303M HydraMatic rebuild

[rustystud]

I've been receiving a little interest in the "front servo" upgrade I posted about. I did say it is a drop in installation, but I need to clarify it a bit. You will need to cut off the pipe nut which normally threads into the servo. The later model servos did not use this nut. They just had a straight pipe go into the servo.
This is a picture of the two pipes.
So just cut off the flare end and your Golden !

You will also need to plug this hole with a 1/8" pipe plug. Use a 21/64" drill bit and drill down 1/2" . Then tap out with a 1/8" NPT tap.

I installed a stainless steel 1/8" plug here.

 

[rustystud]

Had a talk with the gasket maker "Gardico" and we're looking at two to three weeks out. Went to the machine shop also. He is extremely backed-up and is looking at maybe three weeks before he can even start on my projects.
I have a few things left to tear down and clean-up. One being the rear oil pump. Actually, I have seven pumps to tear down and clean-up. Also, about seven rear servo's and three front servo's.
I'll post about the rear pump, and anything that pops up during the servo clean-ups.
I still have three more complete civilian HydraMatics to tear down also. I'll post anything interesting.
Other than that, I probably will not be posting much for about a month.

 

[rustystud]

I've been getting ready to visit "plowboy" up in Canada and part of getting ready was rebuilding a Front servo unit for Dave.
I noticed something I never thought to check before. The 303M front servo has a smaller piston then the later (1953 on) civilian HydraMatics . This piston in the civilian models gives you an extra 0.120" larger piston. That's translates into more band holding power. So going to this later style servo not only gives you the "engine braking" ability in third gear, but also gives you better holding power in all the gears with the front band applied.
Also, the 303M piston rod has a hole drilled through it for no reason I can think of. The civilian model has a stronger solid rod.

 

[DUUANE]

Well you should get some credit as you sold me one of those 303M transmissions.
Now If I could only find a few more. Do you have any leads ?

I know where a couple of trucks are.. but seems like they are pretty much the usual runners with no brakes, or no reverse or both. Ill ask Rick at Milspec Hydraulics if he has any spares he can let go.

 

[rustystud]

I know where a couple of trucks are.. but seems like they are pretty much the usual runners with no brakes, or no reverse or both. Ill ask Rick at Milspec Hydraulics if he has any spares he can let go.

Thanks !