About Us


Randolph Gear Drive
Product of Randolph Manufacturing Company
1110 North Avenue T / Lubbock, TX 79415
(806) 765-5583 / (888) 726-4327
FAX (806) 765-7735

The Original Fan-Cooled Gear Drive

Randolph Right Angle Dual Drive


This drive may be used as a Double Engine Drive or as a Combination Drive using a horizontal electric motor and engine.  When used ass a Combination Drive, over-running clutches should be provided fro disengaging the idle driver.  When used as a Dual Drive with the tow input loads equal, the transmission capacity is 150% of the standard rating of the G40 through G200A only.  Contact the factory for the maximum rating of the F250 through G400.

Fan Cooled Gear Drives
Our air cooled heat exchanger was designed to meet a need in areas where cooling water and ambient temperatures create a problem when cooling coils were the only way to cool the oil in a gear drive.  The Models M40 thru M80 and G40 thru G200A, with fan cooling only, should require no other means of cooling.  The Models M100, M200 and G250 thru F1500 having cooling coils included and must be connected for any extended use or high ambient conditions.  All propeller pump drives require no water cooling.  Oil temperatures of 200 F (93C) are not dangerous.  Best temperatures would range between 135° F (57° C) and 180° F (82° C).

Gear Drive Construction
High tensile strength castings are used throughout for rigidity.  An outstanding feature of Randolph Gear Drive is anti-friction ball or taper bearings, which are engineered for long life and rugged service.  There is a large oil level sight gauge glass on all drivers.  The air cooled heat exchanger, for control of oil temperature rise, eliminates clogged cooling coils, expensive cooling water hook-ups, and the use of undesirable types of cooling water.  Alloy steel spiral bevel gears and pinions are case hardened and lapped in pairs to insure perfect contact and long life.  Positive type non-reverse available on all models.  Pressure type lubrication systems on all drives.  (Lubrication systems are available for very low speed applications upon request). The permissible loading varies with the speed.  In borderline cases, a maximum of 10% overloading is permitted before the warranty is voided. This overloading condition should be used with the knowledge that a corresponding reduction of 20% to 30% in bearing life may be expected.

Randolph Gear Drive Efficiencies
Randolph Manufacturing Company recommends a design value o f96% efficiency in all applications.  The actual efficiency will depend on operating loads, speeds, temperature and other parameters.  The 96% value can be taken as a minimum value throughout the life of the unit.  If unusual conditions exist, consult the factory for your specific application.

Limited Warranty
The Randolph Right Angle Gear Drive is warranted as provided hereafter, for a period of one (1) year from the date of installation, provided installation is not more than three (3) months after date of sale, against defects in workmanship, design and material when operated under normal service at rated capacity, subject to the following conditions:

Within the above stated warranty period, the manufacturer, Randolph Manufacturing Company, 1110 N. Avenue T, Lubbock, Texas 79415, will replace defective parts and all transportation costs paid by the customer, at manufacturer’s location at 1110 N. Avenue T, Lubbock, Texas 79415;

The replacement of defective parts and transportation costs as set forth in Paragraph 1 above shall be buyer’s and user’s sole and exclusive remedy for any and all damages or loss arising out of or caused by alleged negligence on the part of manufacturer or alleged defects in workmanship, design, warning, or material;

This limited warranty shall not apply to drives which have been the subject of abuse, neglect, accidents, misuse, improper installation, overloading rated horsepower of the drive or overloading rated capacity of thrust bearing (in this regard the thrust capacity of the drives should be verified by the pump manufacturer with those whose equipment the drive is used);

This limited warranty shall not apply to bearings, accessories, machinery component parts or other articles of merchandise manufactured by persons or other entities other than Randolph Manufacturing Company.

This limited warranty is given in lieu of all others, and Randolph Manufacturing Company Hereby disclaims all others warranties of any kind, including implied warranties of merchantability, implied warranties of fitness and implied warranties of fitness for a particular purpose:

This limited warranty and the exclusive remedy provided herein to buyer and user shall be construed under the laws of the state of Texas, United States of America as they exist at the time claim is made under the limited warranty.