Hi guys just thinking out loud, I am in the process of redoing my transmission cooling system. I am thinking of using the "internal oil cooler" in my new GN1 radiator for a tranny cooler, I am using -6AN Teflon braided hose for the lines and also using an external tranny cooler. The reason for wanting to do it this way is the inlet to the internal oil cooler is much larger than the inlet for the internal tranny cooler. Has anyone done this before ? What do you guys think ?
Internal oil cooler for tranny ?
- Thread starter ikle
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SSedan64, i am no expert but if the ID of the tranny line is larger than the stock fitting on the inlet of the internal tranny cooler don't you think that would be a restriction. I am trying to maximize my current system so I will eliminate any tranny cooling issues, I would think if I go to a -6AN Teflon tranny line it would move more fluid faster and if the inlet port of the internal cooler was the same size or bigger it cool off the fluid better. Just a thought.
The -6 Line is larger than stock 5/16" Line. -6 OD = 3/8" --- AN sizes>>> SMOKEmUP.com
Can't the Fittings on the Rad be changed from Inverted flare to AN?
Faster flow isn't always better, faster flow can = less time for Fluid cooling inside the Cooler. Similar to running a Low Temp or no Thermostat in the Engine cooling system.
Engine Oil coolers have larger Ports/Tubes because Oil is usually thicker than Trans Fluid.
Can't the Fittings on the Rad be changed from Inverted flare to AN?
Faster flow isn't always better, faster flow can = less time for Fluid cooling inside the Cooler. Similar to running a Low Temp or no Thermostat in the Engine cooling system.
Engine Oil coolers have larger Ports/Tubes because Oil is usually thicker than Trans Fluid.
SSedan good point, so in your opinion using the stock oil cooler to cool the trans fluid wouldn't cool any better than using the stock tranny cooler ? Then if I incorporate -6AN lines the fluid would be moving faster in more volume and do to the trans fluid beinng thinner than oil wouldn't cool properly ? What I am trying to accomplish is building a trans cooling system that would handle anything from bumper to bumper traffic to drag racing. Right now I am just running a external cooler with the stock D5 but I am upgrading the TC to a PTC 10" lockup, so I figure I need to upgrade the trans cooling system as well. The reason for me to want to plumb the lines into the radiator is my car runs at 165-170 degrees consistently which they say is optimal temp for the tranny then into my external cooler. What do you think, should I just keep the factor lines, run them through the stock tranny cooler, then into my external cooler and call it a day. Thanks for your help, it's greatly appreciated, ikle.
usetaboost
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If you just plan on driving it in summer weather go through the stock cooler first then the aux cooler. If you are hooking it up for a dd you need to run through the aux cooler first then the stock cooler. This is what I learned on the tru-cool site. They supply the oem with trans coolers and oil coolers
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What I think is you should NOT use the braided teflon line for hot transmission oil at all.
The only GN I know of personally that had this type line used for the radiator trans cooler ended up with a serious burned car when the line split at the core support.
The very fine mist of ATF plus the high air velocity under the hood created a giant blow torch that allowed flames inside the car and caused a massive fire.
After seeing this horrible damage, I removed my braided stainless lines and went back with a custom bent set of steel lines.
I also made sure there were NO open penetration to my firewall.
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Probably did not do the ends correctly on the teflon or too sharp of bends on the installation. Don't cheap out on the brand of hose/fittings either. I use all of Earls stuff, hose is matched to the fittings, sometimes you can run into problems mixing manufacturers, i.e. using one brand of fittings on another manufacturers hoses. Been working fine on my GN for a couple years now. If I ever do an upgrade on fuel lines will use the same stuff. Pretty sure that is what all the E85 guys are using.
Trans Coolers & Hose / Line / Fittings
Using the stock Trans Cooler + External Cooler should be fine for what you're doing. The type Hose/Line is up to you, I prefer Hard Lines over Hoses because of durability but, the Braided Hoses do work well if done correctly. As "Mark" said below mixing Brands can cause problems, the Hoses/Fittings are different sizes & designs Brand to Brand.
The Cooler placement/position depends on what type External/Auxillary Cooler you're using.
Most Stacked Plate type Coolers are made by Long/TruCool and have an Internal bypass like the LPD/LowPressureDrop Coolers so they can be used after the stock Internal Cooler without over cooling in cool/cold weather. A Tube & Fin type Cooler can also be used like this with a seperate Bypass Regulator in cool/cold weather. The LPD Coolers have an internal bypass/self regulating design.
In cold weather bypassing the External Cooler prevents overcooling which allows Condensation to be boiled out of the Fluid.
I also always use the stock Internal Cooler combined with an External Cooler.
Here's why, quote from PATC's site.
"Transmission Cooling: You must have a transmission cooler in your radiator regardless of what someone has told you for the transmission to last. Auxiliary coolers are just that, in addition to. Water cools 32 times better (faster) than air always, period. In the case of air vs. water, there is no contest - water is way better. The transmission fluid comes directly from the torque converter at a much higher temperature than the water in your radiator and is cooled to the water temperature fast. Then it goes to the auxiliary cooler to be cooled far below the water temperature. If you don't need a cooler in your radiator why does GM spend all that money doing so? If you wanted to cool a red hot piece of steel fast would you stick it in water or air, see the point."
Todd
Using the stock Trans Cooler + External Cooler should be fine for what you're doing. The type Hose/Line is up to you, I prefer Hard Lines over Hoses because of durability but, the Braided Hoses do work well if done correctly. As "Mark" said below mixing Brands can cause problems, the Hoses/Fittings are different sizes & designs Brand to Brand.
The Cooler placement/position depends on what type External/Auxillary Cooler you're using.
Most Stacked Plate type Coolers are made by Long/TruCool and have an Internal bypass like the LPD/LowPressureDrop Coolers so they can be used after the stock Internal Cooler without over cooling in cool/cold weather. A Tube & Fin type Cooler can also be used like this with a seperate Bypass Regulator in cool/cold weather. The LPD Coolers have an internal bypass/self regulating design.
In cold weather bypassing the External Cooler prevents overcooling which allows Condensation to be boiled out of the Fluid.
I also always use the stock Internal Cooler combined with an External Cooler.
Here's why, quote from PATC's site.
"Transmission Cooling: You must have a transmission cooler in your radiator regardless of what someone has told you for the transmission to last. Auxiliary coolers are just that, in addition to. Water cools 32 times better (faster) than air always, period. In the case of air vs. water, there is no contest - water is way better. The transmission fluid comes directly from the torque converter at a much higher temperature than the water in your radiator and is cooled to the water temperature fast. Then it goes to the auxiliary cooler to be cooled far below the water temperature. If you don't need a cooler in your radiator why does GM spend all that money doing so? If you wanted to cool a red hot piece of steel fast would you stick it in water or air, see the point."
Todd
usetaboost
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So true. We use plate exchangers at work. The temp difference is very significant. If they didn't work all cars would have aux coolers. It's funny when I hear of people bypassing the radiator cooler and just using an auxilary then they can't figure out why the trans is shot after towing and putting other strains on the trans. I DO know that some stock vehicles would be better off with an aux cooler, one is the trailblazer ss. Have no idea why they didn't get one????
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Mark Hueffman - Owner
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Personal experience, bypassed internal cooler altogether on my GN. Using the big B&M cooler with fan and also have a temp gauge, no problem keeping temps low. Have it mounted horizontally as well so not getting optimum air flow either.
Had a 78 1/2 ton GMC pickup long ago that I converted from a 3 speed column shift manual to a Turbo 350. Just threw an external cooler on it in front of the radiator. Obviously the stock radiator in that truck didn't have the internal cooler and money was real tight back then so didn't want to spring for a new radiator. That poor truck towed my Chevelle on a trailer from CT to the Street Machine Nationals in Springfield ILL a couple of times and when the Nats were moved farther west to DuQuoin ILL we went there too. Truck never missed a beat. Back then I never monitored temps but trans fluid never burned and trans never slipped.
Not stating that you SHOULDN'T use an internal cooler just saying it has worked for me.
Oh, and as far as the original intent of using the OIL cooler instead of the TRANS cooler, no reason why it wouldn't work but finding the adapters to go to AN 6 is hard.
Had a 78 1/2 ton GMC pickup long ago that I converted from a 3 speed column shift manual to a Turbo 350. Just threw an external cooler on it in front of the radiator. Obviously the stock radiator in that truck didn't have the internal cooler and money was real tight back then so didn't want to spring for a new radiator. That poor truck towed my Chevelle on a trailer from CT to the Street Machine Nationals in Springfield ILL a couple of times and when the Nats were moved farther west to DuQuoin ILL we went there too. Truck never missed a beat. Back then I never monitored temps but trans fluid never burned and trans never slipped.
Not stating that you SHOULDN'T use an internal cooler just saying it has worked for me.
Oh, and as far as the original intent of using the OIL cooler instead of the TRANS cooler, no reason why it wouldn't work but finding the adapters to go to AN 6 is hard.
