WINDOW GP-SLIDING 2147245 - Caterpillar

Poppet Valve Designs
Fifty-six 9N4115 Valve - 9N4116 Piston units are used in the transmission. Fifty-three are used in the 9N4117 Plate and Valve Assembly and three are used in the transmission ratio selector control group. See Illustrations 3 and 4.
Also in the 9N4117 Plate and Valve Assembly, a 9N4120 Valve and a 9N4118 Valve are used together in the air pressure regulator for the outout clutch.
The original poppet valve-piston unit in the 7155 Truck Transmission was made up of a 9N2684 Valve and a 9N1567 Piston. See "A" in Illustration 1. The piston was press fit on the stem of the poppet valve. It was possible for the piston to move on the stem, so the same parts were then press fit and staked (fastened by distortion of the metal with a punch).
Next, the 9N4098 Valve and the 9N4100 Piston were released. The stem of the poppet has a smaller diameter end and a shoulder. The piston fit on the stem, against the shoulder. The end of the stem was peened (bent) to fasten the piston to the poppet valve. See "B" in Illustration 1.
The new 9N4115 Valve has a larger diameter end on the stem, but it still has a shoulder. The end of the stem has an opening, similar to a tube-type rivet. The new 9N4116 Piston is installed on the stem, against the shoulder. A punch is used in the opening in the stem for expansion of the stem to fasten the piston to the poppet valve. The result is a stronger poppet valve - piston connection. See "C" in Illustration 1.
Illustration 1. The three poppet valve-piston units.The pressure regulator originally had a 9N2688 Valve on the end of the stem on a 9N2684 Valve. See "A" in Illustration 2. It was some times possible for the 9N2688 Valve to come off the stem.
When the 9N4098 Valve was released, the 9N4113 Valve was fastened to its stem with a 1L5316 Pin. See "B" in Illustration 2.
The new 9N4120 Valve has a longer stem than the earlier 9N4098 Valve, and its stem does not have a shoulder. The new 9N4118 Valve is pressed on the stem and fastened with a 1L5316 Pin. See "C" in Illustration 2. The result, again, is a stronger poppet valve to poppet valve connection.
Illustration 2. The three double poppet valve units.
Illustration 3. Location of the valves in the 9N4117 Plate and Valve Assembly.Installation Of The Poppet Valves And Pistons
Use of the Starrett No. 18-B Automatic Center Punch permits easy installation of the 9N4116 Piston on the 9N4115 Valve. See Illustration 5. Correct use of the spring-operated punch gives even expansion of the stem without damage to the piston. See Illustration 6.
Illustration 4. Location of the valves in the 9N1803 Transmission Ratio Selector Control Group.
Illustration 5. The Starrett No. 18-B Automatic Center Punch.
Illustration 6. Installation of a piston on a poppet valve.A replacement point, Part No. 2948, also is available. For the name of the nearest dealer and/or repair center, write or