Brenda,

All I can tell you is what we have been told about the way WE should approach mountain passes with OUR equipment.  I suppose most of it applies to motorhomes and other tow vehicles, but a lot depends on engines and equipment.

Anyway, here goes.  In terms I can understand. 

On long or steep inclines we were told to take the truck out of Drive (overdrive) and find the gear that allows the truck to fall into it's sweet spot which should be somewhere between 1800 and 2200 RPMs on the tachometer.  Watching the tachometer is key to know whether to shift to a higher or lower gear.

I'm sure that "sweet spot" differs for every type engine, so you might have to ask around for what it would be on your motorhome.

But no matter what, the engine can only do what it can do with the load going uphill.  Keep an eye on all the gauges and pull over to let things cool down if you need to.

Downhill, it depends on the grade and the length of grade.

Assuming the steepest, longest grade, we want to start down slow and in a lower gear to keep from using the brakes as much as possible.  We don't care what anybody behind us is doing.

As we continue down, if the RPMs get too high or we feel we are going too fast, we are to hit the brake hard for a second or two to lower the speed about 10 mph (we don't want to "ride" the brakes).  We want the engine to hold back our speed as much as possible.

We are to repeat that process all the way down until we reach a comfort level.  Of course we are to watch the brakes for signs of overheating (smoke, or lack of responsiveness).  If we see or feel those signs we are to pull over if possible and let everything cool.

That's the information we have gotten from various sources.  We will let you know how it works in the next few days.   

Hope you manage to get here before we leave.    

Last August at an FMCA rally in Charlotte, NC I asked a Cummins rep what was the proper method for steep inclines driving a Class A DP.  He told me to just leave it in drive and put the pedal down.  He said you can't lug a diesel engine and that you don't need to keep the RPMs up like in a gas engine.  Of course, coming down we had an exhaust brake which worked well. 

I didn't get to test this advice as we were pretty much out of mountain driving by that time, although I had been using the exhaust brake and really trusted that. I never had to shift to a lower gear on some long downgrades.

I remember reading a post on another forum on this subject and the writer was relating a problem he had with overheating brakes on a long mountain downgrade.  He said he hadn't trailed that much smoke since being hit by anti-aircraft fire in his fighter jet over Vietnam!  Obviously he came out OK in both cases.

Unfortunately Cummins isn't the only manufacturer involved in climbing or descending a pass. What Cummins said about the engine is true however, keeping the engine RPM up when ascending a pass also keeps the transmission fluid flowing at a rate which will keep the tranny cool. Also when descending a grade the braking techniques are different depending on the type of brakes your unit has. Hitting the brakes hard for short bursts is fine for disc brakes but not so good for the old shoe style brakes. Since shoe brakes are encased inside a brake drum the majority of cooling is through contact with the drum. When descending with shoe brakes one should use a different philosophy than discs. Shoe brakes should be used to keep you from speeding up rather than slowing you down. I know that doesn't sound like much but it makes a huge difference in how much heat is generated and how much heat is dissipated. Also descending the hill in the same gear in which you climbed the grade ensures that your speed doesn't get too much for the brakes to handle. 20 plus years of driving an RV, both gas and diesel, in the mountains of Colorado has proven the above to be true. It would also be good to remember that this isn't a race to see who can get to the top first. There isn't anything macho about overheating an engine, transmission or brakes in the mountains. It can be very deadly! Respect the mountain and your rig. Take your time or you may not have any more time to take!

Is there a "dummies" book or online website that someone can point us on understanding towing techniques? My husband and I have purchased our first truck (diesel) and fifth wheel to use for extended travel. We've got the truck, are reading the 2 manuals and awaiting the rig. We'll be taking driving lessons from the RV Driving school and have attended 2 LOW events. Then it is practice...practice...practice. Maybe the truck manuals are sufficient overview but any other helpful reading would be appreciated!