My 86 has a TurboHydramatic 475 transmission. It has a transmission temperature gauge (good thing) but the sender is located in line going out to the transmission cooler. (Not so good) While this gives me an idea of peak torque convertor ATF temps, it does not tell me what the temp is inside the main transmission.

I wanted a gauge in the pan. I decided to install a fitting in the pan to allow me to move the temp sender.
First, get the proper gasket and filter. (My parts buddy says the gasket looks like Texas to him, he needs to get out more.)



Then drain/remove the pan. Yuck. This is one of the messiest things in all the car/truck work in my life. In this case the cross member prevents the rear of the pan from swinging down, so you tip it forward and it runs out more... Then it drips for hours... This is another really nice thing about this new fitting. It will double as a drain plug. It won't get all the ATF but if I drain the pan and let it drip (internally) then remove the pan I'll never have this mess again.

I had to find a flat spot on the side of the pan away from the filter. The fitting is Hayden part #270





Reinstall new filter, gasket, sender and wire. The wire was already long enough. (Oops, at least my toes are in focus)



Another mod was to the transmission cooler. The original was a six "tube and fin" type mounted low behind the bumper. Nothing really wrong with the cooler but tube and fin types have limited surface area on the tubes and only six of them.



I decided to use a "stacked plate" type from Hayden instead. (30 flat tubes)



They are similar in overall size, but the plate style will throw more heat. (There's those dang toes again...)



Last year, I removed the factory AC but kept the cooling fans. They have thermostatic and manual driver control. I put the trans cooler behind the left fan (driver side, right side in this pic) in the space where the AC condenser was. When the fan comes on it cools both engine and trans directly. The rest of the time there is direct airflow through the grill. (That orange wire nut is TEMPORARY and it is a ground wire!)





I still have to bolt the new cooler to the transverse fan brackets. (Zip tie for now!)
I won't know the results till I head back home in April. We'll see.

If anyone wants the old cooler it is still OK and usable. Free to good home!

Now, on to the new HEI distributor and timing curve games!

Good job and well documented..................

Looks Great - Nice Job!!!

Great looking mod....Sure looks like it oughtta help

Thread drift: I have a small tube-n-fin tranny cooler installed after the OEM tranny line that goes in to and then out of the radiator - standard set-up I believe. My radiator is about 20 years +/- old, functions well, doesn't leak, holds pressure and there's no need to replace it (yet). However, the thought of a radiator failure that could inter-mingle coolant and tranny fluid sounds pretty scarey, and I certainly want to protect the recently installed Jasper TH-400. So I'm thinking:

If I install an oversize stacked-plate tranny cooler, would I be adding enough extra cooling capacity that I could bypass the radiator tranny cooler altogether? Seems to me that unloading the radiator from tranny loads would increase the radiator's capacity to address combustion cooling & help lower engine temps.....'Course, I guess I lose some radiator efficiency from the hot air from the stacked plate tranny cooler going through the radiator fins, etc, yada yada....But it would be peace of mind if I could have adequate tranny cooling & combustion cooling totally independent of each other......

So who's got the thermal engineering know-how to determine the trade-offs that I need to consider?

PS: Already have extra deep tranny pan (+2 qts), with cooling tubes in bottom of pan....

Thanks!

I considered bypassing the radiator cooler as well but like you I wasn't sure how big, location compromises etc. I chose that cooler because of the stacked plates and it happens to fit perfectly between the electric fan brackets, not really by BTU rating.

Now that I have the pan temp I guess I could bypass the radiator cooler and see what happens to the "normal" temp (once I get a chance to run it and find out!) I will report then.

RVers like to discuss the virtues of pan temp vs converter out temp. I like them both.

My preference is to have a selector switch on the trans temp gauge that allows me to read converter out temp as well as pan temp.

Converter out temp alerts you of heat rise, giving you the opportunity to shift down, slow down, turn on a fan, turn off AC, whatever. This can be useful in traffic as well as hill climbing.

Pan temp tells you if you have enough cooler or whether your heat management is doing the job.

I was thinking of that, too. I can install another sender back in the line and run another wire. Might help "anticipate" heat loads and turn on fans, etc.

quote:

Originally posted by Lee:

So who's got the thermal engineering know-how to determine the trade-offs that I need to consider?

No engineer in a cubicle can help you. Just keep adding coolers until your trans stays cool.

Your load, engine, driving habits, ambient temps, inclines, etc make calculating only educated guessing.

I have kept adding trans coolers and am up to 119,200 BTUs in addition to the radiator heat exchanger. Probably will need more come August.

Steve,

Another suggestion is the installation of a different style trans. oil pan.
I had a 1968 Chevy 3/4 ton van with a 5.7 engine in it. The trans. oil pan was an after market with air tubes that ran thru the entire pan from front to back. This allowed a lot of cooling by the air just going thru those tubes.
I have sold the van and don't recall the name of the pan, however I'm sure you could locate one.

Jim

1985 Barth Regency 35ft
DD 225hp Ally trans.4 speed

quote:

don't recall the name of the pan, however I'm sure you could locate one

I think this is what you're describing:

http://www.transmissioncenter....ooling_Products.html

I've got the extra deep version, and noticed an immediate improvement - 'bout 12-20F

Prices are footballed, so shop around......

Oh sure... Thanks Lee (I think)... one more "cool" thing to buy for Barth!

Lee,

That's the one I had on my van. It did work great and is so simple.


Jim

1985 Barth Regency 35ft
DD 225hp, Ally trans- 4 speed

I ran back to Michigan from Florida. Transmission pan temp was normally about 160 F. Even on long hills with high throttle it peaked about 185 F. This was at about 80 F outside temp.

I saw temps almost as high when stuck in stoplight to stoplight traffic (for miles) at over 90 degrees in Florida.

I am very satisfied with this cooler setup. It seems to be very adequate for my rig so far. I haven't tried towing any more weight yet, though.