Hello everyone,

This is my first post and my question is should I change my transmission fluid or just leave it. I have a 2002 4runner Sr5 w/ 3.4L 2wd. I bought the truck with 146k miles and now have 185k mi and I'm not sure about the service history of the tranny. I feel that overall the truck was well maintained and there are not any issues with the tranny at this point. I used my 4runner for boat towing last summer (3900lbs) and will be again this summer and want this runner to last. I contacted multiple dealerships and got multiple answers... 1) don't change it. 2) do a drain/fill. 3) Flush the whole thing. Can anyone help? Thanks in advance

Yes. I forget what the service recommendation is, but it is usually 25k or 35k and always shorter if you tow.


Your auto transmission is easily the most expensive and important part of your car, either equal to or right behind the engine. You would never
"not change your engine oil" for fear of hurting it.

It goes like this: Changing fluid on a good, healthy transmission will ONLY help it last longer. And 2nd, changing fluid will only hurt a already zombie transmission that is close to death. It may speed it up, but it didn't cause it.

You get a lot of people who fear changing their fluid because they know their transmission is dead and the only think keeping it going is the sheer grit of metal shavings in the fluid. They know it is bad.. that transmission slips horribly and gives off all kinds of warnings. In this situation, if you are broke and cannot afford at the moment an expensive tranny repair.. sure, drive on.


Hope that helps.

#2

I like to drain and fill. You are only changing 30% of the fluid so it won't affect much either good or bad. It's just matainance. Do it again in 6 months or next year.

Doing nothing is not a good idea and people have concerns about the flush. I personally think you'd be fine with a flush too. However, you can't argue with a simple drain and fill, it's just a good safe idea.

I use Mobil 1 and have nearly 100% synthetic in my trans. You can use a synthetic or just get regular Dextron III.

You do not need to drop the pan or mess with the filter at all.

Do a drain and fill a couple of weekends in a row, that will get the majority of the old fluid out, and you should be good to go. Get a new crush washer for the drain plug on the tranny.

Yea. Second that. It sounds very healthy and I wouldn't worry about a fluid exchange or even a flush, but if you really ARE worried; then do a few drain and fills.

Just make sure you pop the pan down and take a look and replace the filter with OEM. There is a thread in here about the crappy quality of NON OEM filters. So, go REAL and get one from Toyota.

I wouldn't worry about the filter as much, it is a good idea but these transmissions don't have "filters". They have a metal screen.

If I were you I would do drain and fills at every oil change until the ATF is nice and deep red then just do drain a fills every other, or every third oil change. This is how I treat my tranny and she treats me pretty well in return.

side note: 270k faithful miles and my tranny doesn't miss a beat.

Excellent! I can't thank you all enough for the input, you guys are great. I'm going to go with a drain and fill and change the rear diff. fluid in the near future.

Change the front diff and transfer case fluid while you're at it, and always remember to loosen the FILL plug before the drain plug. And grease your driveshaft.

The OP is only 2wd Ian... So no transfer case or front diff

Which type of ATF do you guys recommend? Also, how often does the crush washer need replaced and where to get one? Only at Toyota dealer? I've seen crush washers at auto parts stores but question the quality. I need to start draining and filling just as the OP and want to get what's best for my truck. Thanks.

I must have missed that, lol!

The crush washers are cheap, buy a dozen and have them on hand forever, costs you a couple bucks. Replace them anytime you remove the drain plug, they are designed to be single use, quality is not a concern IMO. Tranny fluid is Dextron III for these trucks I believe, but your tranny dipstick will say on it as well.

no greasing of the drive shaft either for the 2wd'ers...unless they rebuilt at some point with greasable u joints.

Well then...disregard much of what I've said here then, lol. Thanks for keeping me on my toes guys!

Will forgive you, Ian. But just this time. More mistakes like this and I think will have to bring down the BANHAMMER.

Seriously though, it makes no ****ing sense not to have greasable u joints. So, I don't know why you would have known that particular tidbit.

Ya, no kidding! I have no personal experience with 2wd or any of the gas engines for these things, but I like to help out where I can.