Engine/Transmission (1998.5 - 2002) When to Change transmission Fluid on Auto?

[The Sequel]

I know what the manual says about schedule A and schedule B, but I'd like to know how some of you in similar situations do it and how long your transmission has lasted. Weather here in the desert is obviously very hot and about 25% of my miles so far have been pulling a 6500-7000# travel trailer. A large part of the towing miles are in the mountains. I changed it the first time at about 30,000 when I had the Maghytech double deep pan installed. I'm using Quaker State ATF+3. I've been thinking about just draining it every 15,000 and doing the filter every 30,000. Since I've got the Maghytech it's easy to just drain and refill. I know dropping the pan and doing the filter wouldn't be that much work, but I'm trying to do it as quickly as possible without going overboard. What do you all think?

 

[ralphr]

changed mine at about 35K used amsoil, (no I am not affiliated with them in any way!), big difference in shifting, if I had transmission temp gauge bet it would be a lot cooler with the amsoil. plan on doing mine again at 70K, (filter and fluid). with you heavy towing and with the mag hytec prehaps the 15 K fluid change would be a good idea, expensive if using synthetic though.

 

[The Sequel]

Surely more of you have an opinion on this. Anyone else?

 

[Koa Man]

This chart should answer most of your questions. Since I tow or carry heavy daily, I change my transmission fluid every other oil change, which comes out to about every 6 to 7K miles.



Tech Tip Corner

Transmission Fluid





Automatic Transmission Fluid Oxidation

Automatic transmission fluid will provide 100,000 miles of service before oxidation occurs under normal operating temperatures of about 170°F. Above normal operating temperatures, the oxidation rate doubles (useful life of fluid is cut in half) with each 20° increase in temperature.



The approximate life expectancy at various temperatures is as follows:





175°F 100,000 miles

195°F 50,000 miles

212°F 25,000 miles

235°F 12,000 miles

255°F 6,250 miles

275°F 3,000 miles

295°F 1,500 miles

315°F 750 miles

335°F 325 miles

355°F 160 miles

375°F 80 miles

390°F 40 miles

415°F Less than 30 minutes





This information clearly shows why transmission oil coolers and the various maintenance intervals are recommended for severe usage.



Above 300°F, the metals inside the transmission will warp and distort in varying degrees depending on the severity of overheat. Because this damage occurs and fluid life is so seriously impaired, rocking out of snow, mud or sand should never exceed a very few minutes.