18 February 2009, 13:45
Da's waar, in het OD gedeelte zit wel een slippend gebeuren. Op Brickboard zit een OD guru die beschrijft dat de OD door een halflekkende solenoïde zichzelf kan inschakelen, ergens in het snelheidgebied van de tweede versnelling. Het gevolg is dat de OD niet meer in te schakelen is, omdat-ie al ingeschakeld is.
Dus de vraag is:
- heb je nog een normaal inschakelbare OD in de vierde versnelling?
- of lijkt het alsof je tijdens de tweede versnelling op onverklaarbare wijze sneller gaat rijden zonder dat het toerental oploopt?
Zin om even te vertalen?
Manual M-46 Overdrive Self-Engages. [Tip from Duane Hoberg:] If the clutch only slips in second gear and no other, and the OD does not appear to function, you have a problem with the solenoid on the overdrive allowing the OD function to self engage without input from you.
The solenoid in its OFF position acts as a stopper to keep fluid from an area that creates the pressure build up necessary to move parts internal to the OD and engage the fifth gear. When ON the solenoid valve moves only 1/8 to 3/16 of an inch and allows the fluid past. The seals internal to all this are two very small O-rings. There can be over time a small amount of leakage past the end O-ring and into the electrical area of the solenoid. If this leakage is great enough the valve cannot return to the OFF position and the OD then becomes self engaging. There are all sorts of causes for this to occur, age is one and poor electrical contact which causes heat which bakes the O-rings hard being another.
The solenoid has to be removed and shaken to test it. Yes, that is the test. It must rattle freely or it is bad.
In case anyone is wondering how this can be: Normal drive in the OD for gears 1 to 4 is via a Sprague clutch. (Only works in one direction and very very positive). OD is via planetary gearing which requires a stationary sun gear to accomplish. Hydraulics push the sun gear carrier (which almost everyone calls the cone clutch) into a brake ring which is part of the outside case of the OD. During the transition from Sprague clutch drive to planetary gear drive, the planetary gear drive is trying to make the output shaft move faster but cannot because the sun gear is not stationary and the Sprague clutch is just sitting there trying to drive but cannot. It is this in between area where slippage occurs.
The pump in the OD is a piston style driven off the output shaft of the transmission. The pressure necessary to move ( not engage just move) the internal parts of the OD begins at around 15 mph and with good actuating piston seals is sufficient to maintain OD contact at about 25 mph. Second gear range in the M46. After that, the OD is engaged and the OD doesn't work when the button is pushed. Only because it is already engaged. Change the OD solenoid.
Dus de vraag is:
- heb je nog een normaal inschakelbare OD in de vierde versnelling?
- of lijkt het alsof je tijdens de tweede versnelling op onverklaarbare wijze sneller gaat rijden zonder dat het toerental oploopt?
Zin om even te vertalen?
Manual M-46 Overdrive Self-Engages. [Tip from Duane Hoberg:] If the clutch only slips in second gear and no other, and the OD does not appear to function, you have a problem with the solenoid on the overdrive allowing the OD function to self engage without input from you.
The solenoid in its OFF position acts as a stopper to keep fluid from an area that creates the pressure build up necessary to move parts internal to the OD and engage the fifth gear. When ON the solenoid valve moves only 1/8 to 3/16 of an inch and allows the fluid past. The seals internal to all this are two very small O-rings. There can be over time a small amount of leakage past the end O-ring and into the electrical area of the solenoid. If this leakage is great enough the valve cannot return to the OFF position and the OD then becomes self engaging. There are all sorts of causes for this to occur, age is one and poor electrical contact which causes heat which bakes the O-rings hard being another.
The solenoid has to be removed and shaken to test it. Yes, that is the test. It must rattle freely or it is bad.
In case anyone is wondering how this can be: Normal drive in the OD for gears 1 to 4 is via a Sprague clutch. (Only works in one direction and very very positive). OD is via planetary gearing which requires a stationary sun gear to accomplish. Hydraulics push the sun gear carrier (which almost everyone calls the cone clutch) into a brake ring which is part of the outside case of the OD. During the transition from Sprague clutch drive to planetary gear drive, the planetary gear drive is trying to make the output shaft move faster but cannot because the sun gear is not stationary and the Sprague clutch is just sitting there trying to drive but cannot. It is this in between area where slippage occurs.
The pump in the OD is a piston style driven off the output shaft of the transmission. The pressure necessary to move ( not engage just move) the internal parts of the OD begins at around 15 mph and with good actuating piston seals is sufficient to maintain OD contact at about 25 mph. Second gear range in the M46. After that, the OD is engaged and the OD doesn't work when the button is pushed. Only because it is already engaged. Change the OD solenoid.
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