Aux. electric trans coolers

[John Marinan]

Do these really work? What's the preferred location? Would the fluid still need to run through the radiator?
I can't help but wonder if the trans fluid actually stays cool after it runs all the way back from the radiator.
I have a C4, it has of those oil pans with the cooling tubes running through it.

 

[bax]

Yes coolers do work. No they dont have to still run thru the radiator. there is nothing cool about transmission fluid. heat is the death of automatics, cooler is better.

 

[DanWheeler]

running it through the radiator can be beneficial to raise the fluid temperature if it is very cold outside. You want your fluid about the same temperature as your engine.

I run my aux cooler AFTER the fluid has passed through the radiator. If the fluid doesn't get cooled down to 180/190 going through the radiator, the thermostatic switch on the aux trans cool turns on so the aux cooler can finish the job and get it down to 180.

It is important to monitor your trans fluid temperature at the pan and not anywhere else along the way. Whats in the pan is most important because that is what the transmission is using.

 

[Sac '68 sport]

You want your fluid about the same temperature as your engine.

I disagree with this statment to some extent. Ideally you want it cooler than the motor operating temp of 190-220 depending on your thermostat. If you can get it to 160-175 that would be best.

TCI - TECHNICAL INFORMATION: Transmission Life Expectancy
http://www.tciauto.com/Products/TechInfo/trans_life_expectancy.asp

Here's what I did with my cooler. It kept in the 160 range most of the time even when the fender was solid. It would get hot sitting in traffic on really hot 100+ deg. days though. Shouldn't be any problems now with this new mod to the fender. I don't run it through the rad. as this horse doesn't see cold enough temps to have to worry about it.

 

[rtreads]

I can tell you this. I had a 6 pass cooler with a small 6" or 8" fan. I was having tranny heat issues with that setup. A fellow CB member, had suggested that I ditch that cooler and get a cooler with the design of a bunch of plates stacked up. Meaning not the tube that passes back and forth. Checker/Oriley has them here in CO. I got the biggest one they had, the 30,000 gvw one. I dont know why they rate them in gvw, but they do. Anyway, its for RVs and buses. Its about 1/2" thick, and 9x10". It works GREAT!!! All I did was install it in front of the radiator, off to the passenger side. I have not hit 180* since. Its great because there is no fan to turn on, no wiring, ect. I suggest getting one!

 

[DanWheeler]

that looks familiar:

yes 220 definitely too hot. I was thinking more along the lines of 180 which is what the Derale fan switch turns on at. Like I said, radiator takes it down to 190 then the Derale gets it down to 180.

 

[John Marinan]

It sound like stacked plate is better whether it has a fan or not.

 

[Deano]

I installed mine in front of the rear gas tank. Put a 1" spacer between the floor and the derale cooler with the thermostat control for the fan. It seems to work great there. Out of site to.

 

[DanWheeler]

I like the idea of mounting the trans cooler somewhere remote. Probably get a little bit more cooling running through the long lines especially if they are steel lines.

I'm wondering if the length of the tubes can be a problem though? the longer the lines, the more fluid friction and harder the pump has to work.

 

[Viperwolf1]

I like the idea of mounting the trans cooler somewhere remote. Probably get a little bit more cooling running through the long lines especially if they are steel lines.

I'm wondering if the length of the tubes can be a problem though? the longer the lines, the more fluid friction and harder the pump has to work.

Mount it under the rear seat and call it a heater.

 

[Sac '68 sport]

that looks familiar:

yes 220 definitely too hot. I was thinking more along the lines of 180 which is what the Derale fan switch turns on at. Like I said, radiator takes it down to 190 then the Derale gets it down to 180.

Dan, that's a great idea...
Do you have your fan blowing or sucking and why?
I was thinking that I was going to wire mine to suck up cool air from the wheel well, but I'm a little concerned with pulling up dust, water, etc.


I read on another forum, (the explination seems to make sense), that even though your motor reads 190 which is probably the upper exent of where you want your transmission normally operating, using the in radiator coolers is ok because the actual fluid temps going back to the transmission post cooler are normally quite a bit lower than that. Never used one so can't really comment on how that actually works out.
I really like the Derale stacked plate cooler and fan. I think one in front of the rad would work good too but the fit looked too tight to me to have an AC condenser in there too.

 

[DanWheeler]

I currently have mine sucking cold air from the fender through the cooler and exhausting it into the already hot engine bay.

I tried it in push mode as well. I found it did not work as well because it was pushing hot air from under the hood through the cooler.

I also tried the Derale cooler without going through the radiator transmission cooler. The Derale would run continuously trying to get it down to 180. It's a nice little cooler but it's not good enough to do the job on its own in my case. Maybe it would have worked better if I were running just the Derale but sucking cold outside air. I think I had it set up as a pusher fan at the time I was running it solo. (not through the radiator)

Just like there's no replacement for displacement in engines, you can't beat the surface area cooling capacity of a large radiator.

I still dont have this thing dialed in though. The Derale thermostatic switch turns on at 180 and my thermostat for the engine is 190. I have the Derale thermostatic switch wired in AFTER the Derale unit. Even after going through the radiator AND through the Derale I still sometimes find that the Derale fan runs continuously.

not sure if the 4R70W just generates a ton of heat or maybe my overall cooling system is still inadequate for heavy wheelin or what the problem is. I really need to get a temp sensor in the pan to see whats happening.

 

[jw0747]

I'm a firm believer in not running the trans fluid through the radiator. after blocking off the radiator trans cooler and running the lines through aux. coolers my engine now runs cooler.
engines in Broncos normally run hotter so IMHO your radiator is doing double duty trying to lower the temp of both engine coolant and trans fluid. my $.02

my set-up is two small aux coolers w/o fans in front of radiator and a Derale cooler w/fan on top of passenger inner fender. cooler is better because too much heat is a tranny killer.

 

[Viperwolf1]

I'm a firm believer in not running the trans fluid through the radiator. after blocking off the radiator trans cooler and running the lines through aux. coolers my engine now runs cooler.
engines in Broncos normally run hotter so IMHO your radiator is doing double duty trying to lower the temp of both engine coolant and trans fluid. my $.02

my set-up is two small aux coolers w/o fans in front of radiator and a Derale cooler w/fan on top of passenger inner fender. cooler is better because too much heat is a tranny killer.

Your 2 coolers in front of the radiator are lowering it's efficiency just like the original trans cooler did.

 

[jw0747]

Your 2 coolers in front of the radiator are lowering it's efficiency just like the original trans cooler did.

please explain...

 

[Viperwolf1]

The coolers heat the air going through the radiator. Heated air is less able to pickup heat from the hot radiator. Less heat coming out of the coolant is the same as heat added to coolant from integral trans cooler.

 

[Sac '68 sport]

I currently have mine sucking cold air from the fender through the cooler and exhausting it into the already hot engine bay.

I tried it in push mode as well. I found it did not work as well because it was pushing hot air from under the hood through the cooler...QUOTE]

Thanks Dan.
I'm running a C-4. You may be right, the C-4 may just run cooler than the 4R70W. Just the Derale alone on the pass. fender was good enough other than having some trouble on really hot days sitting in traffic even before I cut the hole for the screen. No T-stat on it. Just a mannual switch to the fan. I turn it on after a mile or two once it gets warmed up and leave it on. I have it right next to the power switches for my raido and tach so I don't forget. Although those switches won't be there with the new rewire...
I also got a B&M gauge from summit. The sensor isn't in the pan. It's right at the outflow port that goes to the cooler. I was having trouble with it appearing to run hot (bad sensor) so I bought a lazer temp probe and the pan was a nice and cool 162-165 after some normal city driving, which matched nicely with what the gauge said before it went all haywire and said I was cooking it. It would probably be fairly easy to make it work in the pan. I think you could just drill and tap, but I don't think it's necessary, at least in my case. It seems to be right on with what's going on in the pan and lines to the pan.

 

[jw0747]

The coolers heat the air going through the radiator. Heated air is less able to pickup heat from the hot radiator. Less heat coming out of the coolant is the same as heat added to coolant from integral trans cooler.

In theory you are correct no disagreement here. But in my practical application the "before" and "after" cooling system operating temps on both gauges (rad. and trans) would indicate my set-up is working much better than it did before the 2 front coolers were installed. Probably because both are smallish.

 

[SurfCityEB66]

Would anybody be opposed to mounting the trans cooler w/elect fan in front of the rad ONLY and bi-pass the rad all together? Obviously this would add some extra heat to the rad fluild but right now I just have the 6 pass cooler in front of the rad no fan. Seems to overheat the trans when outside temp in desert get over 80*... I'm looking for an easy mount;D and since the SS lines are already running I figure this may help a little by the added fan and easier on the wallet???

Thoughts....

 

[MarsChariot]

Here is what I did. I removed the radiator from the equation and installed a rail type remote cooler for general cooling during times when the '76 was in motion. And I installed a Derale flat-plate ("Atomic") remote cooler in series for low speeds, crawling, or pulling. After mapping out (i.e., running through a small mud patch and looking at the spray pattern) I installed the aluminum shield in a strategic position to protect the remote Derale from mud and small stones.