassis so we may well have a solution to our end-float issue.

 

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We fitted the starting handle and I gave the engine a good swing. Very satisfying!

 

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The handle appears to protrude forwards a very long way. This is odd as the shaft is an original Thornycroft component. At least it reduces the chances of my smashing my teeth on the radiator protector bar!

 

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Next was the sump level tap,

 

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Followed by the priming cocks.

 

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Father dug out the best original fan.

 

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After a clean-up, this was fitted too. The engine is beginning to look rather pretty!

 

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The gear change shaft support was installed.

 

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Then I started looking at the steering box.

 

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I dropped it in but it fouls an engine mounting bolt and the holes don't line up!

 

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I think we should get away with dressing a corner from the nut but that is a job for another day.

 

That is the end of our progress for this Christmas. I am back to finishing my motor house for the Dennis. Once that is done, I can make some more patterns for the Thorny. Must keep the momentum up. Only two years and five months left to go and it is going to be tight!

 

Happy New Year everyone!

 

Steve :D

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Happy New Year to you all. Great progress and thank you so very much for a wonderful and exciting thread. I greatly admire your dedication and your skills. Can't wait to watch your further progress in 2016.

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You have certainly made good use of the Christmas break - what a difference ! Well done the Goslings !

 

It may well be that Thornycroft had other ideas but I was 'brought up' to always put bolts in from the top so that if the nut were to come undone, at least the bolt would probably remain. It is also marginally easier as the bolt doesn't need holding up while you put the nut on. Obviously it is easier to split pin it with the nut at the top and the nut is then unlikely to undo by itself but I still find nuts on top just feels wrong. What does everyone else think ?

 

This post was prompted by the thought that the steering box would have been nearer to fitting if the engine mounting bolt had been fitted from the top. Then I wondered if 1/4" packing plates under the feet of the steering box bracket would solve the problem without any noticable change to anything else and would be virtually undetectable when the vehicle is complete.

 

Happy new year to everyone,

 

David

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Hi David.

 

Yes, putting the bolt in from the top would probably give us enough clearance. However, the engine mount is a piece of angle and the position of the hole is such that there is insufficient room to turn the hex underneath. I think that just dressing a little from the corner of the nut will do the trick. Failing that, packing the box up would also sort it.

 

Just for interest, here is a picture of the Carlton Colville engine mount.

 

A For Posting.jpg

 

Cheers!

 

Steve

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My thought was also to lift the steering box, though I would go for turned collars which would facilitate some self alignment of the bolt holes. Of course, the original position of the motor has been lost so perhaps it should have been further back?

Edited by mammoth

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You can talk! They will be calling you 'Dynamo Hawkins' very shortly!

 

Steve :D

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Thanks Chaps. I shall invest in some bronze and tighten it up a bit. It does feel a bit generous at the moment!

 

Today we wanted to get the engine properly fixed down. Dad did not cut the bolt holes in the engine mounting angles when he made them as he felt it would be easier to mark them out from the crank case itself. He is right in this but I really didn't fancy lifting the engine again. Still, I gritted my teeth and off we went. First job was to get the engine into line with the gearbox. To facilitate this, I made a pointer from steel strip to bolt to the gearbox input spider. This worked well and it was quite easy by adjusting the engine position with a jemmy to bring it all into line.

 

[ATTACH=CONFIG]111362[/ATTACH]

 

[ATTACH=CONFIG]111363[/ATTACH]

 

Then we had to lift the engine and remove the first mounting angle. All went well but I hate working under suspended loads. You only get one chance to get it right!

 

[ATTACH=CONFIG]111364[/ATTACH]

 

We put the holes in using the mill. As usual in this game, the mill was stretched to capacity, firstly by height in drilling a 1/2" hole and then in torque turning a 3/4" end mill to finish.

 

[ATTACH=CONFIG]111365[/ATTACH]

 

This was done for both sides and then, much to our relief, the engine was lowered back down.

 

[ATTACH=CONFIG]111366[/ATTACH]

 

We had four bolts in stock which were trimmed to length and had split pin holes drilled before fitting and tightening up. They went through all of the holes without adjustment!

 

[ATTACH=CONFIG]111367[/ATTACH]

 

The engine is now installed!

 

[ATTACH=CONFIG]111368[/ATTACH]

 

Gearbox to be finally fitted tomorrow along with some other bits and pieces which can now go on. One thing is bugging us though. Some time ago, Father repaired the rear wheel tyre size plates and I made up some brass screws to secure them and these can now be fitted. However, we cannot find them! Dad has been searching all day and it is causing serious annoyance!

 

More tomorrow.

 

Steve

 

this is where a MAG drill/rotabroach would have been better Steve

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Wonderful to see the progress . . . I'm sure you'll have "the monster" up and running soon. The pictures and commentary are a lesson in itself! Thanks for sharing . . .

 

Bosun Al

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With the engine and gearbox now firmly located within the chassis, we decided that we would like to give the lorry a “face” in the form of attaching a Radiator! We do not have a Radiator and are faced with making one.

 

The construction of a Radiator has been in our planning over the years and when talking to our friends at the Hampshire County Museum Service and at Carlton Colville some time ago we found that they also wanted new Radiators for their “J’s” – as in the case of Carlton Colville, the original one on their “Thorny” had become badly corroded and was leaking – really beyond repair. So the three of us jointly commissioned patterns to be made for the four cast aluminium, parts of the Radiator – top and bottom tanks and the two side supports, sharing the costs. The three sets were all cast at the same time. Machining the bolting faces of these four castings was beyond the capabilities of our modestly sized machinery and they were faced off for us at the same time as the other castings were done. So we have those four castings in stock – ready to go!

 

We shall make the core ourselves – but this will be an expensive job. We shall need about 20,000 Gills to be thread on the tubes – these are available commercially and cost about £30 per thousand – you work out the cost of those! On top of those, there will be brass for the top and bottom of the core and also the copper tubes. So the total cost of the core is certainly going to be in excess of a thousand pounds!

 

Anyhow, to start the ball rolling, Steve has completed sketches of the Radiator Filler Neck and the Screw Top for the Axminster Division to get cracking on. The dimensions and shapes of these were taken from original Thorny J fittings some time ago.

 

We have always kept our eyes open for Bronze Bar Ends at Autojumbles or Traction Engine Rally Sales Stalls and fortuitously find now that we have enough of these in the right size in stock to make these bits without having to buy more!

 

The bolting flange was parted off from a piece of 3” diameter, hollow bronze bar and then faced off and bored out in the Myford Lathe. It has purposely been left over thick, as part of the final machining will take it down to its final thickness of just 3/16 of an inch.

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The sketch of the bolting flange was transferred in scale to a piece of paper and laid across the top of the Radiator Top Tank, just to check it – but it seemed to be a little narrow against the machined face of the Radiator so the dimension across has been slightly enlarged to take advantage of the full width of the bolting surface. Both versions can be seen in the sketch

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The actual neck of the Filler was another off cut of hollow bronze bar, marginally over 2 1/2” in diameter and about 1/2” over the final required length. That again was held in the Myford to be bored out and for the first outside diameter to be machined. The bar was then reversed in the chuck for the final outside diameter to be machined prior to screw cutting. The embryo neck was, perhaps quite unorthodoxly supported, for the final cuts to be taken and for screw cutting by the taper on the drill chuck.

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The Neck was successfully screw cut to take the cap and the surplus on that threaded end was machined off so that the neck was correct in length and then the end was tapered at 45 degrees.

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The Bolting Flange shape then had to be finally marked out on the 3” bronze disc.

 

A “dummy” was machined up to fit firmly into the big hole in the embryo flange with a clear centre in that which could be used for the centre for dividers to mark out the final required curves and for the holes to accommodate the bolting studs. After these had been scribed, it was easy to join up those circles to obtain the final shape of the flange.

 

The Neck was dropped into embryo flange to see how it looked!

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The final shape of the bolting flange was obtained by cutting off the surplus and filing the disc to shape. The holes for the bolting studs were drilled to take filing buttons and a steel disc was machined to an identical diameter to the larger curves on the out side and attached to the embryo as something to file around.

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And now moving on to the Cap! Again fortuitously, we had a bar end of 3” bronze in stock and a small length of this was cut off with the Band saw.

 

The first job to do on this was to cut the “hex”. The outside diameter was machined down to just slightly in excess of the finished o/d of the cap. There is no Rotary Table at the Axminster Division so the “hex” was machined using the rotary machine vice on the Mill. Opposite cuts were taken first of all – the machine vice was rotated through 60 degrees to take two more opposite cuts and then finally, it was rotated a further 60 degrees to take the final two opposite cuts.

 

It was essential to measure as the cutting progressed – the drawing specified 2.048” A/F – the bar was measured accurately in diameter at commencement of the cutting and with simple arithmetic, it was easy to work out when to stop cutting each time!

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