Transmission Fluid Question

That will vary greatly depending on the transmission model you have and the service category you operate in. Long haul road operations have a different service schedule then off-road or severe duty uses. Eaton Fuller manual transmissions have a different service interval then Volvo I-shift and so on.

Every major manufacturer has their service information posted online, google the model number of your transmission and look for the service manual. Here is the link to the manual for my last transmission, Eaton Fuller 13 speed RTLO14613b. http://partsmanuals.org/fullerservi...-RTLOF-14613B-transmission-service-manual.pdf

Also, since most won't follow the link here is a screen grab of the service interval for that transmission, notice the first trans oil change is at 10,000 miles which is a step almost nobody does. Doing the first drain on time removes all the break-in wear particles that happen with any new mechanical device.

 

Find out what trans you have, what type of fluid of you using and what type operation you are in and we can give you the right answer. Yearly or 30,000 miles is nonsense as most cases trans fluid is good to last years or several hundred thousand K.

 

Linehaul and synthetic is 5 years or 500,000 miles for oil and filter. Filter is optional for most models and only required for 13 or 18 speeds or engines with over 2050 FTLBS of torque.