No need to double clutch
From your link
http://www.roadranger.com/ecm/idcpl...As=0&Rendition=Primary&&dDocName=RR_TRDR-0150
“Models in this series provide six forward speeds and one reverse, and are shifted as you would shift any synchronized manual transmission. Follow the simple 6-speed shift pattern.”
“Upshift
In the following instructions, it is assumed that the driver is familiar with operating heavy-duty trucks and tractors, and can coordinate the shift lever movement and clutch pedal to make smooth gear engagements while upshifting or downshifting.
1. Depress the clutch pedal, move the shift lever to next desired speed.
2. Release the clutch pedal.
3. Accelerate.
4. Continue upshifting.
Downshift
In the following instructions, it is assumed that the driver is familiar with operating heavy-duty trucks and tractors, and can coordinate the shift lever movement and clutch pedal to make smooth gear engagements while upshifting or downshifting.
Note: Although the transmission’s first gear is synchronized it is advised that a down- shift into first gear be completed at a very slow vehicle speed to prevent engine overspeed.
1. Always use the clutch when downshifting from gear to gear to prevent prema- ture synchronizer failure.
2. Depress the clutch pedal, move the shift lever to next desired speed.
3. Release the clutch pedal.
4. Slow vehicle.
5. Continue downshifting.
Yes they did give instructions on how to double clutch but no place did they say you ALWAYS have to they actually give instructions to the contrary.