GMC 353 - matching wood top bow to metal elbow

The 353, circa 1944 build, arrived without a complete set of elbows or bows... just one usable bow and a couple of usable elbows. GMC 353 spares on web-sites, for example:-

* http://jeep-dodge-gmc.com'>http://jeep-dodge-gmc.com'>http://jeep-dodge-gmc.com ;

* http://www.jeepest.com/ ;

* http://www.lwdparts.com .

all show elbows of similar style even though different "part numbers", none of those part numbers are noted in the illustrated parts list published July 1942. Wood bows are shown on http://jeep-dodge-gmc.com and those are probably not of original supply. So a set of wood bows and a set of elbows have been purchased... and the elbows fitted to the side strakes, as here.

The wood bows do not fit the elbows which have been fitted to the GMC, the bows are (a) too short and (b) need a tighter curve to align with the elbows. The wood bows which have been purchased from Jeep / Dodge / GMC are of similar length and curve to the one usable bow which came with the vehicle. The NOS elbows which have been purchased have a tighter bend than the elbows which came with the vehicle.

The following photos may help to understand the situation, the old elbows are in dirty green paint whilst the NOS elbows are in red primer (applied by me):-

this photo shows the replacement bow with the original elbows... and this set up does fit the strakes of the cargo bed.

this photo shows the replacement bow with the NOS elbows... this does not fit onto the strakes of the cargo bed primarily because the ends of the elbows are not parallel.

this photo shows the NOS elbow (red) in front of the original elbow (dirty green).

My guess is that the replacement bows are suitable for the 353 whilst the NOS elbows are not for this vehicle... and that I need to locate some elbows similar to those which came with the vehicle (elbows which have the notch in the "side" and rectangular holes in the inner face of the elbow).

If anyone can explain what is going on here then please feel free to tell me what I have missed. Confirmation of my assumption shall be appreciated.

Assuming that the replacement bows are usable... then where can I get elbows similar to the old / green items shown in the above photos?

thanking you for your assistance, Graham

Well quite a comprehensive 1st post, I do however think its nice to post in the intruduction thread to start before too many questions.....but welcome anyway.

Well quite a comprehensive 1st post, I do however think its nice to post in the intruduction thread to start before too many questions.....but welcome anyway.

Graham

I went through this exercise on my own 353 truck a year ago....firstly looking at your top bows,,,they don,t seem very " bowed ". to me

to get my new metal corners or bows to work I needed 6" inches of "bow " in the wood to get the angle correct. this is from the underside of the bow to a datum. The top bow by the way need to be 68 1/4 inches long. I steamed new ones from Oak to work.

The correct metal bows are available from the normal Dutch suppliers or Rex Ward sometimes carrys them or can get them in.

If the top bows are straight or straightish the corners bend to suit ( they are fairly flimsy ,,I put 3 tack welds on each new corner to strengthen them ) and the side strakes bulge outwards, reducing rear vision and making the tarp sit as a 3 sided box, rather than having a pronounced bow or radius at the top at the top. Most trucks seen to be in this catorgory as over the years the top bows collapse due to tarp weight. Look at pics of trucks during WW2 and you will see a pronounced roof radius...

Hope this helps.

Graham

 

I went through this exercise on my own 353 truck a year ago....firstly looking at your top bows,,,they don,t seem very " bowed ". to me

 

to get my new metal corners or bows to work I needed 6" inches of "bow " in the wood to get the angle correct. this is from the underside of the bow to a datum. The top bow by the way need to be 68 1/4 inches long. I steamed new ones from Oak to work.

 

The correct metal bows are available from the normal Dutch suppliers or Rex Ward sometimes carrys them or can get them in.

 

If the top bows are straight or straightish the corners bend to suit ( they are fairly flimsy ,,I put 3 tack welds on each new corner to strengthen them ) and the side strakes bulge outwards, reducing rear vision and making the tarp sit as a 3 sided box, rather than having a pronounced bow or radius at the top at the top. Most trucks seen to be in this catorgory as over the years the top bows collapse due to tarp weight. Look at pics of trucks during WW2 and you will see a pronounced roof radius...

 

Hope this helps.

We also used oak when we replaced our wood work, I'm not sure that's the wood that was used back then.

We also raised our side uprights by a couple of inches just to give a more practicle headroom inside. Not everyone will agree but it helps, we also can't find 1940's petrol.........

... I do however think its nice to post in the intruduction thread to start before too many questions...

Thank you, I have posted an introduction.

We also used oak when we replaced our wood work, I'm not sure that's the wood that was used back then.

One of the painted strakes that came with the vehicle had split lengthways and so revealed the colour and grain pattern of the wood. I took the damaged strake to a cabinet maker who identified the material as Keroin / Keruing - the corresponding entry in Wiki describes the wood as being used for the bed of lorries / trailers and with a brown, bland, appearance.

Keroin is not available from timber merchants in North Hampshire so Sapele was sourced and machined to provide material for six new strakes.

I have noted the discussion on length of strakes and the strakes which came with the vehicle differed in length by up to 2' so I guess that there had been some substitution. The replacement strakes were made to the longest length so as to provide a set of strakes of consistent length.

thank you and regards, Graham

....firstly looking at your top bows,,,they don,t seem very " bowed ". to me

 

to get my new metal corners or bows to work I needed 6" inches of "bow " in the wood to get the angle correct. this is from the underside of the bow to a datum. The top bow by the way need to be 68 1/4 inches long.

 

The correct metal bows are available from the normal Dutch suppliers or Rex Ward sometimes carrys them or can get them in.

 

If the top bows are straight or straightish the corners bend to suit ( they are fairly flimsy ,,I put 3 tack welds on each new corner to strengthen them ) and the side strakes bulge outwards, reducing rear vision and making the tarp sit as a 3 sided box, rather than having a pronounced bow or radius at the top at the top. Most trucks seen to be in this catorgory as over the years the top bows collapse due to tarp weight. Look at pics of trucks during WW2 and you will see a pronounced roof radius.

Thank you for your comments - I agree with you that the replacement wood bows do not have much "bow" or "rise". probably not much more than 2.5" in the centre. As to how much the bow needs to rise to work with the NOS elbows I have yet to estimate that figure.

My Son has spoken to Rex Ward - being not too far from where the 353 resides - and he had no parts to help when we asked late last year.

"Correct" bows and elbows - that is the krux of the matter, I just do not know which, if either, of our set of parts is correct for the vehicle. The replacement wood bows seem to be of correct length... which of the elbows is the one to go with?

Your comments about the curve of the top is how I read many of the photos of vehicles for the Normandy landings albeit there is more than one or two which have a flatter "top".

thank you, Graham

Thank you for your comments - I agree with you that the replacement wood bows do not have much "bow" or "rise". probably not much more than 2.5" in the centre. As to how much the bow needs to rise to work with the NOS elbows I have yet to estimate that figure.

 

My Son has spoken to Rex Ward - being not too far from where the 353 resides - and he had no parts to help when we asked late last year.

 

"Correct" bows and elbows - that is the krux of the matter, I just do not know which, if either, of our set of parts is correct for the vehicle. The replacement wood bows seem to be of correct length... which of the elbows is the one to go with?

 

Your comments about the curve of the top is how I read many of the photos of vehicles for the Normandy landings albeit there is more than one or two which have a flatter "top".

 

thank you, Graham

The problem with the flatter top is that water can gather and sit.

As already suggested might be worth trying some of the Dutch dealers, EG W.O.Wildenberg.

Word of warning they are not the cheapest and I know for a fact the prices depend on "accent's".However when buying parts for the Gmc or Dodge the quality has always been good......you just get that feeling that being English you are being "bent over the barrel" so to speak.

I bought a set of elbows for my son's GMC from LWD parts last year. They are identical to the ones you have bought and although I haven't tried them for fit yet I would imagine they are not correct. The reason being that I'm pretty sure they are ex French Army. I have bought a number of ex French Army parts for my Dodge in the past (not knowingly) and without fail they have been of poor quality and fit. These dealers don't distinguish between US and French manufacture and just list the parts as being NOS.........buyer beware!

I checked the new elbows against the originals on my son's GMC today. The original elbows have rectangular holes on the inside face unlike the NOS ones and the angle of the bend is smaller as well!

I checked the new elbows against the originals on my son's GMC today. The original elbows have rectangular holes on the inside face unlike the NOS ones and the angle of the bend is smaller as well!

So your "elbows", new and old, are like ours, at least I know in which way we ought to go... which is to find some more elbows with rectangular elbows in the inner face.

Anyone any ideas about a possible source of elbows with the rectangular holes?

thank you, Graham

There tends to be a correlation between non-availability of original parts and post-war pattern parts. If there was a ready supply of N.O.S. parts there was no need to reproduce them.

But this might be country specific, i.e. if the French were busy making new elbows there is a good chance you won't find any originals in France, but maybe somewhere like Norway still had a good supply of originals? Where did all the Norwegian spares go? Hewitt Marine couldn't have had the lot!

There is a way to ID original WWII CCKW corners. There is a notch in the flange that is not present on post war parts.

https://www.tm9-801.com/forums/viewtopic.php?f=2&t=627&p=1277&hilit=corner#p1277

And the proper dimensions for bows (and how to actually bend them) are posted here https://www.tm9-801.com/forums/viewtopic.php?f=2&t=1083&p=2382&hilit=corner#p2382

I posted the proper height for the staves on this board a while back, search for staves.

Avoid Red Oak if you can.