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-   -   HUP restore in Sask (http://www.mapleleafup.net/forums/showthread.php?t=29582)

ahleeds 21-11-18 00:57

HUP restore in Sask
 
3 Attachment(s)
Hello
Im knee deep in this new vehicle , ive hit a road block with the transmission . It was full of water so im wondering if anybody has any gears for this
1943 Hup Pers-1
Chev sm420 trans
casting 590474
Thanks Anthony

and if anyone is wondering on a transmission color there is a lot of original kakki olive paint all over this one.

Grant Bowker 21-11-18 03:24

Are you sure that you have a SM420 transmission?
I have understood that the SM420 had synchromesh 2nd to 4th and I usually think of synchromesh as having helical, constant mesh gears rather than the straight cut gears in your photo.
Some online sources give the part number 590474 as being a 4 speed transmission as early as 1931 which feels early for a truck to have synchromesh.
Some characteristics of your photos resemble standard 4 speed of the CMP era but I don't find the part number 590474 in the CMP manuals I checked. The "retainer, clutch gear bearing" 591327 does appear in CMP manuals and is listed as 1938-46 in a Master Parts Catalog. (590474 doesn't appear in the same master parts catalog applying to 1929-48 so may be a later than '48 number).
I think that GM basically assigned part numbers sequentially so early parts have lower numbers, parts designed at the same period have similar numbers etc.
I hope I'm not making you as confused as I feel.

Looking at your photos, I wouldn't give up on the gears. I suspect a good wirebrushing or scotchbrite pad buff would make them usable (subject to inspection after cleanup). Some simple old mechanisms are remarkably tolerant of imperfections.

Harry Moon 21-11-18 03:33

Looks good
 
Unless there is some damage I don’t see it looks pretty good. I recommend getting a new from input shaft bearing a sealed version and pull out the neoprene seal on the inside. Check the cage bearing and I often see the rear seal on eBay.

ahleeds 21-11-18 05:29

Rotten teeth
 
So it isn't a sm420 but the earlier 31-48 predecessor.
Normally I would buff up the gears and carry on ,but the rust ate 3 teeth off third and the rest don't look much better.
If I was to run this pitted up gear set it would be so loud in the cab you'd need good ear plugs .
Anthony

Tony Smith 21-11-18 07:51

2 Attachment(s)
Although the CMP parts books list the transmission casing as being Pn 590524, it seems that 590474 is a common alternative.

I have 2 Chev CMP gearboxes with the casing number 590474.

The mainshaft 3rd gear is pn 590493, while the countershaft 3rd gear is pn 590502, both available NOS from a variety of sources.

Phil Waterman 21-11-18 15:13

I would not give up on this box
 
Hi Anthony

I would not give up on this box, rust on gears often looks far worse than it is. Two of my CMPs had transmissions as bad or worse than this, and they both clean up and have many thousands of miles on them after going back on the road.

I started by removing the bearings then polishing each gear tooth with 3M rowloc pads, used old wheels with most of the abrasive worn off, with a very light touch, object remove and smooth the surface. I didn't try polish out the pits, leave the pits alone.

Take a look at the photos http://canadianmilitarypattern.com/C...ansmission.htm it shows, primarily, the transmission in my C60S as I started 1990 and then 2008 and 12000 miles later. When the main shaft got noisy and had to be replaced, new shaft and it ran for another 10,000 miles before breaking a tooth. http://canadianmilitarypattern.com/3...ansmission.htm

That time I got lucky and found a NOS gear box, can we say scarce as hens teeth. Yes, I did find a replacement gear and rebuilt the first transmission, which with three CMPs on the road sits on the shelf full of gear lube ready to go in.

Back to my point, if the gears and bearings areas clean up it will probably give many thousands of miles.

Keep us posted on your progress.

Cheers Phil

PS I'll look to see which of my photos need to be moved to MLU.

Jordan Baker 21-11-18 16:38

When I rebuilt mine i put all new bearings in it and also a new rear seal. The rear seal has the sheet metal tabs spot welded to it. I also replaced my shift forks as they were worn. I found all of the parts on ebay.

Harry Moon 21-11-18 17:57

Quote:

Originally Posted by ahleeds (Post 255924)
So it isn't a sm420 but the earlier 31-48 predecessor.
Normally I would buff up the gears and carry on ,but the rust ate 3 teeth off third and the rest don't look much better.
If I was to run this pitted up gear set it would be so loud in the cab you'd need good ear plugs .
Anthony

Loud is normal, at highway speed I use a com set just to talk to the passenger. Straight cut gears in the transmission and transfer case will do that!

ahleeds 21-11-18 18:50

Gear closeup
 
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Looks like this gear was on the meth pipe

Phil Waterman 21-11-18 19:45

Yup the metal mice have been at them
 
Quote:

Originally Posted by ahleeds (Post 255942)
Looks like this gear was on the meth pipe

Yup those are definitely past the polish and put it back together.

Though back in the day my brother had a Model A where the teeth looked like that and some mechanic had carefully brazed and filed each tooth back to shape. But boy was it load, he replaced the gears.

That photo is a classic "it ran when parked"

Cheers Phil


Is that the only gear that is bad? Interesting because that looks like the 3rd gear lower cluster gear which is the same one that my C60S broke a tooth out of, which I was able to find a NOS gear and replace it.

maple_leaf_eh 21-11-18 20:14

Advice from the cheap seats
 
Quote:

Originally Posted by ahleeds (Post 255942)
Looks like this gear was on the meth pipe

Hmmm? In your situation, maybe you want to invent a jig to hold the rotten gear and then stock up on good quality welding wire? Or, pause the project until you can source a better looking gear.


BTW, I visited Moosomin many times when driving East/West on No. 1. The namesake of my street in Regina, Harry Mullin VC, is buried south of town.

Bob Carriere 21-11-18 20:58

Gears are available.....
 
Hi Anthony

Gear clusters are available....maybe not new but in good shape. I have opened more than one tranny over the years and although the box was half filled with water and bearings might have been pitted the gears were always good. Seals and bearings should be available from industrial dealers like General Bearing Services by size...OD and ID. A complete tranny from a junk yard may be much cheaper than a single gear retail....just remove the cover and spin the gear around for inspection. Easy to mail but expensive by weight. Sometimes the gears can be chipped or worn from lack of synchros but if not too bad can be dressed up with a grinding wheel. I have some available if you get desperate but postage from Ottawa, when they work, would be high.

Yours are beyond recovery and will no doubt chip and cause further damage to other gears.

Good luck and keep us posted by photos of your progress.

Jordan Baker 21-11-18 21:58

Just buy the individual gears NOS off of ebay. The MB-C2 manual gives a great run down on how to replace the gears. its very easy to do.

Phil Waterman 21-11-18 23:34

There are two different 3rd gears
 
Hi

In your search for a replacement gear check the number of teeth, if memory serves there are two different 3rd gears with different diameters and different numbers of teeth so you need the one you have to match the upper gear cluster.

Cheers Phil

ahleeds 12-12-18 18:10

Found a rebuilt trans
 
2 Attachment(s)
Phoned up Asperline Transmission in Winnipeg and he had one sitting on the shelf .
Was rebuilt and left there 20 yrs ago.
Felt pretty lucky to get one that easily.
I gladly paid him 500.00

Phil Waterman 12-12-18 23:57

Good find
 
Hi

When I found a NOS transmission few years ago, it still needed to be taken apart and cleaned. Hope you can also find the parts to repair the other transmission, always good to have a spare, to use or as trading material for some other major part.

Cheers Phil

ahleeds 13-12-18 19:11

Points
 
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Rolled out the points tool kit
Not sure if it's ww2
Or home made but it's got everything
Fireing up the new engine

Bob Carriere 13-12-18 23:25

New rebuilt?????
 
Don't forget to use Zinc additive to the oil.....

Or HD diesel engine oil....

run at a fast 1000 rpm idle for at least 30 minutes to let things fit together.

Good luck

PS what plugs are you running???

ahleeds 26-05-19 16:50

Two into one
 
2 Attachment(s)
Finally looking HUP like
I will align the frames and weld it all together now
The front dash is original,the back body was a replacement.
This pile of parts was bought from cletrac last year

ahleeds 26-05-19 17:15

Some before pictures
 
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Loaded for home

ahleeds 28-01-20 00:37

Body work
 
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Some of the winter progresses on the HUP .
Burning through the grinder discs and mig wire.

Any chance someone has a spare RH door ?

ahleeds 05-02-20 00:36

Just in time
 
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Found these beauties just in time .
Was all set to make a pair.


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