Chevrolet C8 1940 Cab 11 restoration, The Netherlands

[Bob Carriere]

Amazing these CMO have lasted so long when one considers the rush in which they were built......

Never seen such and extractor for broken taps....... quite the tool.

There are very few time that a welded nut on a stud will not work...... in such instance apply mega heat on the casted piece might have done the trick.......

Nice work Alex.....

Cheers

[Russ Gregg]

I have a full set of those 4 flute Walton tap extractors in my tool box at work, unfortunately they always buy 3 flute taps.

[Alex van de Wetering]

Guys, Thanks for your comments.

Bob, sadly I didn't have the tools to get enough heat in the metal. Drilling was OK, but the challenge was keeping the drill straight as it seemed the casting was far easier to drill into than the old bolts
Of course the tap broke in the last hole as I was rushing to get the job done, before it got too dark!

Russ, the Walton tap extractors are also available for 3 flute taps....and even for 2 flute taps! Maybe you have to convince the guys at work to buy matching taps.....or just don't break them

Alex

[Alex van de Wetering]

It was about time to spend some time on the driveline of the C8......starting with the transmission and slowly preparing to move to the engine.


I removed the transmission from the engine and chassis some years ago and it was patiently waiting ever since. It was hard to even see the actual transmission through all the layers of dirt, oil and grease. The gear lever was pretty much seized, as well as the small lever for the reverse gear. I had already treated some of the parts with penetrating oil, but even then the gear lever hardly even moved.

After removing all the grime, from the exterior of the box, I was able to remove the universal joint and the gearbox cover/shift tower with the gear lever still attached.

Inside it wasn't looking all that bad....and it even had some oil in it. The sliding gears however were seized to the shaft.
As you can see in the pictures, a previous owner added and extra lever and additional shaft… probably to drive some sort of wrecking gear. With help of Frank von Rosenstiel I have since found out my C8 was used as a tow vehicle in a Toronto used car lot, before ending at a farm vehicle in Pefferlaw, Ontario.

The extra gear and shaft were easily removed…and after liters of penetrating fluid, some heat and some gentle persuasion, the sliding gears moved again and I was able to disassemble the transmission.

Alex

[Alex van de Wetering]

Some years ago I bought a spare civvy 4 speed Chev transmission from the web, but never looked at the internals of the box. So, now was the time. Both transmissions boxes were disassembled and after cleaning everything I started comparing the parts from the two. At first everything seemed the same, but than I found out the sliding gear of the spare box had one more tooth than the one from the original box....and I found out the main shaft of the spare box was slightly shorter than the one from my C8.

The bearings in both the original box as well as the spare proved to be in good condition, but sadly I found out the mainshaft front bearing (the cage one with the long needles) in the original box was gone....I only found a bunch of the needles....and, after close examination, one end of the bearing cage. Sadly the lack of a proper bearing, meant the inside of the main drive gear was very beaten up, as was the end of the main shaft.

After checking the parts manual I found out all CMP 4 speeds use the same main shaft....even though the u-joint setup of the C8 differs from it's bigger sisters. Tracing the partnumber in a master parts list, I read that it was supposed to be 10,5” long.....a 11” main shaft is also listed, but not used on CMP's. To cut a long story short, it seems the main shaft of my C8 box was replaced at some stage for an 11” replacement. The spare box had a 10,5” shaft....and above all the end of the bearing surface on the end of the shaft was in good condition, so I used that one....combined with the spare main drive gear ......and selected the best parts of the two boxes to rebuild the gearbox.

Alex

[Alex van de Wetering]

I am hoping one of the fellow C8 owners can help me out on the following.....I can't figure out the universal joint!

After cleaning the grease from the parts I found out my C8 has a mismatch of yoke and spider, and some things are welded to make it work.....I have a feeling the rearmost yoke that attaches to the drive shaft is the original C8 part....and the front yoke with gear for the speedo is from something else.(?)....but I am not sure.
I have checked the parts manual, but I haven't been able to find the parts numbers in the master parts list. So, basically....before I can start searching for the correct parts, I have to find out what they actually look like! Anyone have a picture of the proper joint???.......the C8 setup is not shared with C15 or any other of it's sisters.

Another thing I wonder is if I have the proper “trompet” shaped "ball collar" that protects the U-joint from the outside world.......it has the remains of a seal at the rear end, but it doesn't seem to have a screw-on cap as I have seen on other (civvy) examples.

Alex

[Mike K]

Alex

I can help you

The C8 uni joint and drive shaft design , is from the USA 1940 1/2 Ton pickup with 4 speed gearbox . The 4 speed gearbox was an option on the 1940 1/2 Ton pickup, you could order either a 3 or 4 speed gearbox.

My uni was broken, it seems to be a weak point in the driveline. Maybe Jim carter can help you.