Transmission Oil Change on a M35A2 Deuce and a Half

Published on November 1, 2014
Duration: 8:46

This guide details a transmission oil change for an M35A2 Deuce and a Half military truck. It covers removing the transmission cover, identifying and draining the old GL-1 or GL-5 fluid, and refilling with 30 weight non-detergent motor oil, which is stated as the manufacturer's original specification. The process includes checking the fluid level by inserting a finger into the fill hole to the first knuckle and notes that the new oil may improve shifting, particularly into second gear.

Quick Summary

The M35A2 Deuce and a Half transmission was originally designed for 30 weight non-detergent motor oil. This type of oil is recommended for improved shifting, especially into second gear, and to enhance the transmission's longevity. To check the fluid level, insert your finger into the fill hole to the first knuckle; oil on your fingertip indicates the correct level.

Chapters

  1. 00:01Introduction & Overview
  2. 00:11Removing Transmission Cover
  3. 00:32Breather Inspection
  4. 00:51Locating Drain & Fill Plugs
  5. 01:12Transmission Drain Plug (9/16 Hex)
  6. 01:25Transmission Fill Plug (5/8 Square)
  7. 01:38Alternative Plug Types
  8. 01:58Draining Old Fluid
  9. 02:08Old Fluid Analysis
  10. 02:43New Oil Selection (30W Non-Detergent)
  11. 03:49Refilling Transmission
  12. 04:42Filling Process
  13. 05:06Checking Fluid Level
  14. 05:41Post-Service Expectations
  15. 05:58Test Drive
  16. 07:20Test Drive Results & Conclusion

Frequently Asked Questions

What type of oil is recommended for an M35A2 Deuce and a Half transmission?

The manufacturer originally specified 30 weight non-detergent motor oil for the Spicer transmission in the M35A2 Deuce and a Half. While military specifications later allowed for GL-5, using the non-detergent oil is suggested for better shifting and longevity.

How do you check the transmission fluid level on an M35A2?

To check the transmission fluid level on an M35A2, insert your finger into the fill hole until the first knuckle is at the edge of the threads. If there is oil on the end of your finger when you pull it out, the fluid level is correct.

What tools are needed for an M35A2 transmission oil change?

You will need a 7/16 inch socket or wrench for the cover bolts, a 9/16 inch hex socket for the drain plug, and a 5/8 inch square drive socket for the fill plug. A funnel and a container for old fluid are also necessary.

What are the potential benefits of using 30 weight non-detergent oil in an M35A2 transmission?

Using 30 weight non-detergent oil is believed to improve shifting, particularly into second gear, which is often stiff on these vehicles. It may also contribute to extending the overall lifespan of the transmission.

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