How To: Restoration of Ford M8 armoured car US Ordnance number 7373

[motto (RIP)]

Hi Darryl
In post 308 you asked if anybody knew the difference between -2 and -3 UN threads.
I only noticed the question today and had a look in a copy of Machinery's Handbook 1971
To put it simply the differences are to do with production and not maintenance. The numbers designate the class of thread in relation to manufacturing tolerances and should be compatible.
In relation to the axle flange collets, I can't guarantee that they are the same but the Studebaker US6 used those which probably means they were also used on the split diff GMC 6x6. Ross Prince may have them.

Dave

According to the GMC SNL, collets are used on the rear axle drive flanges. They are referred to as dowels and the Timken Detroit part number is TD-1246-X-232 General Motors part Number is GM-2124231

[Big D]

Hi John

Thanks for that. I will check them out and let you know if I get stuck.

[Big D]

Hi Dave

Thanks for that. That is interesting. The wheel nuts should theoretically fit then, with them being the same thread and pitch. Why they won’t, is a mystery!

I will keep searching....

[Alastair Thomas]

If you are sure that the threads are the same nut=to-stud then you could try a trick I stumbled on with a car restoration.
I could not get the track rod end nut to run sweetly on to the tread even after I had run the correct die onto the thread and tap into the nut so in desperation I mounted the end vertically in the vice (soft jaws of course) put the nut on one thread and then filled it with Brasso. With very little working backwards and forwards the nut then ran on using fingers alone. I cannot explain what happened as the threads were bright and clean beforehand. I just assume that the mild abrasive in the Brasso removed something I could not see.

Alastair
F60S

[Big D]

Hi Alastair,

Thanks for that. Good idea. After your post I recall someone who did a similar thing with some valve grinding paste. That might yet be worth a go.

[David Dunlop]

Hi Darryl.

I went back to review your first photo post. The old girl’s come a long way from what you started with. She’s looking quite proud now back on her wheels, for the first time in however many years!

Nice that you have her original US Army ID. Be interesting one day if you were able to fill in the history gap from production to takeover by the Italian Army.

David

[Big D]

Hi David

Thanks for that. Yes, I looked back myself and it has been a bit over three years since I started this thread. That's a lot of posts! It is very nice seeing it on wheels, and it would be great to learn a bit more about its history. Hopefully the historical data will keep on filtering out.

[colin jones]

Darryl, what can anyone say except "SUPERB" you attention to detail and workmanship is second to none and you will end up with a vehicle that will last way past you and me but will always have your name on it. They are such a cool looking machine. Are you going to get you 37 gas firing as that would be the cherry on top.
Great work.
Colin.