Preston Cannon

I will probably be blowing up this forum as im very excited to start working on my new-to-me truck and will have a lot of questions.

The first question I have is, should I change the tranny fluid? The truck has 270k on it and I want to do whatever preventive maintenance to it so it can last me a while, and i especially want to avoid transmission issues, because my Jeep's tranny was horrid...

Anyways, I've heard many times that changing fluid if it hasnt been changed in a long time can cause a transmission to fail prematurely but i've also heard that it would have failed despite the changing of the fluid. The ATF is a reddish brown so it seems that its not too old, and doesnt smell burnt or anything. Would it be safe to change it considering it seems it has been changed?

Same question with the differential, is it okay to change it if it hasnt been changed in a period of time? I havent checked that fluid at all but the truck has been very well taken care of.

thanks and sorry for all the questions!

Preston Cannon

Also, its a 2003 double cab TRD offroad package, 2WD, automatic, 5VZ-FE v6. It does have the differential lock.

old87yota

Sometimes changing the fluid is a toss up when it has not been serviced in a long time.

I found a good YouTube video that might help you in your decision:


I changed my original differential fluid in my 1987 truck last fall and so far have no ill effects for having the fluid in there for nearly 29 years, although it looked pretty old. I have yet to replace my automatic transmission fluid.

Preston Cannon

thank you very much! I am not sure how I have not found that video because I watch a lot of Chris Fix's videos. I have decided to do a fluid change since the fluid seems to be in relative good condition and is not black and burnt. I am also going to go ahead and change my differential fluid, unless anyone has any objection?

Another question, what fluid is good to use with the transmission and the rear differential? Again, I do have lockers