165K and fluid is still good, What to do ?
 

I just turned 165 k on my 98 4.6 auto. I bought the truck used with 32k on it 5 years ago and the fluid was changed then. I have always checked the tranny fluid and it has always been red, But now it's starting to turn a little brown.Still shifts fine and doesn't slip. I don't tow and rarley haul anything heavy. My ? is should I do anything to it?.

You should change it NOW! Once it starts turning brown it's really worn out.
It should have been changed a long time ago. Fluid shears and wears out, and it will still look nice and red even though it's not doing the job as well as new fluid.
Change all the fluid, not just what's in the pan. Either a flush or drain the pan and converter.

I agree...I would have changed mine multiple times in that mileage. Funny tidbit...there was a member here a few years back that claimed to be a transmission tech. He suggested never changing transmission fluid. It didn't go over well. :p

I will take everyone's advice and change it. Should I go synthetic ?
Since I haven't changed it in 133k mile, Am I going to cause any problems putting in clean fluid.

Your problems will be from "not changing it". You'll be better off with even the cheapest of ATFs. If you have the money, the synthetic is a better product. I generally use synthetic, but if I had 165K and one fluid change, I would question how much life is left in it and just use the cheap stuff...personal opinion.

Now I'm worried, I also was told not to change the tranny fluid by a transmission mechanic until it started to turn brown. As of right now the truck runs and shifts great.

That's because he wants to get paid to fix it. Once the fluid is turning brown it's too worn out to properly lubricate the transmission. Running without good lubrication isn't good for a long life for your transmission!

Dont worry your transmission is not ruined. You deffinatly need to get it flushed though.

That's the perfect sign to never use this guy. No decent transmission tech would recommend this. Don't worry, just change it. ATF degenerates and transmission filters get dirty.

Will do guy's. This was told to me about 4 years ago by a tranny mechanic that is a friend of a friend that I have known for 20 +years. If he's just wanted to repair it he's been waiting awhile LOL

Just FYI, the service interval for changing the auto trans fluid is every 30k miles.....

I would not do a "flush" however.... I would just have them drop the pan and drain the torque converter. Replace filter and fill with fresh fluid......

I have my pan dropped each year and serviced (~20k miles) and drain the TC every other year.

I do tow and haul stuff and the fluid is always clear and red when it's serviced...... Fluid is a lot cheaper then repairing!!

Good luck!!

Mitch

Yeah, well um..... Yeah.