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MNBoxster · 02-01-2006, 12:43 PM

Hi,

There is a mileage Service Interval on Transmission Oil, what is your mileage? I would not change it before 50k mi. It may seem counter-intuitive, but it is not good to change the Fluid more frequently.

Unlike Engine Oil, the Tranny Fluid is in a Closed System and not subject to contamination or moisture, or the same degree of heat and so does not need to be changed nearly as frequently.

Also, Transmission Oil is very high in Sulphur content (ever notice that Rotten Egg smell?) to keep it from compressing too much. It actually works better when slightly aged. It's Chemistry changes somewhat over time and becomes less reactive with the synchros and other parts.

You should check it annually to ensure it's at the proper level, especially if there are signs of leakage, but too frequent a change and you could create problems. Hope this helps...

Happy Motoring!... Jim'99

02-01-2006, 12:43 PM	#2
MNBoxster Registered User Join Date: Sep 2005 Location: Minneapolis/St. Paul, Minnesota, USA Posts: 3,308	Hi, There is a mileage Service Interval on Transmission Oil, what is your mileage? I would not change it before 50k mi. It may seem counter-intuitive, but it is not good to change the Fluid more frequently. Unlike Engine Oil, the Tranny Fluid is in a Closed System and not subject to contamination or moisture, or the same degree of heat and so does not need to be changed nearly as frequently. Also, Transmission Oil is very high in Sulphur content (ever notice that Rotten Egg smell?) to keep it from compressing too much. It actually works better when slightly aged. It's Chemistry changes somewhat over time and becomes less reactive with the synchros and other parts. You should check it annually to ensure it's at the proper level, especially if there are signs of leakage, but too frequent a change and you could create problems. Hope this helps... Happy Motoring!... Jim'99 Last edited by MNBoxster; 02-02-2006 at 09:49 AM.