Dan Masters writes
>
>
>In a message dated 98-06-04 09:02:07 EDT, bschwart@pacbell.net writes:
>
>> You would certainly lengthen the life (at least of the switch and the
relay
>> and possibly the solenoid) by at least double by halving the amount of
>> actuation/de-actuation cycles! Although there's not really anything to
>> wear out in a solenoid I have herd stories of them failing and this may
be
>> due in part to cycling fatigue of the connections to the wire of the
coil
>> inside the solenoid itself. This and the heat of the unit while in
>> operation, so reducing the cycling times surely can't hurt!
>
>Barry,
>
>There are actually two coils in the OD solenoid -- One heavy duty coil to
pull
>the solenoid in place, and another lighter duty coil to hold it in place
after
>it has been pulled into place. The heavy duty coil draws a LOT of
current.
>Once the solenoid has actuated, it operates a switch which disconnects the
>heavy duty coil, leaving only the low current drain holding coil
energized.
>This switch is a common failure point. Anytime you switch an inductive
load
>(coil), the switch contacts take a beating. A diode would probably help,
but
>it would have to be a humongous diode for this application. I don't have
hard
>data, but I have been led to believe that the larger coil draws as much as
>thirty amps!
>
>You're right, the fewer times you operate this switch, the better (as well
as
>the manual actuating switch).
>
>Dan Masters,
>Alcoa, TN
Dan,
This is true for the A-type overdrive but the J-type uses a pilot operated
valve which requires much less force from the solenoid and concequently
can get by with a single coil solenoid that draws about 5 Amps. I don't
know about the D-type.
But Barry is right and I think that if Triumph could have done it that
way on the three rail transmission, they would have. As for me I don't
shift between 3rd O/D and 4th O/D, I switch between 4th O/D and 4th
straight!
It's much easier and quicker. I occasionally shift from 3rd O/D and 4th
O/D on
those rare occasions that I switch on the O/D in 3rd.
Dave
P.S. see you in Hudson WI
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