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ATS 48re Transmission and Triple Lok™ Torque Converter
By Lance Clifford

People have asked me, “Why would you want to upgrade a perfectly good working transmission that is still under warranty?” The answer is simple - to make it more durable and dependable! I have never been too confident in the strength of OEM automatic transmissions. My confidence level has been lowered even further by the fact that I tow heavy loads frequently and need to add power to my engine to facilitate my towing. From my perspective, it is not a matter of “if” my transmission will fail, but rather a matter of “when” my transmission will fail. The “when” is what concerns me. My warranty isn't going to do me any good when I need to be at a pro national rock crawling event in 12 hours, and I'm stuck on the side of the highway in the middle of the Nevada desert!

After doing some research, I called up Clint Cannon, owner of ATS Diesel Performance in Wheat Ridge, Colorado. ATS Diesel Performance is highly regarded as one of the top transmission shops in the country. Clint surprised me by saying that the number one cause of transmission failures is due primarily to failure of the stock torque converter. “Factory torque converters simply aren’t designed for the extreme use to which we subject our diesel trucks,” he says. After discussing with Clint my needs for more power and heavy towing, he suggested a Stage V upgrade, which includes an ATS TripleLok torque converter, an ATS Commander, ATS high performance valve body and transmission, along with a billet input shaft.


The inside of a stock Dodge 48re torque converter. Note the single clutch disc (upper left).

The First Critical Piece: The Torque Converter
The torque converter in an automatic transmission has always been somewhat of a mystery to me. Perhaps that is because it is welded shut! Clint was kind enough to give me a primer course in torque converters.

Torque converters are used in automatic transmissions to take the place of the clutch found in a standard shift transmission. The torque converter allows the engine to continue running when your truck is stopped. The torque converter also transfers the torque from the engine to the transmission, hence the name “torque converter”.

To help understand the principal behind a torque converter think of a fan that is turned on and blowing air into another fan which is unplugged. If you grab the blade on the unplugged fan it will stop turning, but as soon as you let go of the blade it will begin to speed up again until it is spinning almost as fast as the powered fan. A torque converter works the same way, but instead of blowing air it is pumping ATF (automatic transmission fluid). The two fans inside a torque converter are the impeller and the turbine.

The impeller is welded directly to the torque converter cover. The torque converter cover is connected to the engine´s crankshaft and turns at engine speed. The turbine is inside the torque converter housing and is connected directly to the input shaft of the transmission. As the impeller pumps ATF into the turbine, the engine´s power is transferred from the impeller to the turbine via ATF, and the turbine transfers power to the transmission via the input shaft. The stator is located between the impeller and the turbine and is critical only during slow speed acceleration or acceleration from a stop when the impeller and turbine are turning at very different speeds. The stator captures energy from the ATF that the turbine isn´t using and redirects this energy to increase engine torque (torque multiplication). The shape of the veins and the spacing between the veins determines how fast and efficiently you get power to the ground. 


The ATS torque converter has the patented Triple Lok™ three disc clutch for extreme duty, and solid lockup.

What is torque converter lock up?
Fluid coupling between the two sides of a torque converter results in slippage of between 2 and 8%. Slippage is wasted energy and decreased efficiency. To increase efficiency, most automatic transmissions also have a lockup clutch (aka, torque converter clutch). In a stock transmission, as the speed of the vehicle nears 40 miles per hour, the highly pressurized transmission fluid is channeled through the transmission shaft and activates a clutch piston. A system with absolute lockup results in 100% efficiency: all the energy of the engine is being transferred to drive shaft with no slippage. It remains this way until the vehicle slows below 40 mph, at which point the clutch piston disengages and fluid coupling resumes.

The degree of lockup is highly dependent on the clutch pad surface area and line pressure. ATS utilizes a three clutch pack design in their TripleLok™ converter which provides the longer wear associated with increased surface area without the need for higher line pressure and additional hardware. The result is three times the holding power of traditional single disc converters (i.e. you can pull heavier) and the converter is more durable so it will wear longer and be more reliable.

The Next Phase: High Performance Valve Body and TripleLok Commander™
Now that the torque converter is built to handle the power, modifications to the valve body can be made to increase performance. The ATS high performance valve body allows the torque converter to lock up in first, second, third and fourth gears maximizing efficiency in all gears. In addition, the valve body will maintain lockup during a shift from fourth to third, which is especially nice when utilizing an engine brake. When coupled with a TripleLok™ Commander, the driver can electronically control lock-up at speeds between 15 mph and 30 mph instead of the factory specified 40+mph. The result is better mileage and performance due to increased time in lock-up with 100% efficiency.

Final Phase: High Performance Transmission and Billet Input Shaft
To increase pulling capability while in overdrive, ATS adds more overdrive clutches and more high/reverse clutches to handle the higher torque loads. Heavy-duty bands and band struts are used and better oiling is provided to the overdrive planetary gears to enable towing in overdrive. The result is a transmission that can handle modified engines up to 500 horsepower and loads over 18,000 lbs. For extreme use like pulling or dragging competitions, increased power up to 600 horsepower, or regular hauling of larger loads, up to 30,000 lbs, a billet input shaft with a hardened clutch drum is necessary.

The Install

20031207059.jpg I made arrangements with Clint Cannon, owner of ATS Diesel Performance, to have his staff of technicians tear into my new Cummins powered 2003 Dodge Ram 2500. The truck still had the paper plates on it when I arrived at ATS in Wheat Ridge, CO, on Tuesday morning.
20031207045.jpg "Jake" welcomed me as I walked in the front door.
20031207058.jpg As you can see, ATS is a large, busy shop! They have 8 service bays, and they were filled to capacity with diesels of every make and model every day I was there. These guys don't mess around!
Clint put his crew to work right away on my truck. I have to admit, I was a little nervous tearing into my brand new baby. I mean, if it ain't broke, don't fix it, right?
20031207067.jpg
Here is the stock 48re transmission. While it worked well for the whopping 4,000 miles it was in the truck, I knew that something bigger, stronger, and more "colorful" would be even better.
20031207071.jpg

Eric was the technician that would be tearing my new truck apart. After spending a few days watching Eric tear my truck apart and put it back together, I would trust him with my newborn child... If I had one.

Here Eric drains the fluid from the stock tranny and removes the tranny pan.

20031207073.jpg While the fluid was draining, Eric began unbolting the rear driveshaft. I think it's awfully lame that DC does not paint the driveshafts from the factory. With only 4,000 miles on the truck, the driveshaft looks 10 years old.
20031207082.jpg Once the rear driveshaft is removed, Eric removes the crossmember holding the transfer case and tranny in place. With the crossmember removed, the front driveshaft is removed.
20031207091.jpg Once the crossmember and 'shafts are off, the transfer case is removed.
20031207092.jpg Behold the chain driven (YUCK!) part time New Process 271.
20031207096.jpg Unplug a few wires, remove the shifting linkage, and out comes the still new looking transmission. Right about now I am asking myself, "Self, what the hell did you get yourself into?"
20031207098.jpg The stock torque converter is removed from the tranny and put on the lathe to be cut open and inspected.
20031207099.jpg With only 4,000 miles on the truck, the fluid in the stock torque converter still looks new. The inside of the converter looks just as good.
20031207100.jpg The transmission was then handed off to Fred "the tranny guru", who would be doing open heart surgery on my transmission. And when I say open heart, I mean it. I don't think he left a single part of this thing untouched!
20031207102.jpg Fred begins by removing the valve body from the transmission. He will completely gut and rebuild it with new high performance ATS parts.
20031207108.jpg The pump is removed from the front of the transmission.
20031207111.jpg The input shaft of the transmission is a known weak spot in heavy towing, and high horsepower/torque conditions. The input shaft is going to be replaced with a billet 300m chrome moly replacement.
20031207116.jpg Here is the stock input shaft and front gear (bottom) and the new billet 300m input shaft and front gear (top). The shaft is made out of one of the toughest materials around - the same stuff aircraft landing gear is made out of!
20031207120.jpg Here is the new front clutch pack.It contains 5 clutches instead of the factory 4. The rear clutch pack gets 6 clutches vs. the factory 5.
20031207121.jpg ATS replaces the factory plastic accumulator piston with a metal one.
20031207122.jpg Fred now tackles the valve body, completely tearing it down to nothing.
20031207123.jpg Oh my God! Will my valve body ever live again? Look at that bucket of parts! I have to give it to these guys - That pile of parts resembled the world's largest jigsaw puzzle to me. I respect the guy who can put it all back together and make it actually work!
20031207126.jpg Now that it's all torn apart, it's time to hot tank everything and begin putting it back together with beefier parts.
20031207131.jpg The new 300m input shaft and gear are inserted back into the clutch assembly.
20031207132.jpg The unit can now be placed back into the tranny housing.
20031207137.jpg Install a new gasket, and the pump can be put back into place.
20031207140.jpg Back to the valve body - Now that it's clean, it's time to reassemble. Fred has all of his parts meticulously laid out on the table.
20031207144.jpg Fred drills a few holes here and there into the valve body. He tells me this is to aid in lockup.
20031207146.jpg Fred takes some of the valves to the sander, to also aid in lockup.
20031207147.jpg Inserting the valves back into the body.
20031207149.jpg New check balls are put into place.
20031207150.jpg A new ATS lockup separator plate is used to aid in lockup.
20031207152.jpg Wow, he really can put it back together! It's starting to look like a complete valve body again.
20031207160.jpg Doing the final touches to the valve body before reinstalling it back into the transmission.
20031207163.jpg Reinserting the valve body back into the transmission. Another cool feature is that ATS replaces the manual valve in the valve body to allow fluid circulation while the vehicle is in park. Normally while in park, there is no fluid circulation, and a transmission can overheat simply by idling for extended periods of time!
20031207164.jpg The tranny gets shot with ATS' trademark purple color scheme. I was assured this is a very cool color.
20031207165.jpg With everything complete, the stock tranny pan is bolted back on. I plan on adding a higher capacity Mag-Hytec tranny pan down the road when I have a little extra $$$ laying around. The stock tranny pan doesn't even have a drain plug.
20031207167.jpg Here she is in all her glory. Ok, so the purple is growing on me!
20031207025.jpg Now that the transmission is ready for action, Fred has Jeff "the dyno man" test the transmission on their in-house tranny dyno. It's mated to the engine, and put to the test.
20031207177.jpg Jeff runs it through a series of tests checking shifting, line pressures, etc. It looks like Fred really does know what he's doing, because the transmission passed with flying colors, and is ready to go back into the Dodge.
20031207178.jpg Before Eric bolts the tranny back into the Dodge, he installs an ATS TripleLok™ Torque Converter. This bad boy has a three-disc clutch pack compared to the factory’s single clutch disc. Don’t be fooled by imitation TripleLok™ torque converters. Other companies are actually painting their torque converters purple to make them look like an ATS TripleLok™! Also, watch out for the cheap three-disc knockoff converters on the market, only ATS backs their converters with a 3 year, 100,000 mile no power limit warranty. If it doesn’t have TripleLok™ etched on the cover – it’s not a TripleLok™.
20031207181.jpg With the torque converter in, it's time to put the tranny into place. Eric uses a tranny jack to carefully put the transmission into place. If he was a real man, he'd muscle it in instead!
20031207194.jpg Ok, I take that back... He muscles the transfer case in like it was nothing.
20031207196.jpg With the front driveshaft bolted back on, he bolts the crossmember back into place, and removes the tranny jack out of position.
20031207197.jpg That rear driveshaft a little too much for you there, big guy? Maybe you need a driveshaft jack? Just kidding...
20031207198.jpg With everything back where it belongs, I realized that I've really grown fond of purple. I can't wait to test this bad boy out!
20031207203.jpg One final step - Eric installs the in-cab TripleLok Commander™. This nifty little unit controls when the torque converter locks up and when it unlocks.

Driving impressions
Once the transmission was installed, I could not wait to drive this thing! While the stock tranny was decent, it had a sluggish feeling, and shifted like a Lincoln Town Car - not a real truck. I also didn't like the way it didn't lock until 40+ mph. I wanted a more “manual” feel.

When I went for a test drive, Clint went along to show me how to operate the TripleLok Commander. The Commander has a green LED that lights up when the torque converter locks up. Clint put the Commander at its lowest setting (so the converter will lock up at low speed) and we took off. At about 15mph I could feel the converter lockup, and the green LED came on. Too cool. As I accelerated, the transmission made smooth, firm shifts. This finally felt like a truck! With the Commander at it's lowest lockup setting, the torque converter would stay locked as I decelerated all the way back to idle, and would actually bog down the motor as I slowed to a stop. The Commander can be disengaged at any time by simply pushing the power button on the front of the module. This will cause the transmission to shift and lock up like it did from the factory. I found this very useful in comparing “before and after” scenarios.

After playing with the TripleLok Commander, I've fallen in love with it. Towing is an absolute dream, and daily driving is much more enjoyable. I can't say enough about how this combination of parts has transformed my truck into a much more controllable, and driveable truck.

No matter what type of diesel truck you drive, I would highly recommend you give ATS a call if you have an automatic transmission. For a reasonable price you can get a product that is exponentially better than the stock, and in my opinion worth every penny. I can now easily climb grades while pulling a heavy load without the worry of being stranded. Worth giving up my factory warranty on the stock tranny? You bet! ATS offers a full 100,000 mile warranty on their transmission upgrades; a warranty unmatched by their competition (just like the quality of their tranny). Give ATS Diesel Performance a call. You won’t believe what a difference they can make.

Contact

ATS Diesel Performance
4295 Kipling St.
Wheat Ridge, CO. 80033
Telephone: 303.431.7973 Toll Free: 800.949.6002
Hours: M-F 8am - 6pm MST
www.atsdiesel.com
info@atsdiesel.com