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Installation Guide: PA B-18, B-24, B-31 Gear Box Assembly To Machine

Updated: Jan 3

This is a step by step guide for installing your PA General Pump B-18, B-24, and B-31 Gear Box Assembly on your machine. This will work for 1" and 1-1/8th" Shaft Power Units.

Step 1: Check Key-way Alignment on motor shaft and gear box shaft. Everything facing upward is easier and shown in this installation guide.

Step 2: Lubricate The Gear Box Interior Shaft.

  • Permatex or High Temp Lube. Carefully lubricate the interior shaft of the gear box with high temp lube or anti-seize.

  • Apply Lubrication: Remember a little goes a long way!

  • Inspect: Inspect to ensure a proper amount of lubrication is applied. Not too much, not too little.

Step 3: Key Way Alignment (VERY IMPORTANT)

  • Shaft Key should be installed 1/8th" away from the end of the motor shaft.

Step 4: Install The Gear Box on the Engine Shaft

  • Hold Key in place; With a finger, hold the key in place while simultaneously,installing the gear box assembly. Take extreme caution to make sure the key stays in place and is aligned properly.

  • Little to No Resistance; The Gear Box should slide on with little to no resistance. If the pump gets caught up or stops while sliding on, most likely the key has shifted. Take if off and try again.

  • Flush Mount; The Gear box should be touching flush with the face of the power unit. Everything should move smooth and easy on the engine shaft.

Step 5: Install Compression Washers to 9/16th Hex Bolts

  • Properly install the compression washers to the 4 x 9/16th Hex Bolts.

  • The Crown of the washer should be facing the bolt head. (CONVEX UP)


Step 6: Install Hex Bolts and Brash Washers Between Gear Box.

Hand Tighten all 4 Hex Bolts:

  • Slightly back the gear box off the shaft to install spacers, washers, and bolts.

  • Hand tighten all 4 hex bolts afterwards.

  • *If using a pump support bracket on your pump, install that during this step.

Gap Is Normal:

  • The Gap when tightened should look like this. Everything on evenly and smooth.

Torque Hex Bolts:

  • Torque the hex bolts down (NO THREAD LOCK) to 40nm (22 in.lbs.)

  • *Over tightening can result in hex bolt snapping off inside the motor or damage to the gear box.

After this step.


You have successfully installed your PA Gear Box Assembly!

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1 Comment

This tutorial is extremely well written and illustrated. Fantastic bit of information to those who need it.

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