At elevated operating temperatures, ATF oxidizes, turns brown and takes on a smell like burnt toast. As heat destroys the fluid’s lubricating qualities and friction characteristics, varnish begins to form on internal parts (such as the valve body) which interferes with the operation of the transmission.
What happens to transmission fluid when it gets hot?
The optimal temperature range for transmission fluid is 175 to 220 degrees. Above that, for every 20 degrees bad things happen, starting with formation of varnish at 240 degrees, followed by seals hardening, plates slipping, seals and clutches burn out, carbon is formed, and, ultimately, failure.
Can hot weather cause transmission problems?
The reason summer temperatures are so tough on auto transmissions is that they raise the temperature of your transmission fluid. If you’re stuck in stop-and-go traffic during the summer, the combination can be even harder on your transmission.
Does transmission fluid level go up or down when hot?
Pull the dipstick out again and check the fluid level. If the engine is cool, it should be at the upper end of the “COLD” mark. If the engine is hot, the level should be at the upper end of the “HOT” mark. If it’s lower, you should add some amount of automatic transmission fluid.
What temp does transmission fluid degrade?
The ideal fluid temperature is under 175 degrees, but as fluid ages it starts to break down and lose its capacity to cool down the transmission. This is when transmission overheating occurs. At 220 degrees, varnish forms. At 240 degrees, seals start to harden.
What do I do if my transmission is overheating?
What to do when your transmission is overheating:
- Stop driving immediately and let your transmission cool down.
- Make a note of what you were doing, where you are, what’s happening (noises, etc.)
- After cooling down, start back up & gingerly continue on your way.
How hot is too hot for transmission fluid?
If the temperature gets above 250 degrees F., rubber seals begin to harden, which leads to leaks and pressure losses. At higher temperatures the transmission begins to slip, which only aggravates overheating even more. Eventually the clutches burn out and the transmission calls it quits.
What does it mean when it says transmission hot?
The DIC displays this alert when the transmission fluid is too hot, which prevents the transmission from cooling properly. When the DIC displays this message, you should stop and turn off your car. The alert will disappear when the transmission fluid has returned to a safe temperature.
Is it bad to overfill transmission fluid?
Transmission Fluid Leakage: Adding too much fluid will cause high pressure inside of your transmission. This is very bad and could cause your transmission to start leaking fluid everywhere. … This can cause wear and tear on your transmission and damage the system in the long run.
How often should transmission fluid be checked?
Transmission fluid flushes should be performed every 30,000 miles and transmission fluid levels should be checked, at least every six months. Now that you know how often to check your transmission fluid and the steps on how to do so, you’re one step closer to extending the life of your transmission!
Does transmission fluid expand when hot?
If the fluid level is OK when cold, it should also be within the cross hatched area for “H” as well. The reason for checking when both hot and cold is transmission fluid expands as it is heated. … Transmission fluid expands and keeps expanding the hotter it gets.