The Stovebolt Site Forums The Parking Lot Big Bolts 1966 C50 4x4

I just picked up this 1966 C50 (K50?) 4WD. Can anyone tell me what brand is the front axle? It looks like a NAPCO (I have a '59 NAPCO 1/2T) but no markings on it. Also, anyone know where to look for locking hubs for this? It has drive flanges, so front end turns all the time. Thank you!

Nice find.

Ed

That is a cool truck. I don't know anything about the front axle setup, but I'm sure someone in here does.

Very cool truck! Could it be a Coleman axle?

Most Coleman axles have a very large hub the wheel mounts to, doesn't look that way, px of hub would tell. There could be ID marking stamped on the axle tube, a good excuse the clean axle thoroughly.

Your picture indicates not a Coleman. Some old IHC trucks had Warn hubs for this hub.

Ed

Here is a picture of the hub...

Nice truck!

I think Warn made lock outs for that style hub. Likely long out of production.

Or maybe this one: https://www.summitracing.com/parts/...mFhYoJQTTgK4C4FYd_pb4VwiyGIaAl6mEALw_wcB

On old Jeeps prior to the locking hubs, they used to mill the splines out of the caps. Then carry a wrench and a stock set for when they wanted to use the 4wd, swapping the caps. Not real convenient but do-able.

Cool truck! Front axle/hub doesn't look Coleman. I does look like a NAPCO, but didn't GM make their own 4x4 driveline by 1965? Locking hubs do surface once in a while, I would suggest that you take off the current drive hub to see what type of splines you need on the locking hub.

I don't think Chevrolet ever built a 4x4 larger that 1-ton...I believe the larger trucks were all done by the dealer or owner, not factory.

Wasn't 1959 was the last for NAPCO in factory builds and 1960 the start of GM/Dana front 4x4 axles?

Mike B

Starting in 1960 1 ton and bigger trucks were still done by napco into the 70s, the 1/2 and 3/4 tons were factory closed knuckle dana 44s with Rockwell 221 transfercases

I believe you guys are right, 1960 was the first year of the 1/2T 4x4s and they were built by GM with Dana 44 axles. All previous were 3/4T Napco's. My '62 has a Timken 4 shaft transfercase, same thing was used in Duce-and-a-half's, it has provisions for a PTO to the rear and a second rear axle. Rockwell might be the same thing as Timken, I don't know about that. The transfercase was used with small mods for quite a few years after that, perhaps to 1970 or so. Eventually it was mated directly to the transmission. Mine is divorced, I am sure that is a holdover from the Napco "kits", no engineering required as with a mated case. I believe but have no data that the larger trucks used the very same setup with rear axle assemblies cut and knuckles added by Napco for the front and the same transfercase.

The hubs you posted the link for are for something smaller (1 ton), the Summit link said Dana 60 & 70 external hubs, 3 9/16" bolt circle. I measured a spare drive flange that came with my C50 and it's 8-bolt circle is 5", and the spline count is 16, and axle diameter to bottom of spline is 1 9/16" (or thereabouts). I am going to have to scour the USA to find locking hubs! Any input/leads as to who might have them (old wrecking yards that deal in 2 ton trucks, etc.) would be appreciated.

Also, the NAPCO 4WD units were line-installed in GM 1/2 & 3/4T trucks from late 1957-59, using a Dana 23 transfer case. Ford used a mirror image of the Dana 23, it was named Dana 24, and was used into the 1970s, before going to the NP203 or NP205 cases. The 1960-69 Transfer cases used in GM 1/2 and 3/4T is the Rockwell/Timken T221 like you mention. In 1967 GM married it to the manual trans, either 3 or 4 speed. Discontinued after 1969, and was never married to an auto trans. The NAPCO front ends for 1/2 & 3/4T were discontinued after 1959, replaced by the Dana 44 for 1/2 & 3/4T from 1960 on until 1977-80. The NAPCO front ends used the same drop-out 3rd member/differential as the rear end of the truck, whether 1/2 or 3/4T. One note on the Dana 23 transfer, it was not used in 1955, beginning in use in 1956. 1955 and older NAPCO conversion transfer cases were different (I'm not sure what brand, would guess Rockwell/Timken) in that the front output was on the driver's side (like a Ford transfer). Also, the front end on a 1/2T was 8 lug! The rear end was the standard GM 1/2T rear, but with wheel adapters to convert to 8 lug! I know this due to having parted out a 1955 Suburban 4x4 that had this setup in it. I believe the same set up was used in pre-1955 4WD conversions, but am not privy to those, as I only concerned myself with the 1955-1959 NAPCOs in my 30 years of toying with these things!

Regarding transfer case for trucks bigger than 1 ton. The Rockwell/Timken T223 was used, and looks like a 50% bigger T221. I included a picture of one here. I have a Ford version of a T223 (taken from a 1959 F600 with Marmon Herrington 4WD conversion) and it is the same as GM used except the front output is on the driver's side. In my C50, it does not have a T223, and I am trying to figure out what it is (need to crawl under it and look for numbers). It may be a T226 case.

Oh well, I love researching these odd-ball 4WD trucks! I thought the NAPCO was hard to find info on! NOPE! These bigger (over 1 ton) trucks are MUCH harder to find info on!

Chevrolet also offered the NAPCO 4WD 1-ton trucks from 57-59 with a 3500 pound axle rating...

Mike B

You guys know more about this than I did, (thanks for educating me).

The picture of the T226 has a dirty adapter sitting next to it, what is that for?

As previously stated, NAPCO wasn't used on the light duty trucks after 1959 except for some 1 ton conversions since GM didn't offer a factory 4x4 1 ton (k30) till the mid to late '70's ('77 I think).

From what I've seen, NAPCO continued upfitting GM medium duty trucks into the '70's and possibly early '80's well after the light duty days were over.

Amazing truck by the way. You should sell it to me

That is a PTO extension housing, mounts to the other side (the side you can't see) of T-case in the picture.

Also, since I am a squarebody (1973-1987) aficionado also, GM offered factory/line-built 1 tons beginning in 1977 and used Dana 60s for the front-ends. As 'whateverpratt' says above, NAPCO did GM trucks 1ton and over up through the 70s, and possibly later for the 2 tons and up.

Correct Mike! I had to go pull my 'Truck Data Books" to see for myself. GM did make 4WD 1 tons till 1959, then from 1960-1976 did not produce any line-built/factory 4WD 1 tons, they all were up-fitted after factory delivery.

Great stuff. NAPCO was located in a large building in Hopkins, Mn, a couple miles from where I live. They have moved down the street, but I don't know what they do these days. The old building still stands empty but has been purchased by the local government. the land will be used for some purpose related to a transit rail boondoggle that is being built. I expect the building will be demolished during the coming winter. I have a sales brochure around here somewhere that includes some original 8x10 photos of the "Chevrolet Mountain Goat" in action, a converted 3/4T panel truck.

All good stuff here!

Ken, I see you list your all of your trucks in your signature and you call the wrecker a K50...technically Chevrolet never made a K50, so you have a C50 with an up-fitted NAPCO 4WD front axle...



Mike B