Auto Trans theory type question

[Polara_500]

So there's been a fair bit of chatter in recent years of people installing a deeper pan on their transmission, but it seems most insist it must be accompanied by a means to lower the filter closer to the bottom, lengthen the dipstick and maybe a mod or two more. Is this absolutely necessary, and if so, why? I realize the unit will not be able to access the extra volume so it would be just extra volume, but since the dipstick is calibrated for the original filter configuration if you just fill to the dipstick wouldn't there be adequate fluid for the pump, or am I missing something here?

Now the reason for the question - I inherited a new 727 pan that was made at least 20 years ago or so that's intended to add extra cooling by having several finned tubes running through the bottom of the pan, (and even has "turbulators" installed in the tubes). These tubes are open to the atmosphere and air flow to add the cooling. These extra tubes would obviously interfere with trying to lower the filter to nearer the bottom of the pan. I realize this won't be near as efficient as an external front mounted cooler, but the pan is new and not beat to crap, so why not use it?

 

[Big_John]

You don't have to lengthen the dipstick. The only reason I could see would be if they wanted to not run the full capacity of the pan, maybe to cut down the oil "windage" on the rotating assembly, but I don't think that's an issue.

My car has a pan like you describe on it. It was installed by one of the previous owners. I've never had it off, but I don't see how the pickup/filter could be anything other than the stock location. I've never had any issue with it, but I don't know as it does any good or not.

 

[moper]

With deep pans you get a spacer and longer screws for the filter. So the filter is the same, and the level of oil is still the same, there's just more of it, so no dipstick mod. The pan you have probably does not have much more of a sump to it and the filter is in the same spot... I never owned a Derale pan (I think that's what you have) but I wouldn't worry about using it. Just make sure the level stays full.

 

[Zwap]

What's the reason to add a filter spacer?

 

[DC118us]

I'm definitely no transmission expert, but I believe the reason for the filter spacer (which your type probably doesn't need) is that there needs to be a specific height that the filter rests above the bottom of the pan floor.

 

[70bigblockdodge]

What's the reason to add a filter spacer?

Gets the filter back down to the bottom of the pan. More fluid allows more heat to absorb in more fluid.
The OP has a pan with air tubes passing through to cool fluid, I would not throw it away but I would not look for one to buy.

 

[Zwap]

Gets the filter back down to the bottom of the pan. More fluid allows more heat to absorb in more fluid.

Ok, so the heat of the fluid is lower in the bottom of the pan?

 

[Darter6]

Physics say heat rises.So in theory, even though ever so minute, the bottom of the pan is the coolest spot.

 

[Polara_500]

Actually the pan was made by Integrity. Pulled it out this morning and took a pic for giggles. You can see one of the "turbulators" where I pulled it out of the tube a few inches - a twisted piece of metal to encourage any air passing through to move with a twisting motion for increased heat transfer according to the literature. This thing is actually quite heavy, not that that's an issue with a C.

 

[330dTA]

I'd like to see real numbers of the cooling gains that tubing is supposed to give. To me it seems theoretical: the diameter of the tubes is minimal, and the air passing under the car is very turbulent. I wonder if there is any air flow at all in those tubes.

 

[Polara_500]

I'd like to see real numbers of the cooling gains that tubing is supposed to give. To me it seems theoretical: the diameter of the tubes is minimal, and the air passing under the car is very turbulent. I wonder if there is any air flow at all in those tubes.

I have to agree with your thinking on that, it just seems like a stout and well made pan and not deformed from past over torquing of bolts and such. I'm not counting on any significant cooling, more just the benefit of a new pan at no cost.

 

[70bigblockdodge]

Ok, so the heat of the fluid is lower in the bottom of the pan?

No just more fluid in all to absorb the same heat. Temp would technically lower in the bottom of the pan but for how fast the fluid moves through the system not much difference, actually the fluid at the rear of the pan would be cooler, that is where fluid returns from cooler.

 

[moper]

The filter needs to be close to the pan's bottom to stay in un-aerated oil like the oil pickup in the bottom. So the spacer is needed.
I would expect that there is a decent drop in temps from that pan. But it is from the added volume as much as the airflow. I can also tell you those twisted vanes - they are also in the boiler of my house... They do add efficiency to the heat exchange.

 

[CBODY67]

The "cooler pan" you have was popular in the later 1970s, as an alternative to the aluminum pans with external fins. For this type of pan, NO need to lower the filter level as the level of the stock pan is basically the upper level of the tubes inside of the cooler pan.

IF the pan was a real "deep pan", usually 1" deeper than stock, THEN you'd need a spacer to go between the filter and the valve body/pump intake AND longer screws to hold it all together. This would keep the filter at the desired "bottom of the pan". Seems like Mopar Perf had a kit for the deep pan and filter extension items?

Not sure how effective the tubed cooler pan really way, but they looked like they worked. Any cooler fluid would be at the bottom, but would not be circulated upward to the top of the tubes and the filter/intake, normally.

The real benefit of many of the deep pan kits was the return of THE DRAIN PLUG for atf changes.

CBODY67

 

[cantflip]

Agree, the drain plug makes life so much easier and cleaner during maintenance... the rest is probably not nearly as effective as a add on cooler, but to replace a mangled pan... go for it.