ATF Temperatures

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ATF Temperatures:

I found some very interesting information on ATF operating temps. This may answer some of the questions on transfer case and transmission failures.

This was taken from the Borg-Warner site.

ATF oxidation
ATF will provide l00,000 miles of service before oxidation occurs under normal operating temperatures of about l70 deg F. Above normal operating temperatures, the oxidation rate doubles (useful life is cut in half) with each 20 deg increase in temperature.
The approximate life expectancy at various temperatures is as follows.
Degrees F	Miles
175	100,000
195	50,000
212	25,000
235	12,000
255	6,000
275	3,000
295	1,500
315	750
335	325
355	160
375	80
390	40
415	Less than 30 minutes

This information clearly shows why ATF coolers and the various maintenance intervals are recommended for severe usage. Above 300 deg F, the metals inside the transmission will warp and distort in varying degrees depending on the severity of the overheat.

Charles 94 4dht

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