Transmission Fluid

After changing my rear differential oil yesterday, I realized my transmission fluid most likely has never been changed. I've read through some previous forums to find that the fluid doesn't need to be changed till 100k miles? I'm not really a grease monkey, but that just doesn't sound right to me. I'm currently approaching 104k miles, so what should I do? Local mechanics tell me not to open it due to the new detergents which can cause slippage. Who here has left their transmission alone and haven't ran into any issues? I don't tow or haul anything above 100 pounds. My mother's 98 4Runner has 214,000 miles and the tranny has never been touched. Any comments are appreciated!

 

What's regular intervals for transmission fluid? I'm having a hard time finding anything in the manual about this.

 

There are 2 schools of thought:

- If you don't tow or engage in things that kill fluid and trannies(I hear plowing snow is one of them); then don't change 'til 100K. There are people on this forum who have gone 150K-200K w/o a transmission fluid change. Your moms vehicle is a good example of fluid longevity.

- Change every 20K-30K like we did back when, regardless of how the vehicle is used.

To me it's all about where your comfort level is and how you want to spend your spare time and money.

If I were the type that bought a new vehicle every 100K, I wouldn't change anything but the oil/filter, air filter, cabin filter, wiper blades and tires.

 

I'm more of a "If part X fails and I didn't do my best to maintain it, I'm going to be pissed at myself"

Drain/fill the fluid is a pretty easy job and helps me sleep better at night knowing I've done my part. If "part X" still fails at least I'll know I've done my part and it was going to fail anyways.

According to carfax my tranny fluid was "flushed" long before 100k by a Toyota dealership.

 

I called around to various transmission shops around and I got varying quotes on transmission fluid flush. One quote was as low as $150 vs the dealers price of $280. One dealer specifically asked if I do any towing. I don't care if I don't do any towing, this is my truck with 145k+ miles and I want to replace the old fluid with new because I have no service receipts from the previous owner that it was ever flushed. I've heard things like it never needs to be changed. That sounds like BS regardless of the kind of use your subjecting your vehicle to. End of the drivetrain warranty seems like a good time to get flushed and then a yearly drain and fill thereafter with a flush every 50k miles. Anyways, $150 sounds like a good deal but its a big difference from the dealer price, so I'm wary. It is a transmission shop so I assume they would have all the tools compared to a quick lube shop or mom and pop garage? Stopped by Firestone and they said they won't touch it because its a sealed transmission yet Pep Boys quoted me $200 to do it. Don't understand why one chain shop will do it but another won't. Has anyone had their transmission flushed from either type of shop? Do they really do a flush or just drain and fill? If they do a flush do they also take off the pan and clean/replace the filter?

 

I just had my transmission oil replaced at 85,000 by a local trans shop. He recommended changing it every 30,000 miles. He said the car manufacturers post these ridiculous service intervals to look better to the EPA.

 

Be wary of a flush at tranny shop. I have heard they could have any kind of fluid in machine not necessarily WS. So you could end up with a mix. Not sure I would let Pep Boys touch it.