48RE Performance Rebuild at PATC
2006 Dodge 2500 5.9 2WD 48RE DAILY DRIVER BUILD
When Jim, our Technical Service Director purchased his new truck in 06 we knew it would be a perfect opportunity for us to monitor wear and deterioration under normal driving conditions. With just over 76,000 miles on the clock we could tell it was time for a rebuild. Jim’s use for this vehicle has been nothing other than a daily driver that tow’s a ski boat in the summer, a small task for a 3/4 ton diesel. The vehicle does have a PPE aftermarket programmer set to “TOW” for the added fuel economy but other than an upgraded stereo, is completely stock. His driving style would be best describe as “relaxed”. Upon purchasing the vehicle new he installed the Transgo shift kit, Governor solenoid upgrade and a higher capacity Derale pan cooler. The transmission fluid has been changed along with a band adjustment @ 30,000 and again @ 60,000 miles. So allow me to walk you through our findings:
Up close shot of our upgraded governor solenoid conversion. We use a general motors solenoid that is about 50% larger than the factory one. This can be changed very easily by simply removing the pan and simply removing the 4 bolts seen here. We also incorporate a billet solenoid block to alleviate the issues with cross leaking that is so common.
Below is view of the unit with the valve body removed. If you look closely you will see just how much the factory band anchor set screw is adjusted out, almost to the max position. This band is applied when shifting to 2ND gear and released when shifting to 3RD gear. It is important to make note that the release of the band is just as important as the apply.
If you look very closely you will see that the front apply band is not only burnt but is at the rivets. I would venture to say within about 5,000 miles the rivets are digging into the drum and he then has the added expense of replacing a drum.
Jim decided for the build to use our #4ED brass impregnated Carbon Fiber band. This band is not only lighter with the carbon fiber material (which improves apply and release) but also has a friction material that has a higher friction coefficient. Carbon fiber also dissipates heat at a much higher rate as well.
Quick shot of the Low / Reverse band, as you can see it is practically new. This band is only engaged when in reverse or when you manually pull your shifter down into D1. We will be reusing his.
Below is a good indication of why stock components with “ANY” type of power adders will cause failure. This is the Direct clutches (3RD) and what you see here is evidence of burning on the inside edge more than the entire face of the clutch. This is what we in the industry refer to as “CONING”. Coning occurs when the steels have inadequate strength and deflect causing and uneven apply. This creates a coning of the steels causing both the clutches and steels to not only lose surface area by applying unevenly but also fail much quicker. Coning will also cause excessive heat to generate which is the #1 cause of transmission failure. The only way to correct this is by using a better quality material for clutches and steels.
We knew we had to address the Direct clutch issue, so Jim was excited to use our newest Direct Clutch Red Eagle Power Pack design . The factory Direct clutches have 5 clutches and 5 steels from the factory. We have been using 6 clutches in our 48RE direct drums with much success for years now. Our latest evolution now holds 7 Direct clutches and 6 steels with absolutely no modifications to the factory drum. This is an 40% increase in surface apply area. This clutch also is manufactured with Alto’s highest grade friction paper, giving added friction coefficient. To alleviate the coning issues that are so common the steels are high grade Kolene steels. These steels while also being a harder steel also have a Kolene coating to keep friction and temperature down.
If the Transgo Shift Kit wasn’t already installed, we would have. This kit we feel is an absolute must on all 48RE diesels. There’s a ton of upgrades that come in this kit, not to mention it corrects the horrible shuttle shift that plague these units.
The Dodge front servo, which applies the front band, has a known history of cross leaking. When this occurs not only is the apply of the band effected causing sloppy 1-2 shifts, but the release of the band is effected as well. The servo that Jim chose was our 518RED16, which is 16% larger apply area vs. the factory one. This added apply area will apply and release the band at a much faster rate as well as reducing slippage when engaged. Looking at the picture below (factory one is on the right) you will notice that the sealing surfaces have been improved by having dual o-rings. We really like the way this servo releases the band, reducing the dragging action that occurs when released. We feel like this is a necessary replacement on every gas and diesel build.
Replacing the factory plastic accumulator was a no brainer for us. These are prone to cracking and cross leaking. The Sonnex piece we used is a nice improvement over stock. The picture says it all I think.
Jim also chose to go with the heavy duty Superior band strut and the Power Wedge billet band anchor as well. With the added pressure we are putting on the band, this is good insurance on a problem area that is common with Dodge diesels.
This is a quick snapshot of what everything looks like before we attach the valve body. If you go back and compare from the previous picture upon disassembly you will notice the adjustment screw for the band anchor is set to a more reasonable depth.
We already knew we had to address the torque converter issue. Although he had no signs of torque converter clutch failure we already were aware of what we would find inside. Below as you look at the picture you will see the burnt edge of the torque converter clutch material. This is caused by deflection of the torque converter apply piston. This causes uneven apply of the friction material, as seen in the burnt edges. If you look beside it you will see the Billet torque converter apply piston we use when building our converters. This converter piston upgrade actually achieves several things. The friction material is a high energy Red Eagle racing material that has a much higher friction coefficient than the factory. We also have a much larger surface apply area which allows us more surface area to spread the load, increasing grip (friction coefficient), and lower converter temperatures. The Billet piston allows increased apply pressure to be applied evenly without any concerns of deflection occurring.
Jim also decided to upgrade the stator in the assembly, using our steel Velocistator. This upgrade is perfect increasing efficiency but also reduces transmission temps. Typically you will see a 300-500 rpm drop in stall speed. This is our #8SS, we specifically redesigned the blade count and pitch to improve low RPM torque multiplication. This is also machined to accept Torrington thrust bearings on either side. This stator is a really nice upgrade on any diesel in our opinion. We have also revised the oiling ports.
Driving impressions are wonderful. The shifts from 1-2, 2-3 and 3-4 are all crisps with no lag. We have long corrected the shuttle shift issues and all downshifts are amazing. Though we don’t publish it we did make a dramatic improvement on parasitic loss.