Re: 5 Speed Transmissions

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

Dorothy,

I asked my husband to explain this to me.  Here is the scoop.  He said that
particularly if you have an automatic even if it has an auxillary cooling
system (doesn't matter what make), it's never a good idea to haul in
overdrive.  The reason being, there is a torque convertor that slips inside
an automatic.  In the higher gears (overdrive) this convertor slips more
causing friction and a heat build up within you transmission fluid.  As the
transmission fluid heats up, it begins to lose it's ability to lubricate. As
the lubrication factor decreases, there is more friction, more heat build up
and eventually the transmission fluid will fail, leaving metal on metal.
That's when things break.  There are alot of factors that go into how long
it takes for this to happen.  Terrain, speed, degree of throttle, etc.  

Now in a manual transmission, he said that some are better than others, but
that still you always have a risk factor.  When your transmission in in 4th
gear, you have a direct ratio of 1 to 1 between your engine and the rearend
(essentially by-passing the gears) as your drive shaft is turning at the
same speed as your engine.  When you shift into 5th or overdrive, your drive
shaft is then turning faster than the engine.  It all depends on the
strength of the gears in 5th/overdrive, the amount of torque, terrain, and
throttle speed again as to whether on not you have a failure at this time
when hauling.  The temptation with a manual for many people is to stick it
in overdrive, put the cruise control on and go.  When you do this, you never
know where your throttle is, it can be wide open or not, just to maintain
your speed.  Anyway, he said that he loves people who haul in 5th/overdrive,
as it means bread and butter at our shop <g>, but I'd better not do it,
because he doesn't want to have to traipse across the country to come rescue
me if I break down.

Anne and the Horses
(Dyskrete, Stuffy, Hadia and Tifla)
At 08:10 AM 1/12/98 -0800, you wrote:
>Ask your husband if that applies when you're on a freeway that's flat.  I
>put our Chevy Diesel into overdrive when I'm going 60 on the freeway, but
>I'll quit doing that if he says to.
>
>Dorothy & Elly
>taylorsville, ca
>
>----------
>> From: AJ's Classical Gas <ajsgas@imt.net>
>> To: ridecamp@endurance.net
>> Subject: 5 Speed Transmissions
>> Date: Saturday, January 10, 1998 12:58 PM
>> 
>> You said that you had a 5-speed transmission in your 1996 Chevy diesel. 
>I
>> only know that my husband has told me never to haul the trailer in
>overdrive
>> or 5th gear.  He is a mechanic and has replaced many 5th gears in
>> transmissions where the person was hauling a trailer (sometimes that gear
>> has gone out in only one trip).  So, to be on the safe side, don't use
>> overdrive/5th when hauling, because if it does break, your stuck till a
>> wrecker hauls you in (ick).
>> Anne & the horses
>> (Dyskrete, Stuffy, Hadia and Tifla)
>
>
Anne & the horses
(Dyskrete, Stuffy, Hadia and Tifla)