I was told to bypass the through the radiator trans cooler and install an external trans cooler(largest possible) on my 1990 f250 with an e4od trans. This is supposed to keep the trans alot cooler when operating at full summer temperatures. Are there any drawbacks to doing this?
Bypasing factory trans cooler
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disadvantage?? well how about not being as effective as running the second cooler after the factory cooler..makes much more sense that way.
Factory out to 2nd cooler in 2nd cooler in to transmission..will cool the fluid more .
Factory out to 2nd cooler in 2nd cooler in to transmission..will cool the fluid more .
I agree with DS. Kinda depends (the smell of the old folks conga line) on the factory rad cooler. If it's just a one looper the hardly will make much difference, but if it's of decent size and a few loops, keep it in for the volume. Add and external filter, too.
I guess a huge benefit of skipping the in rad trans cooler is prevention of fluid comingleing - which DOES happen with pin hole leaks.
I guess a huge benefit of skipping the in rad trans cooler is prevention of fluid comingleing - which DOES happen with pin hole leaks.
Keep the original cooler.
Almost all aftermarket trans cooler instruction say to.
Route it there first, then the supplemental cooler.
It can help get things warmed up in cold weather, and add cooling in real hot conditions.
Almost all aftermarket trans cooler instruction say to.
Route it there first, then the supplemental cooler.
It can help get things warmed up in cold weather, and add cooling in real hot conditions.
hmm thats interesting...I have a Performabuilt transmission in my Z28 with a 3000 stall converter with a 22,000 GVW external cooler. They specifically instruscted me to bypass the radiator cooler, and only run the external cooler.
In a place with cold weather (new york), and you plan on driving the car in such weather, then run the cooler inline with the radiator. The coolant in the radiator will help warm up the trans oil to temp, and the cooler will keep it from getting too hot.
There is such thing as too cold trans fluid.
If you live somewhere nice and warm, then bypass the factory heat exchanger by all means.
The most important thing is to flush out the lines with a kooler klean aerosol cleaner.
Lots of sludge likes to get in those lines.
There is such thing as too cold trans fluid.
If you live somewhere nice and warm, then bypass the factory heat exchanger by all means.
The most important thing is to flush out the lines with a kooler klean aerosol cleaner.
Lots of sludge likes to get in those lines.
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The trans will warm way faster than the coolant in the rad. The converter generates heat right off the bat. In colder weather your ^T across the rad is substantial. Many of you should be feeling a stone cold hose (YMMV).
That is, I'd say that the trans is warming the rad way before that coolant thermostat ever opens.
That is, I'd say that the trans is warming the rad way before that coolant thermostat ever opens.
Travis - Who recommended to bypass the original cooler?
The transmission rebuilders, or the new cooler manufacturer?
I can't see why you would want slower warm up, or less ultimate cooling.
Maybe there is a specific problem with that stock cooler.
The transmission rebuilders, or the new cooler manufacturer?
I can't see why you would want slower warm up, or less ultimate cooling.
Maybe there is a specific problem with that stock cooler.
The transmission builders recommended to bypass the radiator. The cooler manufacturer didnt have any recomendation on bypassing the radiator or not. There's no problem with the stock cooler on these cars. Its just that its not needed if your running an external cooler. Also, sometimes its hard to get the transmission fluid much cooler then the coolant temperature in the radiator. I really doubt you have to worry about your transmission fluid not heating up..especially if your running a higer stall converter like i am. Also a few guys on LS1tech.com have experimented with running 2 external coolers..And it seems that running the coolers in parallel is more efficient than running them in series.
Most aftermarket ATF coolers are sized to be used inline with your current factory ATF cooling. Without an ATF temp gauge for some pre/post fluid temp testing, I would NEVER bypass the factory cooler.
And, I don't care what any rebuilders say. There are just too many variables that occur. Rebuilders also have said not to change your ATF, not to install filter kits, not to use synthetic ATF...... so take their recommendations lightly.
A pan temp gauge will give you the answer, not me or anyone else.
And, I don't care what any rebuilders say. There are just too many variables that occur. Rebuilders also have said not to change your ATF, not to install filter kits, not to use synthetic ATF...... so take their recommendations lightly.
A pan temp gauge will give you the answer, not me or anyone else.
well this transmission company builds many 800-1000 HP automatics, and have many guys on LS1tech that are running very fast times with there transmissions..They do recommend fluid changes..and they do say synthetic is perfectly fine to use. They also give a 1 year unlimited mileage warranty with all there transmissions...even if the car is strictly a drag car. So i feel pretty confident in there recommendations.
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TCI?
Gary,
It would be performabuilt as Travis said earlier.
I have no issues at all controlling my trans temperatures in my 4000lb car with the stock cooling sytem. 3400 stall, 9.5" Diameter. Although the factory cooling sytem on my car has an internal radiator cooler, plus an external cooler. I've added an external filter to the setup. BTW I Run a 160 T-stat.
It all depends on the setup
It would be performabuilt as Travis said earlier.
I have no issues at all controlling my trans temperatures in my 4000lb car with the stock cooling sytem. 3400 stall, 9.5" Diameter. Although the factory cooling sytem on my car has an internal radiator cooler, plus an external cooler. I've added an external filter to the setup. BTW I Run a 160 T-stat.
It all depends on the setup
Travis - OK, thanks. I kind of smelled that it was the transmission rebuilder, not the supplemental cooler mfr.
If it is working in your type of car, great.
But do you really think it will cool better WITHOUT the stock cooler in series, first?
If it is working in your type of car, great.
But do you really think it will cool better WITHOUT the stock cooler in series, first?
I would go with the trans builders recommendations.The higher stall speed converters really heat up the oil. The cooler the oil the longer the trans life .It is not motor oil.
Just my 02 from running with and without the factory cooler. I'm running a 3,500 stall 9.5" Vigillante (rattling POS)convertor on my GN. I have one of the biggest coolers B&M makes.
Without the factory cooler in place, cruising temps were no doubt cooler. But, with lots of low speed stop and go, temps would creep up.
With the factory cooler hooked up and a 160 degree thermostat, trans temps stayed much closer to 160 degrees during idling and slow speed driving.
What I ended up with was a fan/thermostat combo sold by Summit relatively cheap mounted to the cooler and no radiator cooler. Believe it or not, this made a slight difference in engine temps since the factory radiator was marginal already.
Without the factory cooler in place, cruising temps were no doubt cooler. But, with lots of low speed stop and go, temps would creep up.
With the factory cooler hooked up and a 160 degree thermostat, trans temps stayed much closer to 160 degrees during idling and slow speed driving.
What I ended up with was a fan/thermostat combo sold by Summit relatively cheap mounted to the cooler and no radiator cooler. Believe it or not, this made a slight difference in engine temps since the factory radiator was marginal already.
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This can be the case where you're going to be heat soaking both systems. Your 160F thermostat is only sensible if you need 30 more seconds at WOT before you have to let off the throttle before natural overheat. That is, your power output is mismatched with your radiator. To combine the two coolers would subject the rad and transmission fluid to even more overload.
As you observed at low speed, with no airflow over the trans cooler, the temps were not buffered by the (at the time) cold(er) in rad tank cooler. The flow and temp differential in the rad ..coupled with the better exchange rate due to the density of the coolant trumps the stand alone method.
As you observed at low speed, with no airflow over the trans cooler, the temps were not buffered by the (at the time) cold(er) in rad tank cooler. The flow and temp differential in the rad ..coupled with the better exchange rate due to the density of the coolant trumps the stand alone method.
I'm sorry, I meant to clarify but I got lazy. The 160 degrees stat was for the motor so I could run an extra psi or two of boost without detonation. Still, there's a huge difference between the transmission fluid entering the radiator cooler and the coolant temps.
After dumping $3,500 for the trans and another $650 for the convertor, I finally started listening to my builder which was "you can't run an auto trans too cool in the California climate". I have a deep pan which has really helped to reduce the temp spike after a run and two of the biggest coolers I could find. Trans stays around 160 all the time with no real spikes. I've noticed the stall speed of the convertor stays more consistant. I wondered if the viscosity of the fluid could affect stall speed and after this, I would have to say it does have a very small effect.
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And you never approach 195F .even when hammering it?
Yet......
What kind of ^T does your rad have @ 160F ...at 195F ??? Your trans is below 160F?? For how long when driving?
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