1943 Ford GPW Build from Rescued 1943 Parts

If you have an unrestored WWII jeep, we would like to see pictures, and hear your comments. NO EBAY or COMMERCIAL SALES.
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Re: 1943 Ford GPW Build from Rescued 1943 Parts

Post by JAB » Wed Jan 25, 2023 3:58 pm

70th Division wrote:
Wed Jan 25, 2023 3:31 pm




For the MB, the new ring, pinion, and carrier are NOS Ford parts . Most GPW pinions don't seem to be enscribed as to pinion depth, so you'll probaby have to start with about 0.065" under the inner bearing and then measure it and try to get close to zero to start.

I will be getting to it soon, once the depth setting plate arrives, and the dial indicator arrives , and the inch pound T- wrench arrives to determine the rotational torque. Be careful! Buying these tools is addictive! And all of your friends will either want you to set up their differentials or borrow the tools!


I will use the dial indicator first on the GPW engine, to determine what the end play is, since the feeler gauge is giving me
2 separate readings based on either the upper bearing, or the lower bearing.
.004 for the upper, and .006 for the lower.
Is that normal, or is it only checked on the upper bearing gap between the thrust washer and bearing as depicted in the less than helpful manuals ? I doubt it's normal, especially on a bearing with some run-time, but I've never measured it that close. I just checked the gap, and if in spec, moved on. A dial indicator would never catch that as it only measures total movement.

If the dial indicator is set up , where does the tip get placed , on the edge of the crank nut after it is tightened down ? On any smooth machined surface that's solidly connected to the crank. The end of the crank, the flywheel, the machined surface for the flywheel, the face of the timing gear, etc. Install the indicator and get it to read "something" (you can carefully turn the face so it reads zero, but it's just easier to do the math) then move the crank with a prybar and get the totals from the dial. If you start at 0.008" (the "something") and it goes another 0.001" to 0.009" in one direction, and then force it back the other way and it reads 0.004" you've got total endplay of 0.005" (0.009 minus 0.004 equals 0.005") The 0.008" was only to ensure that the end of the indicator was actually and always in contact with the machined surface. you could have forced the crank all the way in one direction and set the dial to zero, then just read the total after forcing it in the opposite direction

I will post some pictures of what I did today on the end play investigation.


Best Regards,
Ray
-Jeff

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Re: 1943 Ford GPW Build from Rescued 1943 Parts

Post by 70th Division » Wed Jan 25, 2023 4:01 pm

Jeff ,

Here is what I found today trying to figure out the end play.
Resized_20230125_093908(1).jpeg
I don't know what the scrapes or gouges are for in the edge of the bearing.
Update- Thanks to Jeff, these gouges are oil passages, great to know !!
They are on both sides as I removed the bearing cap and looked at the bearing.
Resized_20230125_094235.jpeg
Here are the shims I added, after I removed everything this morning.
The shims are around the crank shaft, but since the crank shaft tapers at the end, we can see the shims are pressed to fit around the taper.
Resized_20230125_103706.jpeg
Here we see where the taper is, that the shims are pressed onto .
Resized_20230125_104617.jpeg
Here we can see some deviation between the upper bearing and the lower ?
This was corrected when I put the upper bearing cap back on the crank.
Resized_20230125_103443.jpeg
I removed the upper cap and bearing, this is what the crank looks like under the bearing.
I did wipe all the oil off to get a clean picture of what it looked like.
Resized_20230125_103450.jpeg
Resized_20230125_103627.jpeg
This ugly scratch was found on the inside edge up the upper bearing, facing rearward.
Resized_20230125_103233.jpeg
The bearing.
Resized_20230125_104623.jpeg
What is this, hammered ? A little marked up.
Resized_20230125_103546(1).jpeg
The inner facing edge of the bearing, it has the same type marks in it,as the front, these are oil passages.

Best Regards,
Ray
Last edited by 70th Division on Tue Jan 31, 2023 11:26 am, edited 5 times in total.

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Re: 1943 Ford GPW Build from Rescued 1943 Parts

Post by JAB » Wed Jan 25, 2023 4:12 pm

While not measuring end play, here's a couple of pictures of how to use the dial indicator the verify that the differential case is true and worth using. This particular indicator has a ball on the end of a stick that you can "snap" into various positions to get a good angle for access to the surface being measured. Another type uses a plunger that is a bit more limited in that it has to be fairly square to the surface your measuring. For the type of work I do I find the first type more versatile, but both types have their place. The plunger style is considered to be more precise. In this instance, after setting up the indicator you set your zero ("something") and then rotate the carrier. If the indicator measures more than a total deviance of 0.006" the carrier is sprung (not true) or some other problem exists (dirt between ring gear and carrier?).
IMG_0338.jpg
IMG_0337.jpg
-Jeff

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Re: 1943 Ford GPW Build from Rescued 1943 Parts

Post by 70th Division » Wed Jan 25, 2023 4:16 pm

JAB wrote:
Wed Jan 25, 2023 3:58 pm
70th Division wrote:
Wed Jan 25, 2023 3:31 pm




For the MB, the new ring, pinion, and carrier are NOS Ford parts . Most GPW pinions don't seem to be enscribed as to pinion depth, so you'll probaby have to start with about 0.065" under the inner bearing and then measure it and try to get close to zero to start.

I will be getting to it soon, once the depth setting plate arrives, and the dial indicator arrives , and the inch pound T- wrench arrives to determine the rotational torque. Be careful! Buying these tools is addictive! And all of your friends will either want you to set up their differentials or borrow the tools!


I will use the dial indicator first on the GPW engine, to determine what the end play is, since the feeler gauge is giving me
2 separate readings based on either the upper bearing, or the lower bearing.
.004 for the upper, and .006 for the lower.
Is that normal, or is it only checked on the upper bearing gap between the thrust washer and bearing as depicted in the less than helpful manuals ? I doubt it's normal, especially on a bearing with some run-time, but I've never measured it that close. I just checked the gap, and if in spec, moved on. A dial indicator would never catch that as it only measures total movement.

If the dial indicator is set up , where does the tip get placed , on the edge of the crank nut after it is tightened down ? On any smooth machined surface that's solidly connected to the crank. The end of the crank, the flywheel, the machined surface for the flywheel, the face of the timing gear, etc. Install the indicator and get it to read "something" (you can carefully turn the face so it reads zero, but it's just easier to do the math) then move the crank with a prybar and get the totals from the dial. If you start at 0.008" (the "something") and it goes another 0.001" to 0.009" in one direction, and then force it back the other way and it reads 0.004" you've got total endplay of 0.005" (0.009 minus 0.004 equals 0.005") The 0.008" was only to ensure that the end of the indicator was actually and always in contact with the machined surface. you could have forced the crank all the way in one direction and set the dial to zero, then just read the total after forcing it in the opposite direction

I will post some pictures of what I did today on the end play investigation.


Best Regards,
Ray
Thanks Jeff,

Excellent information !!!
I am looking forward to the tools arriving !!

Ray

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Re: 1943 Ford GPW Build from Rescued 1943 Parts

Post by JAB » Wed Jan 25, 2023 4:18 pm

Ray,

The big "gouges" are made there to allow oil to leave the bearing and lube that face. I hope the bearings are oiled, not dry! That damage on the back won't hurt anything, but it shouldn't be scraped like that. If any "hard" metal is embeded in that mark it might be best to carefully pick it out. Is it possible that the front cap was installed backwards? I'd have to check, but I know it's easy to install at least one of these backwards if your'e not paying attention. Didn't you find some other issues with this engine? That bearing doesn't seem to be "right", as far it how it fits. Best to check everything now.
-Jeff

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Re: 1943 Ford GPW Build from Rescued 1943 Parts

Post by 70th Division » Wed Jan 25, 2023 4:30 pm

JAB wrote:
Wed Jan 25, 2023 4:12 pm
While not measuring end play, here's a couple of pictures of how to use the dial indicator the verify that the differential case is true and worth using. This particular indicator has a ball on the end of a stick that you can "snap" into various positions to get a good angle for access to the surface being measured. Another type uses a plunger that is a bit more limited in that it has to be fairly square to the surface your measuring. For the type of work I do I find the first type more versatile, but both types have their place. The plunger style is considered to be more precise. In this instance, after setting up the indicator you set your zero ("something") and then rotate the carrier. If the indicator measures more than a total deviance of 0.006" the carrier is sprung (not true) or some other problem exists (dirt between ring gear and carrier?).IMG_0338.jpgIMG_0337.jpg
Very nice information Jeff !!

I see you have a Starrett dial indicator, I have been looking at a lot of nice tools on ebay :D


I see some great tools available there, so will be doing a lot of general shopping for important tools to have in the shop !


Best Regards,
Ray

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Re: 1943 Ford GPW Build from Rescued 1943 Parts

Post by 70th Division » Wed Jan 25, 2023 4:48 pm

JAB wrote:
Wed Jan 25, 2023 4:18 pm
Ray,

The big "gouges" are made there to allow oil to leave the bearing and lube that face. I hope the bearings are oiled, not dry! That damage on the back won't hurt anything, but it shouldn't be scraped like that. If any "hard" metal is embeded in that mark it might be best to carefully pick it out. Is it possible that the front cap was installed backwards? I'd have to check, but I know it's easy to install at least one of these backwards if your'e not paying attention. Didn't you find some other issues with this engine? That bearing doesn't seem to be "right", as far it how it fits. Best to check everything now.
Hello Jeff,

That is good to know about the gouges, as they are not made uniform, but I see them on an engine on youtube as well.
When I took the upper bearing cap off, there was oil under it, so it looked well oiled.
I haven't gotten into the engine further, but under the timing chain cover many issues with missing bolts, worn sprockets, missing shims,stretched original timing chain, also the old head studs and bolts were reused, the old manifold studs were reused as well.
The lock washers on the main caps are missing, but I have found new Ford ones to replace them, and all the pal nuts missing, I found nos ones,
but when I pull the pistons, I will know if the rings were installed in the correct fashion.

The cylinder walls look perfect, the pistons are new, as are the valves and springs.
It has a replacement oil pump, that will be replaced with an original GPW one, and the oil sump strainer will be replaced with an nos Ford one.

The head wasn't torqued down, the head gasket was rusty on both sides of it, I am surprised the bubba sand mechanic who put this engine back together, didn't toss an obligatory handful of sand in the engine.

But, inside the block looks spotless and clean, as does everything.

Plus there may be a leak in the distributor tunnel, which I will seal with a copper pipe inserted in there.

However, I think it will all be good again once I get the end play set, and verified with a dial indicator gauge, and can move forward.


Best Regards,
Ray
Last edited by 70th Division on Sun Jan 29, 2023 8:34 pm, edited 1 time in total.

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Re: 1943 Ford GPW Build from Rescued 1943 Parts

Post by JAB » Wed Jan 25, 2023 5:44 pm

Ray,

Based on what you said, especially concerning loose head bolts/studs, I suggest you completely disassemble the engine (which you already pretty much admitted you were going to do) and inspect everything as you verify each item in the manual. Folks with much more experience would do that as a minimum, especially after finding what you already found. I still wonder if that front bearing cap was installed backwards. Are the little bearing retainers installed in the bearing caps to keep the shells from spinning? I'm glad it's clean, that's a big advantage, but there's so much more to check. Have you measured the bore for taper or other problems? Is the crosshatch from honing still visible? You don't trust the rings for a reason; why not? Instinct? Something the guy said about how it ran? Also, the early manual had an error that had the connecting rods installed the wrong way; which way did he install them? The little squirter hole (there's a boss on both sides of the rod but only one side is drilled) that sprays away from the camshaft (opposite of what you'd think!) when installed correctly. The valve clearance needs to be 0.0014 (or is it 16?) any less and you can burn the valves over time. The top two rings need to be installed with a certain side facing up. Lots of little things with big consequenses. Did you run it? Did it have good oil pressure? Did it run smooth? Was there good compression? So much to go wrong!
-Jeff

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Re: 1943 Ford GPW Build from Rescued 1943 Parts

Post by 70th Division » Wed Jan 25, 2023 6:02 pm

JAB wrote:
Wed Jan 25, 2023 5:44 pm
Ray,

Based on what you said, especially concerning loose head bolts/studs, I suggest you completely disassemble the engine (which you already pretty much admitted you were going to do) and inspect everything as you verify each item in the manual. Folks with much more experience would do that as a minimum, especially after finding what you already found. I still wonder if that front bearing cap was installed backwards. Are the little bearing retainers installed in the bearing caps to keep the shells from spinning? I'm glad it's clean, that's a big advantage, but there's so much more to check. Have you measured the bore for taper or other problems? Is the crosshatch from honing still visible? You don't trust the rings for a reason; why not? Instinct? Something the guy said about how it ran? Also, the early manual had an error that had the connecting rods installed the wrong way; which way did he install them? The little squirter hole (there's a boss on both sides of the rod but only one side is drilled) that sprays away from the camshaft (opposite of what you'd think!) when installed correctly. The valve clearance needs to be 0.0014 (or is it 16?) any less and you can burn the valves over time. The top two rings need to be installed with a certain side facing up. Lots of little things with big consequenses. Did you run it? Did it have good oil pressure? Did it run smooth? Was there good compression? So much to go wrong!
Hello Jeff,

Yes I am going to go through everything since things seem to need attention.

I have never run it, the seller said he ran it for a short period but it didn't run well, and shut it off, but it was sitting a long time and had a frozen, rusted in distributor, and likely a clogged carb.

The jeep came from a museum, and was a matching number GPW.
The seller wasn't given much info on it, and didn't want to mess with the engine as it had coolant in the oil.

He actually bought a rebuilt GPW engine from Oz, that he is putting into the jeep.
I was lucky to be able to get this engine, as it looks like it will be a good engine, but needs to be checked over.

I am thinking the engine work was done by a competent machinist, but the other items were added back by a former owner, after it returned from the machine shop, which explains the old sprockets and chain being reused.
I also think the missing bolts may have been removed while the seller's mechanic took things apart to take a look, and weren't replaced before I got it.

It could not have run with the sprocket and timing chain loosened up, and the front pulley was removed as well.
Those items likely were on it when it was test run, but I think were removed before the decision to replace the engine with another rebuilt engine from Oz was made.
Resized_20230124_145159.jpeg
Resized_20230124_145152.jpeg
The rod numbers do all line up in order, the bearing caps are in the correct orientation, but since it is an easy process to remove everything and then replace, that is what I will do to double check everything.

I know it did run after the rebuild as there was carbon build up on the valves.


Best Regards,

Ray
Last edited by 70th Division on Sun Jan 29, 2023 8:40 pm, edited 3 times in total.

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Re: 1943 Ford GPW Build from Rescued 1943 Parts

Post by 70th Division » Wed Jan 25, 2023 6:18 pm

JAB wrote:
Wed Jan 25, 2023 4:12 pm
While not measuring end play, here's a couple of pictures of how to use the dial indicator the verify that the differential case is true and worth using. This particular indicator has a ball on the end of a stick that you can "snap" into various positions to get a good angle for access to the surface being measured. Another type uses a plunger that is a bit more limited in that it has to be fairly square to the surface your measuring. For the type of work I do I find the first type more versatile, but both types have their place. The plunger style is considered to be more precise. In this instance, after setting up the indicator you set your zero ("something") and then rotate the carrier. If the indicator measures more than a total deviance of 0.006" the carrier is sprung (not true) or some other problem exists (dirt between ring gear and carrier?).IMG_0338.jpgIMG_0337.jpg
Jeff,

How did your differential check out after using the indicator on it, was it in spec ?

Ray

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Re: 1943 Ford GPW Build from Rescued 1943 Parts

Post by JAB » Wed Jan 25, 2023 6:24 pm

The first of several was in spec and the last one was as well. Two or three were barely out of spec and are in a plastic milk crate with bad bearings and gears that I can no longer lift. I'll have to have my son move it or maybe make it into two boxes! I hate to take any WWII jeep parts to the scrapper but they are truely worn out and have no restoration value.
-Jeff

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Re: 1943 Ford GPW Build from Rescued 1943 Parts

Post by 70th Division » Wed Jan 25, 2023 6:36 pm

JAB wrote:
Wed Jan 25, 2023 6:24 pm
The first of several was in spec and the last one was as well. Two or three were barely out of spec and are in a plastic milk crate with bad bearings and gears that I can no longer lift. I'll have to have my son move it or maybe make it into two boxes! I hate to take any WWII jeep parts to the scrapper but they are truely worn out and have no restoration value.
Ugg,

That is too bad, but at least you have some good ones still in the batch.

The nos GPW ring and pinions on ebay are pricey, but remember that Staman has some Euro made ones for half that price, and some Euro parts places have later US made Spicer ones available at similar half the price off nos GPW ones found on ebay.

There are NOS carriers, as well as spider gears, available on ebay, if needed.

Maybe scrap prices are up, and you can raise funds for an nos one :D

Best Regards,
Ray

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Re: 1943 Ford GPW Build from Rescued 1943 Parts

Post by 70th Division » Sat Feb 04, 2023 10:38 am

Hello,

Today I have started back on the engine, since the proper instruments have arrived 😁 !

Setting up a digital dial indicator to measure the crank end play.

Having removed the front bearing cap, and checking it out, all looked good, so I torqued in back down with the new Ford lock washers.
I think this helped make the gap uniform between the thrust washer, shims, and front bearing.

I put 2 shims into position as before totaling .006 inches.

I set up the new dial indicator gauge with a magnetic base, and followed the procedure, pushing the crank all the way back, then once set up, all the way forward.

Setting up the probe at the .0000 reading, on 2 different locations.

The first test position was on the end of the crank nut, after all was tightened down.
Resized_20230204_140218.jpeg
The second probe test location was on the flat side of the crank pulley.
Resized_20230204_140758.jpeg
Resized_20230204_150851.jpeg
This reading was taken several times from each position.

All reading .008 inches.
This was also confirmed using the feeler gauge at .008 as well.


So, the manual says the end play reading desired is from .004 to .006.

It also says if it reads under .004 to add shims, and if over .006, subtract shims.

So I will remove a .002 shim, and start again, to see if I can get a .006 reading.

Ok I removed the .002 shim and got the following reading :
Resized_20230204_152759.jpeg
.0065, so it is over the spec by a tiny bit.

Next I took it all off again, and removed the. 004 shim, and replaced it with the .002 shim, and tightened everything down tight.

Here is the reading from
that effort :
Resized_20230204_154414.jpeg
All set it reads .0045 .

The question I have now, is there a preferred setting ?

.0045 or .0065 ?
Resized_20230204_154527.jpeg
I next checked it with the .004 feeler gauge.

I am happy either way !

Best Regards,
Ray

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Re: 1943 Ford GPW Build from Rescued 1943 Parts

Post by JAB » Sat Feb 04, 2023 6:51 pm

0.0045 is definately between 0.004 and 0.006 (think of it as 4-1/2 thousandths) so it's on the tighter end of the tolorance, which is great! Kinda fun playing wih new toys...I mean tools...isn't it!? and the fact that you could verify it with a tried and true means that you're already familiar with (feeler gauges) makes it even better.
-Jeff

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Re: 1943 Ford GPW Build from Rescued 1943 Parts

Post by 70th Division » Sat Feb 04, 2023 7:04 pm

JAB wrote:
Sat Feb 04, 2023 6:51 pm
0.0045 is definately between 0.004 and 0.006 (think of it as 4-1/2 thousandths) so it's on the tighter end of the tolorance, which is great! Kinda fun playing wih new toys...I mean tools...isn't it!? and the fact that you could verify it with a tried and true means that you're already familiar with (feeler gauges) makes it even better.
Thanks for that info Jeff !
So the lower end of the spec is good ?
These new tools are great, and make things much easier.
I like the digital read out with big numbers, and also that this dial indicator can do metric as well, if needed in a modern application.
I am actually looking forward to building the rear end on on the Willys MB with these tools !
If I can master that, I have several others to restore as well !

Now I can finish the engine review and any work needed, and also get the newly acquired GPW oil pump overhauled and installed, and the copper tube tapped into the distributor tunnel.


Best Regards,
Ray


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