changing transmission fluid

[surfivor]

 My corolla died at 260k or some such miles due to the transmission. Jiffy lube told me to change the fluid before 100k miles. The guy at the gas station said every 30k which I had never heard of that. There seems to be no specific guidelines. My current car is a Rav 4 and they will probably change the fluid today. I also have a tundra truck which is manual (stick shift) transmission, I don't know when I have  changed that

https://www.cartalk.com/content/service-your-car-14

Automatic: Service intervals for an automatic transmission vary from every 30,000 miles ... to never. The typical service interval is 60,000 to 100,000 miles. Changing it more often does no harm.

Manual: Most manufacturers recommend that manual transmission fluid be changed every 30,000 to 60,000 miles. Under heavy-duty use, some manufacturers suggest changing transmission fluid every 15,000 miles.

[Zef_66]

I have always changed my fluid every 25k - 30k miles for both my autos and manuals. The biggest point is that you are changing it. 30k, 50k, 60k, etc doesn't really matter. But the more often you do it, the better chance you have of your transmission lasting longer.

[Carl]

  Auto transmissions of today need to be changed according to how 'used' they are and often ,for my Toyota's,it is suggested at 50,000 miles though ATF fluid color and viscosity are looked at as a guide to use and abuse. The cost of fluid change is far less than the damage done over time and the level should be topped off in manual transmissions but rarely needs replacing.Abuse,heat,load...as in camper or trailer towing etc all factor into maintenance interval.You can't do this too often.

[alexlindsay]

I think it depends on how you do it. If you're just doing a pan drain and fill then 30k makes sense. If you're employing a method that gets every bit of the fluid out then maybe 100k is not too unreasonable. Probably also depends on the fluid used, a high quality full synthetic fluid will go further no doubt.

[Zef_66]

I think it depends on how you do it. If you're just doing a pan drain and fill then 30k makes sense. If you're employing a method that gets every bit of the fluid out then maybe 100k is not too unreasonable. Probably also depends on the fluid used, a high quality full synthetic fluid will go further no doubt.

In my opinion, 100k miles is asking a lot for even a synthetic transmission fluid. As Carl mentioned, monitoring the color and condition versus brand new fluid usually tells when it is time to change it.

[alexlindsay]

Fair, I'm not arguing for any particular change interval. Some manuals that I've seen called for 100k changes, some say never. I was only concerned about people properly executing on whatever OCI they planned on.

[CarbideAndIron]

We do 30-40k with our Duramax, synthetic fluid, and it deals with the abuse of towing, plus my wife's lead foot. Tranny still shifts great with around 170k on it now.
On my gas engine stuff, I have ran longer intervals, like 50k no problem. Only one had trans issues, but that was at 150k miles, plus the car ran 12.80's on drag radials. Basically I beat on that tranny good.
Both are just draining pan. But if you want to get it all out, pull the line off after refilling, have someone start and put it in gear, watch the color of the fluid pumping out of the line into your catch container. When the color goes from dark, to the new light color, you're good. Then just top it back off.

[Carl]

  While many may think little of transmission service ,I feel the fluids are the life of the vehicle and even replace brake fluid and radiator coolant on a schedule.

[machinisttx]

If it's a high mileage vehicle and maintenance hasn't been done, then there is a chance that the new fluid(with it's fresh detergents) can break up deposits and create more problems than it will solve. Otherwise, every 25-30k for an automatic. I need to change the fluid in the manual in my truck..but the recommended fluid is only available from either a GM or Chrysler dealer at something like $13 per quart. No exact replacement for that fluid is available anywhere else, so I haven't been in any hurry to get it done.

Carl brings up a good idea. Brake fluid is hygroscopic and needs to be changed infrequently. That's the reason it always says to only use brake fluid from a sealed container. Coolant becomes acidic and needs to be changed.

[Stwood]

I go bt color on automatics.
Standards, which I have 2 of, I ho-hum them. Mainly just ck to make sure they are full.
If I have a leak, then ck more often.
Brake fluid, I use silicon, which does not absorb water. Higher priced, yes. And does not mix with Dot3 or 4.