Hello!

This is my first time posting, although I've been coming to this forum for a little while to get some insight.

I have a question, that hopefully some of the more mechanic savvy folks can maybe answer...

I just purchased a 2006 4Runner that has about 190k miles on it. I normally wouldn't purchase a car with that many miles, but the body is mint and the service history on the carfax is impeccable. Whoever owned it before me literally went to the dealer for everything and had every required service needed.

Well, the question I have, is when I went to get my first oil change at the dealer, the Service Advisor mentioned that there was no record of a Transmission Fluid Change, nor was there any record of the 4 wheel drive fluid being changed either.

Now I'm not sure if this previous owner did or didn't do these things, however, let's assume neither of these were ever done...am I putting myself at any risk by changing either of these two fluids now at 190k miles??

I asked the Service Advisor that same question and she brushed them off like I was living in the stone ages, but I just wanted to make sure!

Any responses are totally appreciated! Thanks!

Hi Paul, welcome.

I assume the 4wd fluids you're referring to are the differential and transfer case fluids. If so, no danger at all in changing them so long as they're refilled with an appropriate gear fluid. It's pretty easy to do if you're familiar with working on cars and don't mind getting a little gear oil on you. Here's a writeup just in case you want to see what's involved:

http://www.toyota-4runner.org/mainte...-included.html

As for the transmission, it's not quite as easy to DIY. There are two methods - flush and drain/fill. The flush method uses a machine to forcefully push transmission fluid out. The benefit is that you exchange all the fluid in a timely manor. The downside is that you run the risk of stirring up some particles from the pan of your transmission that could get back into the transmission and cause a problem. For that reason I think most people on this site would recommend the drain/fill method. The downside to this method is that you have to do multiple drain/fill cycles to get most of the fluid exchanged. And even then you'll probably never actually get all the old out, it just becomes very diluted because it's mixed with the new. You can read more about it here.

Transmission Service: Drain & Fill or Machine Flush?

BTW, if the 4Runner was dealer serviced you should go register the VIN at the Toyota Owners website. It'll have more detail on the services performed than the Carfax shows.

Jimithing, thanks for your response!

I guess my question was more related to whether or not I could cause damage to either the transmission or 4wd on the vehicle, by replacing those fluids now, assuming they've never been replaced in the past, since the vehicle now has 190k miles.

Thanks!

4wd - no
Transmission - small possibility if they do a flush. no if they do a drain/fill.

Hey Paul,
I just got my 2003 4runner, it belonged to my mother before she passed away. it sat in a garage for 2years before i got it. She too had it serviced at Toyota dealers only, she had never done the tranny, diff or transfer case fluids. I could not get an appointment with the dealer for the oil change so i went to a quickie lube place and had the oil and all other fluids changed. That was a week ago. So far all is good and the truck seems to feel a little nicer, this could be in my head.
I just hit 125,000 miles the other day. I am no expert but i think new fluid is usually the best bet when in doubt.
Enjoy your new ride, i know i love mine.

I dont think you will have issues with a drain and fill on the tranny. Don't let them talk you into flushing.

Also check into the last time the coolant was changed. The fluid might test ok to protect your engine from overheating or freezing but i always worry about if your fluid turns acidic, and that will eat a hole in your radiator.

Thanks Ridefast...I've got an appointment tomorrow actually to do the differential fluids and they are going to check the trans fluid, although at 190k miles I can't see why they won't want to replace.

I will ask about the coolant as well.

How often should I have the coolant fluid changed?

One of the first things I did when I picked up my used '06 4Runner with 165K miles was to change every gasket I could reasonably manage along with every fluid I could think of.

List includes:
1) Engine (Crank) Oil (Mobil 1 5W30 Synthetic)
2) Grease Driveshaft Zerks (Mobil 1 Grease, Pink/Red in color)
3) Front Differential (Mobil 1 75W90 w/ Limited Slip Additive)
4) Transfer Case (Same as above)
5) Rear Differential (Same as above)
6) Transmission Fluid (OEM Toyota WS ATF)

note: I drained and filled 4 times a couple weeks apart. Resulted in 7 to 8 quarts being swapped out, ~2 quarts at a time)

7) Coolant (OEM Toyota Super Long Life Coolant)

note: I did this once upon receiving the car. I just drained from the radiator which resulted in 1 gallon being swapped out. Good enough for me

Other maintenance items I did just to start at ground zero:

1) Spark Plugs (OEM Toyota)
2) Air Filter (OEM Toyota)
3) MAF Clean
4) Throttle Body Clean
5) Transmission Fluid (Valve Body) Filter Change [A little extensive]
6) Valve Cover Gaskets (L/R) Change [A little more extensive]
7) Chevron Techron Fuel System Cleaner
8) PCV Valve Change
9) Bilstein 5100 Struts/Shocks

I did everything above (except the front struts) in an apartment garage with minimal tools and of course the aid of this T4R.org. Did I need to do absolutely all of the above? Probably not, but the thing ran great on the test drive and runs even smoother now.

To answer your question, Toyota suggests our trucks have the coolant swapped out at the 100K mile mark, and then every 50K miles afterwards.

Just be careful they are going to want to do quite a lot to your truck with your mileage. A lot of this you are going in for is super easy to perform with basic tools.
Our long life orange coolant should last 150k miles or so. You can get test strips from the auto parts store ( under $10) and do this yourself.
Some test kits won't work with orange coolant so just read the label.

Or don't bother with the kit and just drain and fill. That's what I would do.

Thanks for taking the time to post this! I actually called a few dealers today and it's a little ridiculous as far as the range in prices you'll see amongst these dealers for the same services...ironically and unfortunately, the most expensive by far is down the street for me.

Thanks for the insight!