Packard Forum Index » V-8 (1955-56)

Greetings All,

Has anyone considered installing an external transmission fluid cooler to reduce the fluid temp? I took the '56 for a tour this weekend and the fluid got very hot and darkened and my average speed was around 55. Caused it to start slipping as was shifing.

Thoughts/Suggestions?

Thanks
Gene

Your car should already have the factory-installed external cooler. Though some have chosen to add an additional cooler, the factory-installed one seems more than adequate for most of us. Perhaps your cooler wasn't the culprit, perhaps the slippage was what raised the fluid temperature in the first place. If the fluid did indeed darken and burn, sounds like you're in for a rebuild. Sorry to hear of the problems.

Ask any transmission shop repairman and he will tell you that you cannot over-cool an automatic transmission. If you are going to be driving the car a lot, ditch the original fluid to fluid trans cooler and install the largest FLAT tube and fin trans cooler you can find. The round tube ones aren't as efficient as the flat tube versions, and they are usually more dependable. These mount directly to the radiator using a special plastic zip tie through the radiator fins. This mounting method makes it easy to remove in a future date, and doesn't affect the originality of the car, it just keeps the trans cooler.

Eric-

Any photos of this new improved version of a transmission cooler?

Quote:

Looked at a lot of catalogues and can't find a flat tube. How about a hint?

JEGS Automatic Transmission Coolers and Lines

Product images may differ from actual product appearance.

Automatic Transmission Coolers
Precision machined from extruded aluminum with CNC machined billet aluminum end caps. The inlet and outlet fittings are located on the same end thus allowing installation along the frame rail, core support or anywhere that space is limited. Now available in two sizes for virtually every application. Includes stainless hardware and two 3/8" hose x 1/4" NPT straight fittings.

jegs.com/images/photos/555-60350.gif

Gene,
Click on above URL for photo of cooler. I use one on a street rod and works great, am planning on putting one on my Exec.

jegs.com or any performance outlet.

What gear was slipping???? There are external adjustments for the low and reverse gears. Follow the manual.

I drive my 56 w/T'ultra long hauls on the Interstate hwy with no problems and no additional trans cooler other than factory equiped.

Possibly u have a plugged up radiator too. Check engine temp. NEED TO USE A GOOD gauge for that.

Plugged up trans filter will cause slipping too. t'ULTRA filter can be removed, cleaned and re-installed.

Does your T'Ultra leak at the pan??????????

I have looked thru a Jegs catalog and see no mention of
flat tranny coolers. Supposedly Hayden (sp) makes one but I have been unable to find it either.

my 55 has a round tube external cooler in place of the original cooler.

i have seen flat tube units before, but i dont know where. try looking for heavy duty units for large pickups. my 1993 dodge with the chrysler a518 drove for 2.5 hours on the highway and the fluid could still be held between the fingertips.

you really cant over cool automatics. the cooler the better.