New to me 40SKQ

[laveydude26]

Thank you to everybody who responded. I must say I’m a little worried about this whole thing, hope I did the right thing. At some point you can read to much on different threads and forums, and have too many people complaining about certain things, and drivability issues. I’m just gonna have to hope for the best.
As far as general repairs and maintenance to the coach it’s self, that doesn’t worry me. Im very handy in that respect. It’s the chassis, motor and drivetrain is concerns me the most.
If anyone has more time in-depth information please feel free to PM me.
Thanks again!!!!
Steve

[YC1]

Just watch your engine and tranny temps as you climb. If you have the "medallion system", with the rows of buttons to select things like psi, fuel, temps, etc. just put in on the temps monitor.

The temps will climb on a hill to 210 easily. If trying to creep past that just get your foot out of it and drop a gear with the shift panel by pressing the down button.

Don't be in a rush to be the first one on the top of the mountain, you won't be.

I haven't climbed a hill in over two years now unfortunately.

You are on a steep learning curve here. Pun intended. Take things slow. It is an amazing rv but all of them need constant love. If you are not tweaking on them you missed something.

Being handy with tools, a voltmeter, and a checkbook is important with any rv.

Safe travels.

[777 Driver]

Originally Posted by laveydude26

I have one very long hill to climb coming out of Palm Springs to Arizona. Is there an RPM range I should try and stay in climbing this hill?

Your ISL 400 has peak torque (1250 LB-FT) at 1400RPM.
Your ISL 400 has peak horsepower (400 HP) at 2100RPM.

Those are easy numbers to remember and are good targets for different occasions.

When you're on a level road, cruising, you should try to maintain your peak torque RPM (1400) in the highest gear (6) for best economy.

When you're climbing a steep grade, maximum horsepower is your goal. As you start up the grade, apply wide open throttle (WOT) and let your transmission automatically downshift as your speed decreases. When you achieve stability (no more automatic downshift), you'll see an RPM closer to peak torque. At that point, manually downshift one more gear and control engine speed with the throttle as close to 2100 RPM as possible. Your speed will be controlled by throttle movement. Don't worry about speed, just keep the RPM's at about 2100 with the throttle and accept whatever speed you've got. The 2100RPM will keep you at peak horsepower and, very importantly, will keep the coolant flowing thru the radiator and the fan running at a high enough speed that you won't have any problem with overheating.

One more important consideration as you breath a sigh of relief when you crest the hill is to control your speed during the descent with a combination of transmission and engine brake. Only use your service (foot) brake intermittently to slow down. Typically, I'd resist the urge to upshift at the crest. Assuming that the downgrade is the same as the upgrade, the gear used for the climb is a good first choice for the descent. Just ease off the throttle as you start to accelerate until you're completely off the throttle. If your engine RPM gets back up to 2100RPM with your foot off the throttle, use your service brake to slow down. You should just apply it for a few seconds to accomplish the deceleration, then take your foot off the brake. Let your speed build up again to about 2100RPM and repeat the service brake application. If you find yourself applying the service brake most of the time, you should downshift to a lower gear. On the other hand, if you find that you're never applying the service brake and you feel like you could safely descend at a higher speed (MPH), manually upshift one gear and see how that works. The goal is to control your speed (MPH) at a comfortable speed while only having to occasionally apply the service brakes.

It's generally accepted that if your speed (MPH) drops below 45MPH, you should turn on your emergency flashers to signal your speed.

Take care,
Stu

[windsorbill]

What Stu said about the peak Horsepower is right on. Keep an eye on the temperature gauge. I usually down shift before the transmission will do it. I'm trying to keep the rpm's right in the 2000-2200 range. I have found that the temperature won't fluctuate as much as when I let the transmission shift itself. The speed going up that hill is whatever it is and don't worry about that.

The hill your talking about outside of Palm Springs (actually Coachella), I'm very familiar with. I've done it when the OAT was 117. Turning off the dash air can help with both power and engine temperature and just run the generator with roof airs. Once you crest it, it's pretty level. As you crest it, don't be tempted to jump right back to 6th gear without watching the temperature gauge. There is a lot of heat built up and you need the water pump circulation even though you're flat and level.

[YC1]

Dang Stu, that is the most elegant and straightforward answer I have ever seen written.

I may copy and paste that in the future.

Be careful to follow his suggestion on using the service brake to slow you down. If you have to do it just a few times you need to slow down and get it into a lower gear.

Death Valley nearly had another victim a few years ago. Had I followed his advice it would not have been a problem. White billowing smoke from the rear brakes and an RV that would not stop is not fun.

Did get it stopped and learned a lot from that and then my life time trucker cousin explained it just as Stu just did. Never rely on your brakes going downhill.