RE: 5 Speed Transmissions

["AJ's Classical Gas" <ajsgas@imt.net>]

>
>At 06:31 PM 1/14/98 -0700, you wrote:
>>This (torque converter slippage) may have been the case in the past, but
most late model auto have locking torque converters that eliminate lost
motion after a certain speed.  Towing in OD depends on overall gearing and
transmission design.  I tow a 12-13,000 lb trailer in OD with my Ford with
the E4OD
>>auto with no x-mission heating problems.
>>
>>Jerry Barfield
>>----------

Hi again Jerry,

I finally got the whole technical discussion from my husband this morning on
the way to town to get parts.  We do our best talking in the truck these
days <g>.

As you stated, most automatics now have locking Torque convertors. 

Locking TCs were put in automatics to give then the mileage equivalant of a
manual transmission.  The LTCs are not alwasys in lock position when you are
driving.  They only lock when the parameters are right, such as high vaccuum
and low load.  When you are under a load, such as pulling a hill, passing,
accellerating, or pulling a load, these preset parameters are not always met
and then the convertor is no longer locked.  For example, say you have a GM
with a tach, doing approximately 65 mph on the freeway, as you start to
accellerate, you will see your rpm rise approximately 300 rpm even before
your speed has increased.  That rpm difference is taken up in the TC as
slippage which then generates heat, even if you have a Locking TC this
happens, because as I said, it is only locked if the preset parameters are
met.  For longevity of the truck and less stress on the whole system, it is
wisest not to drive in overdrive.  I don't believe any of the manufacturers
recommend it in their owner's manuals either.

Anne and the Horses
Dyskrete, Stuffy, Hadia and Tifla
Anne & the horses
(Dyskrete, Stuffy, Hadia and Tifla)