In the process of restoring my father's 1930 Model A Pickup that was sold out of the family when i was 10 (1976) and recently reacquired this year
I have the cab and bed off the frame and something interesting is installed on this vehicle. So in the cab area mounted on the inside of the firewall is what looks like a chamber with 3 rubber hoses leading out of it along with a pull lever know that was attached to the steering column. Now 2 of the hoses ran from the coupling chamber back to a device on the rear axle right hand side. The other hose runs through the firewall and attaches to a copper tube into the intake manifold. Now my buddy says it appears to be some sort of vacuum setup but we are not sure what it is controlling in the rear end. Could this be some sort of limited differential slip setup or lockout? Unfortunately i started taking the pickup apart before checking out the function of that setup.
Bill