Wednesday, August 8, 2018

New Clutch

Last June when going through Canada pulling the 5th wheel, there was a couple of sharp jerks while accelerating up a steep hill (10% grade). This meant the clutch was slipping. I known for a while that there was a potential problem with the dual mass flywheel that Dodge started to use on the 2005 models but only under heavy load. The purpose of the dual-mass flywheel was to reduce transmission noise at low engine RPMs. After that happened, I tried to not push things too hard by backing off if I saw the turbo boost gauge approach 30 psi and downshifting more. There was only the one occurrence on this last trip and it happened once on last summers trip when climbing steep grades in Colorado. The consensus on the Internet forums was that once the clutch starts slipping, it just gets worse. At 19,800 lbs combined weight, we are far from the trucks rated 26,000 lbs so I wasn’t expecting this problem.

I took the truck into the Diesel Doctor, a shop here in Fairbanks that pretty much only works on diesel trucks. I asked about aftermarket clutches and they were amazed that my truck was 13 years old and I was just now getting around to replacing the clutch. I guess that most people who actually used the truck for heavy towing were getting it replaced within the first year. The stock clutch really didn't cut it. They recommended a South Bend single disc ceramic clutch. The truck now has a new flywheel (no more dual-mass flywheel), an organic/ceramic clutch disc, stiffer pressure plate and another hydraulic clutch assembly to handle the stiffer pressure plate. This setup is rated for 475 hp and 1000 ft-lbs of torque and I'm under that. The other option was a twin-disc setup rated for 650 hp and 1300 ft-lbs of torque. The shop didn't recommend that one as it's designed for much more severe use. Such as tractor pulling...

I rode the e-bike down to the shop and picked the truck up last Friday. There was a lot of evidence on the flywheel and pressure plate that the clutch was slipping. And quite a bit of rotational play had developed in the dual-mass flywheel. The clutch pedal is now about 50% heavier and you get a bit more transmission noise at low engine RPMs but nothing annoying. Engagement is smooth. Maybe it'll be different when towing. We'll find out next month. They also noticed that the rear main engine seal had a slight leak. It was easy to change since the transmission and flywheel were already removed. I also had them check for a worn water pump or idler pulley since I could hear a worn bearing noise on our drive north in June. They found a worn bearing on the idler pulley that provides tension to the serpentine belt. The belt was also replaced as it's on the 75k mile service list.

They mentioned a few other things to keep an eye on like the front ball joints and front axle u-joints.


  1. Must feel good to have the truck sorted out mechanically....though I imagine you're a bit more broke now....

    1. One less thing to be concerned about. I must admit that I was wondering about the clutch all winter after I thought it slipped last summer climbing some of your steep grades. No slipping occurred unless you really pushed it.