Installing a Transmission Cooler in your TTA
Recently, the TCC solenoid on my TTA began sticking, causing the torque converter to lock prematurely (causing the motor to lug) and also remain locked when I would slow down (causing it to buck on deceleration and occasionally stall!) I did some reading and found this to be a fairly common problem with the 2004R, but a problem that is in the end caused and also aggravated by a hot transmission. So I decided to install a transmission cooler and see if the cooler operating temps would solve my problem. I figured if I got lucky I wouldn't have to drop the pan and change the solenoid. Even if it didn't work, adding a transmission cooler is always a good idea, especially on cars with high-stall converters (which our cars have.) One of my goals was NOT to alter the original hardlines in any way or drill any new holes, so I could easily remove the cooler later.
I ordered up a large B&M stacked plate transmisson cooler from Summit. Installing the same piece in my Chevelle was good for a 45F drop in pan temps when I had the 3000 stall converter installed, so I know it's a good unit. The part number is 70266, it's a 8" x 11" x 1.5" unit with 1/2" NPT inlet/outlet. They do make a bigger one, but it would be hard to fit in the car. You'll see why in the pictures. I also ordered some -5AN tube nuts/sleeves and -5AN to 3/8" NPT adapters from Aeroquip. I also picked up some 5/16" preflared hardline and a 5/16" inverted flare coupler from my local NAPA.
I started by bending the hardlines. (Buy a GOOD bender for this or you'll end up collapsing the tubes. I recommend a Rigid bender, available at most local plumbing supply houses.) I tied into the upper port in the radiator. I bent a hardline to run from the upper port in the radiator to down below the core support, and I also bent another line to connect to the factory upper hardline (using the coupler) and also bent it down to the core support.
Next, I decided where to mount the cooler. I used some aluminum line clamps from billet specialties to clamp to the X-brace in front of the radiator. The upper clamp goes directly to the trans cooler, the lower two are connected to the bottom of the cooler via aluminum straps I fabricated (and neglected to get pictures of, sorry.) Basically, they bolt to the clamps, drop down (see the sharpie outline on the lower air dam) and have holes where I bolted the cooler to the straps. I used nylock nuts on all of them to prevent loosening from vibration. I then bolted the cooler up to the upper clamp and the two lower straps. It holds the cooler securely and didn't require any permanent mods or new holes on the car. It was VERY hard to tighten the top bolt as the plastic duct/shroud didn't give my hands much room. The cooler is actually in contact with the shroud at the top. I wouldn't want to install the next size up cooler as you would either have to slice the plastic at the top, or it would hang so low you'd be at risk of damaging it if you drove into a steep parking lot entrance fast.
I used a 37 degree flaring tool to flare the hardline, and used the -5AN tube nuts/sleeves/couplers so I had 3/8" hose barbs on the end of the hardlines. Notice I put split loom over the hardlines; this will help prevent vibration from rubbing through either the hardlines or hoses.
I used brass fittings on the trans cooler to have 90 degree 3/8 hose barb exits. I then connected the hardline to the trans cooler using 3/8" oil rated hose made by Aeroquip. I use a little dab of teflon sealant on all NPT (pipe thread) fittings.
Start the car and check fluid level. I had to add a little over a pint to bring the tranny back to full because of the additional fluid in the new lines and cooler.
Result? My TCC no longer sticks. The TCC would start to act goofy in ~10 miles of easy driving before; once I installed the cooler it hasn't acted up even after my first test, which was 20 miles of hard driving on a fairly warm day. Moral of the story: A cool transmission is a happy transmission!