[VAC] Re: Towing in OD

[Dan Weeks <theprofileco@xxxxxxx>]

I second scott on this one. I was given one trailer by someone who towed it
in OD, according to the mfr, and cooked his trans in less than 1,000 miles
on a car with less than 10k miles on it. This guy had towed the same trailer
for 25 years previously with no problems. But this was his first AOD trans.

My neighbor killed the trans in a new taurus by making one 400 mile trip
over flat land with a small popup doing the same. Again the owner's manual
OKed towing in OD. 

I'd add one more caveat to Scott's list below--find out if the transmission
can unlock the torque converter in overdrive. Some can, some can't. If the
torque converter is locked at all times in overdrive, good. If the converter
clutch can unlock the converter in overdrive DON'T TOW IN OD. It's converter
stall (allowing the converter to provide maximum ratio reduction under hard
load) that heats up transmissions the most. A converter locked situation
creates considerably less heat.

Another way to run cooler is to upshift the trans manually when towing, and
allow the engine to wind up quite a bit in each gear. This greatly reduces
the amount of converter stall, allowing the trans to run cooler. I also
believe it increases the effectiveness of the trans cooler by circulating
the fluid at a higher rate. Anyway, shifting manually and late is what my
trans shop recommends when towing, and so far I've got 160,000 on a rather
underpowered rig with a not-terribly strong AOD trans (Chevy caprice 305)
with no transmission problems. But I'm still about to add a trans temp
gauge, just to be sure.

Dan
75 Argosy 26