On May 25, 2007, at 9:07 AM, [EMAIL PROTECTED] wrote:
Overdrive creates tons of
heat in any tranny if it's pulling hard and that heat will destroy
junk US
made trannies.
That's what I thought, too, but it wasn't the case, at least with my
700R4. I pulled a 26', 4000lb airstream for a while with a caprice
wagon, and installed a trans temp gauge and a big cooler. I found
there was no difference between running wide open in overdrive and
running wide open in direct--as long as the converter was locked up.
Since the converter on my trans was always locked in OD, this was
never a problem in that gear. However, when the converter unlocked in
direct, the temps would start to climb some, indicating that the real
heat was being produced by the TC, not the gears and bearings. So for
that setup, at least, I didn't hesitate to tow in OD when it would
pull cruising speed (65) and never had a problem. And this trans had
150+k on it at the time. I've never done a similar test with an
uncooled manual OD trannies, although I pulled a 16' travel trailer
with a Chrysler 4-speed OD (Behind a 225 slant six!) in overdrive
with no problems also, but I figured the 225 didn't make enough
torque in overdrive at cruise to do any damage.
Dan
Dan Weeks
Freelance Writer and Photographer
515/279-4825
[EMAIL PROTECTED]
