TM 5-3810-300-24 & P2
The valve contains a relief valve that senses system pressure. If the pressure within the system exceeds 1500 PSI the
relief valve cracks and a pressure difference is created across the main control spool in the valve. The pressure
difference moves the spool, and a passage back to the power steering reservoir is opened. Excess fluid passes to the
reservoir.
Single Reduction Hypoid-Drive Unit. (Illus. 4-14).
Front-mounted Single Reduction Through Drive Type Drive Units with a two-gear transfer train built by Rockwell-
Standard incorporate hypoid reduction gears and bevel type gears in the inter-axle differential assembly. This unit differs
from other Rockwell-Standard front-mounted through' drive type drive units by the omission of an idler shaft and the
corresponding gear within the transfer gear train. Correct rotation of the hypoid reduction gears is accomplished in the
de-sign of the unit by simply cutting both gear and pinion with the opposite (R.H.) spiral angel and mounting the gear on
the opposite side of the pinion as compared to other through drive type drive units.
The input shaft is mounted on two ball bearings mounted in the single-piece carrier and cap assembly. The through-shaft
is splined to the rear of the inter-axle differential assembly and is supported by a ball bearing in a rear bearing cage
located in the housing.
An air operated axle lockout valve is in the air system. The valve when actuated to the lockout position from the Carrier
Cab allows air flow to an inter-axle differential shift unit. The air pressure shifts a sliding dog clutch collar on the input
shaft. The dog clutch engages corresponding teeth on the forward portion of the input transfer drive gear. With the inter-
axle differential lock up, both axles are forced to turn at the same speed regardless of slippage on one axle.
Single Reduction Drive Unit. (Illus. 4-15).
The Rockwell-Standard Single-Reduction Final Drive employs a heavy duty spiral bevel or hypoid pinion and gear. The
differential and gear assembly is mounted on tapered roller bearings. The straddle mounted pinion has two tapered roller
bearings in front of the pinion teeth which take the forward and reverse thrust and a third bearing behind the piston teeth
to carry the radial load.
Single-Reduction Final Drives are available in a wide range of gear ratios and sizes to cover most operating conditions.
Universal Joints and Drive Shafts. (Illus. 4-16).
To transmit required loads, the drive shaft must possess high strength. Forged steel, or high strength cast yokes are
generally used to provide necessary strength and the rigidity required to maintain bearing alignment under torque loads
and during high speed operation. Special high-strength tubing is used to provide maximum torque carrying capacity at
minimum practical weight. This tubing must be securely welded to its end members, to provide the necessary torque
capacity.
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