Project TowBoat Stays Alive With Huge BD Diesel 68RFE Trans Upgrade

As the popularity of the 6.7-liter Cummins-equipped Rams increases, the number of owners looking to modify them do as well. Unfortunately, some truck owners find the weak link of the combination, the 68RFE. This six-speed automatic transmission never started its journey of life as a dependable option. Even with very little power added, like custom tuning, you can experience a transmission failure due to burned-up overdrive clutches.

Project TowBoat features tuning and compound turbos that inevitably upped the horsepower and torque level which could potentially cause some issues. When the truck was purchased, it was said that the engine and transmission already had good parts in it. The truck survived long trips with a heavy trailer, a little abuse here and there, and so much more.

After thousands of miles of use, and honestly, not really being abused, we were starting to feel some wear and tear. There was slippage occurring when in the overdrive gears and since we take this truck thousands of miles from home, we could not risk being stranded. We know that the overdrive clutches fail, after all, they are a wear item and a common issue with the transmissions.

What Do We Do?

TowBoat’s transmission was experiencing issues and we were up in the air about which direction to head. We had to decide, do you pull the transmission, take it somewhere for them to tear it down and install new parts, or just install a new, upgraded unit? We have been dealing with BD Diesel for years, and after seeing their engineers come up with ways to further strengthen these transmissions, the decision was made to upgrade altogether.

With the company’s trade-in program, we were able to exchange our old, worn unit for a new one. The dependability of any transmission is absolutely critical and with this new ready-to-go 68RFE, we have a clean bill of health and a dependable driveline. Before we dig into how we got the transmission in there, and the rigamarole of setting up one of these, let’s talk about what you get with a BD Diesel 68RFE.

From our research done with other Ram owners, BD’s 68 is one of the industry’s best. Like you may have read in earlier articles, BD has addressed common failures associated with these transmissions and we feel safe using their builds. Per BD, burnt overdrive clutches are a thing of the past. They utilize custom, billet QT100 reaction plates, longer “Big Stack” spline overdrive shafts, and 16 frictional surfaces. Before being shipped, each 68 that is built in-house is pressure tested to withstand 250 PSI of line pressure for ultimate torque-holding capacity.

With a truck that sees a decent amount of horsepower and torque and also gets worked daily, this is what we like to hear. Let’s talk about the rest of the features. Each unit includes:

Features

  • Hard-Anodized valve body with new solenoid pack
  • Custom-bonded gasket valve body separator plate increases line pressure while stopping internal cross leaks
  • Heavy-duty cam and roller design low reverse one-way clutch
  • New 4C billet spring retainer
  • Steel girdle added to 2C piston to allow for more clutches and broader apply area
  • BD Durabale QT100 pressure plates allow for increased clutch counts and reduce deflection and distortion within the clutch drum
  • Overdrive and 2C clutches both increase 33-percent
  • Custom “Big Stack” overdrive shaft
  • BD reinforced accumulator plate
  • TCC limit valve machined and sleeved to address high wear area within the pump
  • BD deep-sump oil pan adds extra fluid and cooling capacity while reducing case flex
  • BD ProTech68 pressure control module ramps up line pressure to 250 PSI using MAP sensor to input load and adjust the pressure required
  • Available with a billet input shaft

Per BD, 9 hours is the recommended install time. With a new unit going in, you’re receiving a 36-month, 150,000-mile warranty. BD made it clear, the warranty was only covering normal use, race abuse is not covered. Also, please note that only a BD Diesel torque converter is to be installed in this transmission. The use of a third party or OE converter will invalidate the transmission warranty. To stay within the warranty contract, in goes a BD 68RFE flexplate and Proforce 3D torque converter.

New transmission on the jack getting prepared to go into its new home.

These trucks, even slightly modified, have enough power to crack or even shatter the stock flexplate. Proven to handle 2,000 lb-ft of torque, the BD flexplate features twice the material of a stock one and they are forged billet. They are even precision-balanced and SFI approved pieces. Coated with black oxide means they are corrosion resistant and prevent hydrogen embrittlement that causes that cracking. A bolt-in, replacement flexplate like this is great for racing, towing, or stock applications.

The proper torque converter is critical. This is what sees and applies the power your engine makes, sending it to the ground. With BD’s ProForce 3D converter, we shouldn’t see any balancing or warping issues. They’ve designed a converter cover that increases strength while maintaining height specifications. With the self-centering trapezoid clutch teeth design, the clutch packs ensure proper alignment and less wear which results in longer converter life.

Other features include HD springs that absorb the shock of engagement, thrust bearings, cast stator design, new sprag components for durability, furnaced-braze turbine fins for improved fluid coupling, and a reduced overall weight of 12-pounds over other options.

Out With The Old, In With The New

We took the truck to Scheeter Auto & Diesel for the teardown and up on the lift it went. The driveshaft came out, the transfer case and transmission crossmember were loosened, the transmission jack went underneath for support, and out it all came. Taking it out seemed like a pretty easy chore.

Once the necessary parts were removed, it was time to prepare the new transmission. After we swapped some plugs and linkage over to the new one, including our transmission pressure gauge adapter kit, it was ready for installation. You may be wondering why a pressure gauge is necessary at all. The 68 has a CRITICAL relearn process, and pressure checking these once installed must be done. Now we have a place to connect a wet gauge to verify we’re within specification.

We decided to attach the transfer case to the transmission and put it all in at once.

We separated the transfer case and the old transmission and got it mounted to the new transmission out from under the truck. Once we persuaded it into its new home, everything began going back together in reverse. Reinstalling the crossmembers, inflow and outflow lines, and getting the new torque converter tight to the flexplate, we were ready to set it down on the ground.

We began filling the transmission with fluid, making sure we didn’t move the truck because like mentioned earlier, we have to verify the pressures are correct. Once it was topped off, it was time for the relearn.

Teach It How To Work

Unfortunately, these transmissions are electronically controlled and you have to work together (you and the electronics) to make sure it lives a long time. The transmission came with an easy-to-read instruction manual about how to do this, and BD also provides a link to its YouTube channel where they walk you through the entire process.

“This relearn procedure resets the adaptive mode of the transmission and recalibrates the shift timing,” said Christian Roth, BD Diesel vice president. “Not doing this relearn correctly can lead to premature transmission wear or even catastrophic damage. If you have just installed the 68RFE, it is imperative to initiate the quick learn before driving it.”

There is a procedure to all of this. Before you just hook up to a scanner and have your way with it, there are a few things that need to be addressed. The transmission fluid level must be in the operating range and above 60-degrees, and there cannot be any fault codes in the TCM. If you’ve confirmed these three things, you’re okay to move forward.

“Not all scanners have the ability to perform a quick learn. Scanners that do, are Chrysler WiTech, Snap-On Modus, and AutoEnginuity. You must have one of these to perform this quick learn,” Christian explained. “You must clear the DTC’s before moving forward. If they persist, please fix them before moving on.”

Once you’re clear, you can initiate the quick learn. The scan tool will ask you to follow the prompts, moving the shifter from different positions as it is learning how to function. For us, this only took a few minutes. Once complete, it is time to drive the truck. However, this doesn’t mean it is ready to “drive”. You must follow the instructions and start with light throttle slowly progressing up to heavier throttle.

Unfortunately, we ran into a snag during our learning process. After a very long diagnostic period, we found that both batteries in this truck were showing 12.67-volts. The battery test uncovered that these low-output batteries were the reason for the shown codes. Once the batteries were replaced, things were up to par.

While driving, you should see the scan tool reading CVI values of desired line pressure and actual pressure. These two values need to be within a few PSI of each other. Also, the wet gauge mounted on the side of the transmission should also be pretty accurate to both of these values. The drive learn process requires shifting up and down through the gears until shift quality improves and becomes consistent.

At first, you want to drive with a very light throttle because the transmission is not ready to hold any kind of power. “Find a quiet stretch of road where you can safely start and stop repeatedly. Get to fourth gear with roughly 15-percent throttle, and repeat this until the shift quality is up to par and consistent,” Christian said. “Repeat this process again at 25-percent throttle, 35-percent throttle, and again at 50-percent throttle. By this time, the transmission should start to feel normal.”

How Are Things Now?

We’ve been able to load the truck down and take our race trailer and truck anywhere we need to go.

After verifying the pressures were within specifications, we wasted no time to get this truck back on the road and let the transmission learn our driving habits. Daily driving, towing the race trailer, Friday night fun, etc., the transmission hasn’t skipped a beat. Since the installation, we have put two or three thousand miles on this transmission and it has never been better.

Firm shifting, more pronounced lockup engagement, and it honestly feels a bit peppier. I think the old transmission was facing more damage than we could really tell because this fresh one is really putting the power down to the ground and I can tell. With the 2022 race season approaching, and with potential rough terrain incoming this winter, we know this truck will be able to be out there on the road with no issues at all.

Huge shoutout to BD Diesel Performance for creating a problem-solving piece. If you’re out there looking for a replacement transmission, or if you “know a guy locally”, save yourself some time and money and check out BD’s replacement. There are many options out there, so be sure you know what you’re buying before you pull the trigger.

For more information about BD Diesel’s 68RFE program, or any of their other products, head on over to their website here.

 

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About the author

Artie Maupin

Artie Maupin is from Southeast Missouri and has an extreme passion for anything diesel. He loves drag racing of all kinds, as well as sled pulling competitions.
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