Scotty, I have a 1998 4Runner with just over 210,00 miles on it. It has been an absolute tank! I have never had to do anything to it other than routine maintenance and replace a couple of alternators. I looked into a 4th or 5th Gen and decided that financing a vehicle for upwards of $30,000. was not something I am interested in, so I would rather put some real money back into old reliable. I see a couple of issues in the reliability department that I may want to work on: first, the transmission fluid is looking a bit black. The transmission has never slipped or dripped, but the color is concerning. I have been told that flushing an automatic transmission is asking for trouble, what should I do to properly get the most life possible out of the tranny? Also, I have the same question for the engine? It too, has never missed or had an issue, but I worry about my reliability as I plan on using the runner as my daily driver including frequent trips into the Colorado back-country. Thank you!
Firstly, you want to drain and fill the transmission and replace the filter. Never flush it out as that creates a lot of easily avoided issues.
As for the motor, just follow the maintenance every 5k miles and you should be ok. Every engine is different and has a different life span. Maintenance is the key to getting the most out of any machine. Cars are no different.
Stick to your service schedule in your owner’s manual religiously & that vehicle should last forever.
Has your transmission fluid ever been changed before? If not, I’d only replace it if it didn't smell burnt or if there was no debris in the fluid. Otherwise, I’d just leave it alone.
Never flush engine or transmission fluid, unless it was your last resort to get the vehicle moving.
