restoration CVR(T) 65247 invades the USA

[teletech]

Well, it was a lot more work and money than I bargained for it's true. I think I needed a break to recover from the import and realization of what was before me. I can't give up, partly because wandering through my shop and noticing tracked armor still makes me smile and partly because it seems like every horizontal surface is covered in CVR(T) bits!

 

I've been avoiding Facebook but I suppose I'll have to have a go at some point, I would love more history on this vehicle.

 

Thanks for the kind words. I'd love to make it to Aquino but we are a man down at work so I have to be here to run the telescope that weekend. Next year for sure, say hi to Al and the guys for me!

 

have fun!

P_

 

Great to see you are still making progress with your vehicle, I was worried at one point that it might have become all too much for you, all credit to you.

 

There is a CVRT facebook group and some of the Belgians have been on there and some people have found in service vehicle pictures through it.

 

Hope to see you at Aquino

 

Robin

[justinb]

fantastic job you're doing there .

I feel your pain having taken on an ex Belgian scimitar myself .

will you be able to get it street legal over there?

regards

justin

[teletech]

Thanks for the kind words. How long did it take to get yours going?

Any chance yours came from Terry as well?

 

In California, I can run it on the roads withing 1/4 mile of my shop with no paperwork or anywhere on temporary permits (18USD each) so not ideal but as a percentage of the total cost not too bad.

 

 

fantastic job you're doing there .

I feel your pain having taken on an ex Belgian scimitar myself .

will you be able to get it street legal over there?

regards

justin

[justinb]

[i think it might have come from terry originally but I bought from a third party .

I think it took me around a year to get it mobile and road legal ,I've still got loads of finishing touches to do !

QUOTE=teletech;468669]Thanks for the kind words. How long did it take to get yours going?

Any chance yours came from Terry as well?

 

In California, I can run it on the roads withing 1/4 mile of my shop with no paperwork or anywhere on temporary permits (18USD each) so not ideal but as a percentage of the total cost not too bad.

[justinb]

I think it may have come from terry brooks originally but I bought it from a third party.

it took me approx. a year to get it mobile and road legal but iv'e still got a lot of finishing touches to do,mainly in the turret

 

QUOTE=teletech;468669]Thanks for the kind words. How long did it take to get yours going?

Any chance yours came from Terry as well?

 

In California, I can run it on the roads withing 1/4 mile of my shop with no paperwork or anywhere on temporary permits (18USD each) so not ideal but as a percentage of the total cost not too bad.

[teletech]

I feel like such an underachiever, a year for me and mine isn't even quite fully disassembled.

Did you ever find a source for a traverse gearbox?

 

I think it may have come from terry brooks originally but I bought it from a third party.

it took me approx. a year to get it mobile and road legal but iv'e still got a lot of finishing touches to do,mainly in the turret

 

QUOTE=teletech;468669]Thanks for the kind words. How long did it take to get yours going?

Any chance yours came from Terry as well?

 

In California, I can run it on the roads withing 1/4 mile of my shop with no paperwork or anywhere on temporary permits (18USD each) so not ideal but as a percentage of the total cost not too bad.

[teletech]

I haven't forgotten about this though having a running Ferret might be a distraction. 🙂

After pricing having the vehicle moved I bought a ramp-truck to be able to transport my CVR(T) and Ferret at a whim.  I got the hull up on the truck and there it sat for the winter while I tried to find a sandblaster who wanted to take on the work of stripping the hull at a price I could afford.  Finally the stars aligned and the hull is now blasted.  I'll have to clean up where the two remaining roadwheel stations were left but otherwise I'm ready to start painting and then reassembly!  The fellow doing the work did miss a few small spots but I'm far less upset by his omissions than pleased by the areas I thought it unlikely he'd be able to manage.  For one thing the inside of the cavity for the fuel bladder is surprisingly decent on all six sides.  I also asked him to leave the reg number so I could accurately reproduce it's shape, size, and location and he also left the UN mission markings as well, which suits me fine.  I can't quite see my way to painting the vehicle UN white but I'll make a white panel in the area of the markings to commemorate it's service history.

OK, now it's time to break out that surplus PPG aluminum primer I bought from Boeing during the shutdown and have at it.

 

Edited May 19, 2021 by teletech

[teletech]

Some primer applied, still need to touch up a couple areas and get a second coat in a few more, but it's mostly one color and just about ready for paint.

So, getting ready for the next bit, pivot brackets. I'm curious to know if it's recommended to replace the seals or if they look fine to just re-use them?  The larger inboard seal 2530-99-835-5787 look like they should hold up well and the small outboard seal that's basically an X-cross section o-ring 5330-99-942-9983 looks both less robust and also cheaper.  Is there an easy industry-standard replacement perhaps? 

I notice the XMOD has a listing for a 5331-99-942-9983 which has the same ID but a standard round cross section: https://www.thexmod.com/item_detail.asp?id=7234&t=ORing_6170_Deg_2.6_IN_ID_SSML717_100334

After that I start in on torsion bars.  Mine are utterly disgusting.  Do I just wash them off and hope for the best or should I remove all the wrap tape and then re-wrap?  If I'm removing the tape should I then sandblast, shot-peen, or treat the bars in some other manner to help them last?  Some sort of paint in addition to or instead of the tape?

Edited May 19, 2021 by teletech

[teletech]

Over a year since the last batch of updates and I haven't much to show on this vehicle for the time:  A second coat of primer and more recently I got the axle pivots sanblasted, cleaned, and primed (PPG DPLF epoxy).  Then just yesterday I got them bolted on.  I used CA 1000 Mastinox non-chromate corrosion inhibitive jointing compound from PPG Aerospace (Boeing surplus) as an available replacement for the chromate-based stuff I'd have rather used.  Careful squeegee on the mating surface of the pivot, then in the bore and all the tapped holes as well as the male threads of the bolts (as pictured) used a full 6oz tube of the stuff.  I have a second tube, most of which I expect to use getting the turret-ring bedded-down.  Hopefully since the FAA approves of it for dissimilar metals joining, it works at least reasonably well.   Today I went over the installed fasteners with the same epoxy primer since there was no plating left on the heads and I also wanted the topcoat to have something to stick to.

I didn't find a torque-spec for those bolts in any of my many manuals, so went with 60Ft/Lb based on what I could find in generic torque data charts for bolts in Al.

What were these painted with originally?  I could use CARC if that was the right thing to do, but am also fine using something less annoying to buy and spray.  I know Marcus Glenn and others have paint, but international shipping of hazmat being what it is, I'd much rather use PPG, S-W, or something else I can get stateside.

OK, now it's time to go refinish a bunch of torsion bars.  I'm not sure if I should refrain from media-blasting them, but once I have the tape off I'll know how well that protected them from rust-pitting and such.

 

[teletech]

Finally separated the trailing-arms from the torsion rods and drained the bearings. Some of my rods are rustier than I'd like and I don't know the best treatment (short of replacement but the spares I bought didn't make it to me, so that will have to wait.) to mitigate the surface damage from rust.  Almost half of the roadwheel-axle assemblies still had an amount of grease I list as "willing to drive a medium distance", one had the merest coating of oil, and one... well it looked like this:

[teletech]

I've been making covers so I can sandblast and paint the hubs and pivot arms without grit getting into the bearing areas.  In doing so, I've had to really realize what deplorable shape my pivot-arm bearings (bushings) are in!

They need pretty much wholesale replacement.  So, where does one find 20 new bearings?  They are apparently copper-covered steel, so just making some isn't likely to happen.  I was thinking that for the few miles a year I was likely to drive, perhaps I could make new ones out of brass, bronze, oilite, or even one of the fancy UHMW plastics.  Have people had much experience with the act of replacing these or making new ones?

Edited March 11, 2023 by teletech
typo

[teletech]

Inspecting the pivot-arm bearings made clear they were going to need wholesale replacement.  Most are heavily worn and many are worn all the way through the brass/copper layer.  In more than one case, I found .030" of wear and that wasn't to the bottom of the scratches!:

 

 

 

Edited March 19, 2023 by teletech

[teletech]

I'd spoken to a mechanical engineer about alternatives and the early math did suggest that oilite bearings should work fine.  I found one that had the correct ID and length, but was too large in OD.  I'd have to make a little fixture for the lathe and turn them down, but that's an easy job on a self-lubricating material!  I went shopping around and found some for about half the price of my first source, so was waiting for the final math when I found what seems very much like the perfect item for the job.  It's got a layer of PTFE on top of the layer of bronze, but that should work just fine.  I do wonder how thick the Bronze layer is, but I guess I'll order one and find out.

https://asbbearings.com/collections/3-id-steel-backed-ptfe-lined-inch-sleeves/products/zu-48zu32

Now I need to decide on the O-ring to seal the outside-end of the pivot-arm shaft.  originally I think they may have been square or X in cross-section, then changed to round.  I'm thinking the double X profile might be the best and wondering what material and hardness to use for best lift and the least leakage?

Edited March 19, 2023 by teletech

[David Herbert]

In respect of the seals, it is common practice in tracked armored vehicles for the seals in the suspension and wheel hubs to be primarily designed to keep dirt and water out. Keeping lubricant in is secondary as regular maintenance can usually be ensured by standing orders.

David

[teletech]

4 minutes ago, David Herbert said:

In respect of the seals, it is common practice in tracked armored vehicles for the seals in the suspension and wheel hubs to be primarily designed to keep dirt and water out. Keeping lubricant in is secondary as regular maintenance can usually be ensured by standing orders.

David

Very good point.  In this case they failed on both counts, but I suspect poor service was the root cause there.  In my case, I don't plan to run it often but would like my floor to stay at least mostly clean, so I'm willing to optimize for quality of seal vs. longevity (within limits of course).

[hauptmanngurque]

If you are looking for sealing, I think it is important to change the rear pivot axle seals, or at least their rubbers (personally some of mine are mounted wrong and with deformed rubbers) but these are difficult to find. The O-ring that sits in the pivot axle channel is a standard size (BS334) in X-ring or quad-ring version (in mine some of them were normal round o-rings) of course it is essential to change the sleeve bushings for new ones. any excess play in the pivot axle will have an effect on the lack of tightness of the assembly.  By the way, the 3-3/16 sleeve bushings have a slightly smaller external diameter than the original ones.

[teletech]

19 minutes ago, hauptmanngurque said:

If you are looking for sealing, I think it is important to change the rear pivot axle seals, or at least their rubbers (personally some of mine are mounted wrong and with deformed rubbers) but these are difficult to find. The O-ring that sits in the pivot axle channel is a standard size (BS334) in X-ring or quad-ring version (in mine some of them were normal round o-rings) of course it is essential to change the sleeve bushings for new ones. any excess play in the pivot axle will have an effect on the lack of tightness of the assembly.  By the way, the 3-3/16 sleeve bushings have a slightly smaller external diameter than the original ones.

I plan on changing the rubbers on the rear seals and am very interested in knowing if anyone has found a suitable replacement or if I'm going to have to make new ones.

I read in the manual that they used X-ring originally but switched to standard o-ring for the ones on the end of the shaft.

Good to know about the 3-3/16" issue.  I guess if it's too small then I'm back to using oilite bearings and turning them to size as a replacement.  Double the money, more time, and I'll want my mechanical engineer to do more math, but that's cheap compared to not getting it right!

[robin33ba07]

hello Teletech is this what you are looking for ???  https://www.thexmod.com/item_detail.asp?id=449&t=Seal_Pivot_Axle_AS38121_FV717522

2530-99-835-5787  ?  regards Robin

[teletech]

On 3/21/2023 at 9:43 AM, robin33ba07 said:

hello Teletech is this what you are looking for ???  https://www.thexmod.com/item_detail.asp?id=449&t=Seal_Pivot_Axle_AS38121_FV717522

2530-99-835-5787  ?  regards Robin

Not sure, but they are sold out in any case.  I've had an offer of one so I can at least use that to determine the hardness and as a pattern to make new rubber, also to inspect the surface finish on the metal.  I need to inspect them, but so far I don't have a reason to believe the steel on my current seals isn't usable or at least salvageable with some surface-grinder work.

[teletech]

I made the sealing-covers before realizing I need all new pivot-arm bearings, so it made sense to sandblast and prime the arm before doing the bearing press.  Slight over-restoration in hitting the casting flash with a belt sander to make for a slightly easier to clean finished product.

 

 

[teletech]

Today I finally pressed out my first set of the pivot arm bearings.  They wouldn't budge with my 2-ton manual press, but came out easily with my 8-ton hydraulic unit.

I sectioned one of the removed bearings and looked at it under a microscope.  It looks like about .5MM of brass/copper on a steel shell.  The back of the shell is lightly plated as well.

On 3/20/2023 at 2:53 PM, hauptmanngurque said:

 By the way, the 3-3/16 sleeve bushings have a slightly smaller external diameter than the original ones.

From this warning, I was fully prepared for the new steel bearing to be too loose in the bore, but pressing it in, it needed a very reasonable level of force to install, so perhaps the ones hauptmanngurque found were different from the ones I used or else my pivot arms were made with slightly different tooling.  I used the 2" long 3" from https://asbbearings.com/collections/3-id-steel-backed-ptfe-lined-inch-sleeves

I'm still not at all sure I wouldn't prefer to use oilite bearings, especially for refit, since they are sintered bronze throughout and so won't tear up the pivot brackets like the steel ones do as soon as you cut through the PTFE and bronze layers.  I suspect they are much more tolerant of marginal lubrication as well and for the short runs most of us do would likely be fine without free liquid in the reservoir.

As for the ones I took out, this one had over .030" of wear in the worst areas, so 1.5X the depth of the wear layer!

 

[hauptmanngurque]

I am glad to know that you are mounting the sleve bearings and that these 3 inch ones fit correctly. In principle there should be a difference of a few tenths with the originals. I am in your same situation and I am waiting for a complete set of them to proceed with the change.

[teletech]

8 minutes ago, hauptmanngurque said:

I am glad to know that you are mounting the sleve bearings and that these 3 inch ones fit correctly. In principle there should be a difference of a few tenths with the originals. I am in your same situation and I am waiting for a complete set of them to proceed with the change.

Are you using lined steel, or something else?

At the moment, I'm planning to do a mix of 2" lined steel, 2" sintered bronze, and also try a couple of each at the full 5".  Someday I'll have it running and will be able to report on what works the best.

[hauptmanngurque]

14 minutes ago, teletech said:

Are you using lined steel, or something else?

At the moment, I'm planning to do a mix of 2" lined steel, 2" sintered bronze, and also try a couple of each at the full 5".  Someday I'll have it running and will be able to report on what works the best.

bronze coated steel.
For civilian life, I sense that sintered bronze can be good, at least it won't cause so much wear on the pivot axis.
of course in the Mod. It does not appear that they were given adequate maintenance, certainly not in their last few years in service.

[teletech]

I received the rest of my bushings, about half of the steel-bronze-PTFE and half sintered bronze.  Mostly 2" like the originals, but I picked up a couple 5" based on the wear pattern I was seeing on the axle pivots.  I'll bore a hole in them where you add oil.  I'm not sure full-length steel would have been good when everything was  new and tight because it would have reduced the oil reservoir, but now there is enough wear on the pivots I feel good about having enough volume in there.

The steel ones just push in, for the sintered bronze, I had to turn them to the correct OD.  I made a simple mandrel of a body of barely-touched aluminum, a stop collar, and end-cap to hold the bits on the arbor.  As before,  anyone wanting the tooling is welcome to it for the cost of postage and the proviso that you offer it up similarly when you are done with it.