F15a steering knuckles

[Jacques Reed]

Further to the part numbers previously listed:

The first digit after the "C" in the part number is the year the part was designed and released.

Therefore the knuckles starting with C1 were designed and released in 1941 and the one with the number starting with C0 were designed and released in 1940.

Points to early pre 1941 CMP F15A's had the two size studs on the knuckles and later they standardized them to the larger 1/2" diameter studs.

Both sides of my 1944 model have 1/2" diameter studs.

No doubt there would be exceptions due to using up old stock post 1941 and replacement parts.

I bought the early 7/16" stud NOS knuckle for a spare a while back and only realized the difference when I brought it home. Thought maybe it was for a Marmon Herrington afterwards so on the shelf it sits. Anyone want it?

Cheers,

[Jacques Reed]

Now I am confused (More so than normal!)

While putting away the knuckles I photographed for the earlier post I noticed the Part number C01Q 3358 cast into one of the knuckles as per the photo attached. None of the other two knuckles had any numbers cast into them.

Very different to the F15A parts list numbers I quoted.

It definitely came off a 4-7/8" steering end as used on the F15A. Still, as is often the case, it does not mean it is the correct one.

I don't have a parts list for the larger trucks with 6" steering ends and would have thought those knuckles would not be the same size but could it be?

Anyone able to shed some light on this one?

[Dave Schindel]

Tough one.....none of my knuckles have numbers,at least none that I could find.Just the Ford logo stamped on the inside near the bearing race.

[Dave Schindel]

Rob, I am guessing that the 1/2 in. studs were used where the steering arm attaches to the knuckle and the others were 7/16. Later they were all tapped to 1/2?

[rob love]

It would make sense, in the interest of carrying less spare parts in the supply system, to make the left and right the same. So to that end, you would have to go with 1/2 inch, since that was required to handle the load of turning 2 wheels. The left side only had to handle the load of turning one, so in that case 7/16 studs would have sufficed engineering wise.

Checked a 44 Chev 15cwt Sigs van that is apart and sitting about 30' from me. Sure enough, 1/2" threaded holes on the left side and the C01Q-3348 part number on the casting.

[Jacques Reed]

Hi Rob,

After reading about your part C01Q-3348 on A Chev CMP and my C01Q-3358 off a Ford CMP perhaps Ford assigned different numbers to parts earmarked for Chev truck production? Can anyone shed any light on that as I don't have any Chev Parts manual to check.

Have looked in my GM MB-C1 Maintenances Manual but no reference there to part numbers in the front axle section. GM seems to avoid part number in their Maintenance Manual whereas Ford seems to often quote them.

Cheers,

[rob love]

Sorry about the part number...I'll have to confirm tomorrow. It is likely the 3358 number you quoted and I hit one digit off.

It would seem as though Ford was the primary designer/supplier of the knuckles, brakes and hubs for the bulk of the Ford and Chevrolet CMPs. You will often find Ford's name on bearings, and Ford part numbers on castings.

There was a great deal of co-operation between the two during the design phase, as is documented in Blueprint for Victory by Bill Gregg. Some of it went the other way too. The Lynx armoured car had Chev brake system on one of the axles.

Remember that when it came to brake systems, companies like Bendix would provide the various models of braking systems, and companies like Marmon-Harrington would provide the various 4 wheel drive systems, Timken the axle systems, so there would have been some commonality just from the limited number of providers of engineering back then.

Often the Chevrolet parts manuals listed the FOrd part number as the primary part number, then after the description in parenthesis, would give the Chevrolet part number.

I am no fan of the chevys, so have to say that by putting Ford parts on a Chevy, you can only make things better.