steve gravelle Steve, on the 68RFE (guessing you do not have the Asin) when in 6th gear have you varied the speed to see if the rough running goes away? If roughness goes away, its engine related most likely, if it stays and changes with RPM, it could be trans related in that 6th gear. Look around for the gear pack sequence for 6th gear (based on your experience with auto field) and see where they are shared, then see if you can feel the vibration in those gears.

This may sound like a strange fix, but double dose of the Silver bottle of Diesel Kleen for a couple of tanks. This will help the injectors by leaps and bounds.

You may also be running too low of RPM at 60 in double over pulling the camper. Yeah its got enough torque to do it, but not efficient especially if in the mountains, which will result in plugging the DPF because of logging the engine and not getting full combustion. How are your Regen Cycle times? I'm running an iDash (monitor only) in my GM to watch for DPF regens both pulling and not pulling. If you don't have a way to monitor the regen cycles, it might be worth the investment in some type of gauge that will help. I know running our flat(ish) grounds down here, the DPF goes down towing the camper vs running empty.

steve gravelle Steve, Found this:

Reverse - Low/Reverse + Reverse

1st Gear - Low/Reverse + Underdrive

2nd Gear - 2nd Clutch + Underdrive

3rd Gear - 4th Clutch + Underdrive

4th Gear - Overdrive + Underdrive

5th Gear - Overdrive + 4th Clutch

6th Gear - Overdrive + 2nd Clutch

You might want to see if at the same RPM if the truck has the same Roughness.

https://nextgendiesel.com/blogs/tran...tions-upgrades

Joseph, thanks for the thorough response. My instinct is that it is engine related because the transmission has been consistent for close to 80,000 miles, and has been serviced three times replacing both filters and using the recommended ATF + 4. A couple of months ago because of horrible exhaust odor, I removed the EGR valve which was stuck in a half open condition. I ran the truck with the EGR electrical disconnected for a month. It is currently connected. The shop I am going to tomorrow has on their website that EGR is like smelling your own farts. A little crude but accurate. All to be continued. Fortunately we are here in Colorado for 2 weeks at least while a cap is being created for a molar. Hope to head to Baton Rouge, Pensacola, Myrtle Beach and beyond IF diesel fuel is available for somewhat a reasonable price. The land of the free is becoming less so.

Steve, From my intimate knowledge of transmissions (little to none), I do know that fluid changes have caused band and clutch pack delimitation. Stranger things have happened but 80k or 8k on a transmission is can be the same with man made parts. Hopefully the EGR issue helps with your issue. In the mean time, order some https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1 and feed the DPF while pulling. Never hurts.

Just to add BG makes an excellent diesel injector cleaner that really works. https://www.bgprod.com/catalog/diese...ystem-cleaner/. Their BG 44K for gas powered TV is excellent to.

Steve,

You've cued in on the EGR which may still be an issue. 6th gear will be at a higher load/low RPM than 5th gear/higher RPM. The high load condition could be bringing out a defective EGR. Trans related is unlikely but could be torque converter shudder. The truck would need to be inspected to know for sure since all we can do currently is to speculate.

Jim