I am the proud owner of a 2004 Toyota TRD Tacoma PreRunner V6 Automatic. I purchased the truck off of the showroom floor. I have gone through my owner's manual several times and have noticed that it does not indicate when to do a transmission flush. Currently, the truck has just 42,000 miles on the odometer.
By the way, I do not tow with this truck. I use it for driving to and from work 5 days a week with a 7 mile commute each way. I have not had a single problem out of the transmission and would like to keep it that way.
Should I flush the transmission now, or wait? Some local "experts" recommend a flush every 35,000 miles. Is it really necessary to flush that frequently? What should I do? Lastly, the same situation goes for the rear differential. The manual only says to check the level. Is it time to flush the rear diff too? If so, is there anything special I need to be aware of with respect to additives since I have the lockable rear diff?
You should be a proud owner; TRD Tacoma is a strong truck.
Maintenance can be confusing. Toyota's normal maintenance schedule for your pickup implies that replacement of automatic transmission and rear axle fluids (differential) are unnecessary under normal driving conditions. However, the severe maintenance schedule shows every 60,000 miles on the transmission and every 15,000 on the axle -- severe meaning towing, dirty roads, short trips and stuff like that.
My personal opinion -- if you love your truck and plan on keeping it for years to come -- is to abide by the severe schedule regardless of driving conditions. Although 15k miles on the rear axle seems a bit much, 30k should be sufficient.
Always be sure to use the specified fluids. It should be Toyota Genuine ATF Type T- IV in the transmission, and SAE 90 hypoid gear oil for the rear axle in temperatures above zero degrees. Your locking differential uses an electrically driven actuator at low speeds. There are no limited-slip clutches so an additive is not required. Double check with the Toyota dealer on fluid type and capacities for your specific PreRunner, and be sure to use only Toyota brand automatic transmission fluid.