D&W’s clutch casting is made from Eaton’s drawing so it is to the thousandths of an inch identical.
Sealed release bearing
1) Keeps contaminants out at all times
2) Keeps grease in even when it is liquefied due to being stuck in snow or mud. The grease will return to its original consistency as it cools.
Continue to grease the bearing housing as it acts as a heat sink to keep the bearing cool and also runs over onto the bearing sleeve bushings for the input shaft.
Eaton uses a flat shield on the top of their release bearing which can float above the bearing races and still allow contaminants into the ball bearings. They use a grease slinger on the bottom of the bearing housing to push liquefying grease back up into the bearing which will allow liquefied grease to escape out of the top or bottom of the housing when it is too hot. Contaminants can still get in from the bottom.
OE pressure springs
OE Friction
1) SK Wellman is primary supplier to Eaton. Miba is the backup supplier. D&W only uses these two suppliers. Eaton uses ceramic friction on all of its clutches. Ceramic is the most aggressive friction made and is necessary on three and four paddle discs due to the smaller quantity of total square inches of friction surface area than a six paddle clutch. However, six paddle clutches slip more than four paddle clutches. That’s why they require a heavier plate load to stop them from slipping and transfer the energy generated by the engine. Since they slip more, D&W uses Carbotic friction on all of its six paddle clutches as it dissipates heat much better than ceramic friction while maintaining the same coefficient of friction. Carbotic will outlast Ceramic by 10-15% service life in mileage. Carbotic is also made by Wellman.
2) Eaton builds discs to a .450k thickness as did D&W for decades. Three years ago, D&W switched to a .480k thickness disc. Thicker friction material provides the following advantages
A) A greater heat sink due to thicker friction material
B)Increased air flow between the discs keeps the operating temperature lower to increase clutch service life.
C)Thicker discs mean the initial setting of the clutch adjustment to achieve the 1/2” release travel of the bearing will bring the adjusting ring up into the cover casting farther than it would be with a .450k disc thickness. Therefore, the pressure springs will be compressed shorter than the Eaton product thus maintaining spring pressure (plate load) longer throughout the life of the clutch. In other words, as the clutch wears over time, the pressure springs elongate to keep the pressure plate within 50-60k of the discs and as they elongate they lose pressure. So what was a 4000 pound plate load will lessen to 3900, then 3800 pounds, etc. over time. .480k discs help prevent a future slip condition.
Dual grease fittings
Allows our clutches to be used in multiple applications including Mack or Volvo. If the pilot bore of the flywheel accepts the spring cage of the disc and the torque rating of the clutch is correct for the engine horsepower, clutches can be substituted between different makes of trucks.
Improved adjusting mechanism
1) Still a press, turn and snap back into place mechanism mechanics prefer.
2) Longer gear teeth on our adjuster always stay in full contact with the adjusting ring gear teeth inside the clutch. Eaton’s gear teeth are shorter sometimes resulting in only 70% contact causing teeth to break.
3) Gear drive is hydraulically pressed onto a tapered shaft whereas the Eaton version has a dow pin holding its gear onto the shaft which can shear and the clutch adjusting ring can spin freely resulting in disc lock up and the inability to shift gears and a downed truck.
4) Thicker mounting plate is less likely to bend.
5) Only our locking plate depresses, not the entire adjusting nut, shaft and gear. The Eaton adjuster can wear under the nut and can result in a not locked condition even though the mechanism snapped back to the presumed locked position.
Improved disc technology
D&W has made 7 changes to our disc technology that has proven to improve our disc service life in dynamometer and real world testing by 30% greater life than our competitions’ products.
All cast clutches have the PT2540 clutch brake “shim” in the box to make up for flywheel machining variances at installation.
D&W’s Sure Shift clutches are a true “Easy Pedal” design with strap driven pressure plates just like Eaton’s clutch.
American made = 51% or more of finished product is made from raw materials, completed components, labor and packaging in the U.S.
108925 or 108391 part number Eaton clutches were the original style easy pedal clutches. They changed over time to the dual grease fitting bearing housing as well as from the retractor spring style pressure plates with guide slots to the strap style pressure plates without guide slots.
208925 and 208391 part number Eaton clutches were the same as the strap driven pressure plate style 108925 and 108391 clutches but with the following additions:
Three grease fittings per bearing housing
The flat disc shield in the top of the release bearing housing
The grease slinger in the bottom of the release bearing housing
Wider wear pads on the ear of the bearing housing where the fork contacts it. The fork is the same size as it was so no benefit achieved except for the larger fork used in Cascadias with Solo self-adjusting clutches.
“Increased” grease capacity within the bearing housing. (In the wider ear where the fork contacts it = Misleading).
New adjectives used to describe the friction material which did not change.
Positive separator pins in the center plate lugs (ears) to gain equal release between the discs. Centrifugal force already achieves equal release between the discs. These pins can bulge or bur at installation causing release issues.
Two year warranty. Eaton seems to deny 99% of aftermarket clutch warranty claims unless the clutch was installed at a dealership. Increasing a warranty period is inconsequential if all are denied anyway.
308925 and 308391 part number Eaton clutches have all of the 208… series attributes but now also include a groove within the release bearing sleeve to allow grease to flow directly to the brass bushings in the sleeve for lubrication of the input shaft. Eaton also strapped the center plate to the clutch housing trapping the pressure plate side disc. The installer must pick up two components at installation instead of four, one weighing 130 pounds which is a deterrent to a small shop without a clutch jack. This prevents the installer from inspecting the pressure plate side disc for damage from the input shaft (burred splines or “dished” disc) if the transmission does not slide into place perfectly on the first try.