טמפרטורת עבודה של גיר אוטומטי בדיסקברי 2

מוגש כשירות לחובבי הכרכרות. כולל נקודות מדידה אופציונליות והשוני ביניהן.
אוחזר מהאתר של אשקרופט בכתובת הזאת:
http://www.digi-panel.com/trannyoil.htm

Automatic Transmissions
OIL TEMPERATURE MEASURED AT CONVERTER OUTLET TO COOLER:

300° F=

The maximum allowable temperature. This is the recommended place to install a temperature gauge or sensor. Do not allow the converter outlet temperature to exceed 300° F. The temperature at this location will vary significantly because of load, hill climbing, etceteras. If the temperature reaches 300° F, reduce throttle. To lower transmission temperature with transmission in neutral, run the engine at 1,200 RPM for at least 2 - 3 minutes while keeping a close check for signs of engine overheating. A transmission in a heavy throttle, stall condition (a typical situation is rocking a vehicle stuck in mud, sand, or snow), may increase temperature at a rate of 1° degree per second of stall.

OIL TEMPERATURE MEASURED AT OIL PAN OR SUMP:

150° F=	The minimum operating temperature. Note: It is possible in low ambient temperatures to overcool the transmission with auxiliary oil to air coolers. Oil to water coolers in standard factory radiators will normally not overcool a transmission.
175-200° F=		Normal pan oil temperature operating range.
275° F=	Maximum allowable oil pan temperature for short durations during long hill climbs.
300° F=	Damage occurs to internal transmission parts, including warpage of metal parts, degradation of clutches, and melting of seals. Transmission oil oxidizes, (forming varnish-like substances causing further clutch slippage and compounding heat build up) and transmission oil life is extremely short.

AUTOMATIC TRANSMISSION FLUID LIFE / TEMPERATURE RELATIONSHIP:
Automatic transmission oil can provide up to 100,000 miles of service before oxidation requires replacement, at an operating temperature of 175° F. Above this temperature, the oil oxidation rate doubles with each 20° degrees F increase in oil temperature. See chart.

DEGREES F	MILES	DEGREES F	MILES
175	100,000	295	1,500
195	50,000	315	750
215	25,000	335	325
235	12,500	355	160
255	6,250	375	80
275	3,125	395	40

Note: Transmission oil and filter should always be changed more frequently when driving with heavy loads (RVs), typically at least every 25,000 mile intervals, since converter outlet temperatures then normally far exceed the ideal 175° F.

בסיכום זריז,
טמפ' מינימלית לעבודה: 65 מעלות צלזיוס.
טמפרטורת עבודה תקינה: 80-95 מעלות צלזיוס.
פיקים קצרים שהגיר מגיע אליהם בעומס: 135 מע"צ. לאורך זמן יגרום לנזק אבל תקין במאמצים רגעיים (עליה עם נגרר כבד וכו'...).
נזק מיידי לגיר: 150 מע"צ.