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restoration of a valentine MK5 tank started


monty2

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The Bush material that is used is Nyloil, which is an oil impregnated plastic. This material is designed for such applications, and we also use it in stone crushing plants , etc. The first pic shows the Nyloil in basic form next to the needle roller bearing that it is going to replace, and then next to those is the original fibre bush that was made back then to replace the needle roller. The action of the suspension unit in this area is only one of rocking up and down, and very limited in that movement.

Next couple of pics show a crude little jig I made to hold the port windows of the Turret , to push the pins out, that were stuck in there, through sitting. When the pins were polished up, you could push them back in the housing by hand, and they were a really neat fit. Cheers from The Tank Factory.

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Today we bolted the Turret ring in place. It rotates very smooth, with no tight spots. It is held to the ring by 30 x 3/4" BSF bolts that are hex head with counter sunk head as well. There are 26 horizontal and 4 vertical underneath where the gun cradle goes. These 4 have their heads machined down so as to not interfere with any gun cradle movements. We also fitted the refurbished Revolver Port holes as well, all nicely greased up for action. Cheers from The Tank Factory.

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Also , in a separate bay in the wkshop, work has commenced on the Turret electricals. The Turret electric rotation motor has been stripped and new bearings fitted, also the hand controller for operating the Turret left and right is being looked into. Cheers from The Tank Factory.

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A few more pieces to the puzzle have been completed. The Turret electric hand controller, and the Turret electric rotation motor have all been refurbished. They are set up on the test control board, to make sure these will work properly before installation. Also we are disassembling the shock absorbers for refurbishing. There are 4 per Tank, one incorporated in each suspension unit assembly. Most of these are usually seized because mud and water have got into the lower tube housing, through the drain hole and have corroded the piston rod near the seals. They are very tricky to disassemble as every part has a spring retaining clip or are pegged with a grub screw. I had to make a hydraulic adapter plug, so we could hydraulically force the seals out the end so that we could get access to the piston end stop, which is 4" inside the tube. Once this end stop is removed the whole rod and piston will come out of the tube. Cheers form The Tank Factory.

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  • 2 weeks later...

After eating plenty of plum duff, it is now time to get the production line started again. Work continues on the disassembly of the hydraulic spring dampners. I have set up a molasses tank to naturally strip any rust and to clean up the inside of the tubes. I still have a couple to go as the rods are corroded and I want to make sure the inside oil jet holes are clear before I pressurize the cylinder to force the seals out. The seals will be replaced with new ones, which hopefully should be able to be worked out as the inner piston rod is standard 1" hard chrome shaft, but I still have to size the inner diameter of the main tube, so as to obtain the correct rubber seals. The seals were originally natural rubber, which uses mineral oil as the liquid in the cylinder. As we have a few cylinders to choose from , we may only have to replace a couple of the inner piston rods, due to the corrosion. Later this week I will update the suspensions, as these have all now been blasted and painted. Also checked the other day and the Crankshaft has all been ground to .010" on mains and big ends, and has been fitted to block.

We are currently waiting on piston gudeon pins to turn up from the States, as when the piston boxes were opened, these were missing, as well as a few shims to deck the liners to the proper height, a new complete water pump also turned up recently as well , so work still continues in this area. Cheers from The Tank Factory.

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The seals were unlikely to be natural rubber if mineral oil was the original filling, the two are not compatible. Cromwell etc. use a composite seal to allow the use of mineral oil.

 

Hi Andrew,

I note in the manual for the Valentine III that Newton Bennett shock absorbers were fitted. Having had dealing with these types on an armoured car, I would be doubtful if a mineral oil was used, and as Adrian points out, you should not use a mineral oil with natural rubber seals.

 

Fluid, Hydraulic Brake, No.3 was specified for the Newton Bennett shocks on the Humber armoured car and this was a vegetable type brake fluid. I believe that castor oil could have been one of its ingredients. After 60-70 years, it turns into a treacle type substance, I can tell you from experience. A replacement to day would be a normal DOT4 brake fluid.

 

Unfortunately my Valentine III manual does not show the fluid spec. for the shocks. Do you know what was specified as a fluid?

 

regards, Richard

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Hi guys, I knew I would get picked up on this! When I wrote it I was going by memory. I stand corrected.

The Valentine uses a Newton VT.II shock absorber, this is an upgrade from the VT.I., ( which used M80 ). The VT.II is now " filled and serviced with Fluid, Hydraulic Brake, No.3, other types are filled and serviced with M.80, as before. The change of fluid is made necessary by the fact that natural rubber glands are now fitted to series VT.II" . This is quoted from the Newton Shock Absorbers For "A" Vehicles, service instruction book 1941. Cheers Andrew.

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The following pictures show a nearly complete layout of the components that go into making the suspension station, which there are 4 per Tank, 2 x left hand and 2 x right hand units. Missing from the pic is a couple of dust covers for the double bogie unit and the main shock absorber shaft that are getting worked on at the moment. All units now painted in DBG Flat.

The road wheels are to be worked on in the next week or two. I am currently making the tooling for pressing the tyres off the rims, as there are a few to do, and we have a specialist forklift guy that has about a 200 ton ram mounted on the back of his truck. He just backs into the workshop and splits the rims apart, " hopefully " without too much trouble . We use him for doing our M3 Stuart tank wheels, but these are more simple in construction , where as the Valentine wheels you have to undo about a dozen or so 7/16" bolts, and once apart you will end up with 2 x rims , the inner hub , and the rubber tyre wheel that is vulcanized to it's steel rim band. Cheers from The Tank Factory.

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This week , the story continues on the shock absorber parts. The first 2 pic's show the new piston rods that I have spent the last couple of days making. The technical side of it , ones end takes a 3/4" BSF castle nut , this eventually bolts to the tube housing on the shock, the other end is 1" BSF, and the piston that travels inside the cylinder goes at this end. Inside the 1" hard chrome shaft is a stepped hole that takes the oil bypass valve and spring, and then an end plug is screwed in when all assembled. This thread is 5/8" x 20 TPI NF. The length of the total rod is 486mm. I am just awaiting the seal packs for the end of the cylinder and we can start assembling them soon. The main tubes are still brewing up in the Molassis at the moment, to get rid of any corrosion. The next 3 pics are of the wheel hub flange assembly, these were all stripped/blasted and painted and new seals installed. These seals run on the dust excluder tin cover that are in behind the wheels. These surfaces will be polished up and refurbed as well. This week has also seen a large number of wheels having all their bolts removed for getting ready to push the hubs apart, hopefully next week I can report on how my jigs and pressing tools have worked! Cheers from The Tank Factory.

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Todays exercise we pushed the tyres and rims off quite a few wheels. We are using a very handy 175 ton press mounted on the back end of a truck. We had already removed the 12 x 7/16" bolts that go all the way through the rims and hub. Some of the tougher ones were needing up to 40 tons of pressure, but this is only due to rust and old age. When everything is new, you can split the rims in the field with 4 bolts x 3/8" x 2" BSF long fully threaded, and these screw into threaded holes and push the rim from the face of the hub, and then you just bang the other side out. The rims have a slight taper so once started they do get easier to prise off. Cheers from The Tank Factory.

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Pictures show the pile of rims / hubs and medium size tyres ready for blasting and painting. There are 8 medium size wheels , with hubs, 16 x rims and 96 bolts and washers and nuts. The larger diameter wheels of which there are 6, and their associated rims and hubs, and 72 bolts! Cheers from The Tank Factory.

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the saddles that hold the recoil pistons and base of the gun, are they Brass or just painted that color?

 

I'm amazed at how complicated thing is. You always hear about the German armor being so complex, difficult to manufacture and maintain, etc. Do you feel the British vehicles are on par in that regard?

 

I remember reading a US army evaluation of a British cruiser vs. a Sherman, went something like the Sherman need major maintenance every 250 hours of field duty, the cruiser every 100 to 125?

This week , the story continues on the shock absorber parts. The first 2 pic's show the new piston rods that I have spent the last couple of days making. The technical side of it , ones end takes a 3/4" BSF castle nut , this eventually bolts to the tube housing on the shock, the other end is 1" BSF, and the piston that travels inside the cylinder goes at this end. Inside the 1" hard chrome shaft is a stepped hole that takes the oil bypass valve and spring, and then an end plug is screwed in when all assembled. This thread is 5/8" x 20 TPI NF. The length of the total rod is 486mm.
beautiful looking work

were you able to Lathe turn these with a live center and steady rest follower or did you centerless grind ?

Edited by draganm
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The whole gun cradle is a bronze casting - more resistant to fatigue cracking than the steels of the day and steel casting capacity was in very high demand vs. bronze.

 

My feeling is that German tanks were very sophisticated - sometimes too much: British tanks were just complicated !

 

The hard chrome plated rod is supplied finished ground for repairing hydraulic rams in inch and metric sizes and you just machine the ends as required. They doo look good though :thumbsup:.

 

David

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David is 100% correct with his remarks, the only thing we have done on the Bronze casting is to apply a clear Laquor, to hold it's sheen. When larger shafts are chromed more than , I think about 5 thou , they need to be centreless ground for trueness , and normally industrial coatings for wearing end up at about 10 thou at least. The following pics show the manlet nose cone and the 60mm inner shield being mated together, Cheers from The Tank Factory.

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I married the mantle to the 2pdr the other day. There are 6 x 1/2" BSF bolts that secure the bronze recoil housing to the nose cone, these are a snug fit. Then it was onto fitting this whole unit into the Turret. First I lowered the Turret stand over the gun and then the Turret was put back on the stand and then the gun was raised up to height with the strop through the roof hatch hole. I had my other gantry crane pulling the barrel through the Turret at the same time. Even with all this gear, it still took the best part of a day, as it is pretty hot over here at the moment ( 30C ).The 4th & 5th pic's show the gun depression stop being refurbished, and reassembled. This important little unit stops you blowing the back corner of your Tank off when you are in combat! The next pic shows the gun travel lock ready for installation, and the final pic shows all these bits installed at the business end of the Turret. Cheers from The Tank Factory.

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