Community Forums

Old Scout · 09-22-2020, 04:43 PM

To my knowledge there is not data on SilverLeaf on pyro-temps--twisted logic perhaps, but if ISL had the data, you would think SL would capture/report it?????

2upServant · 09-24-2020, 03:12 PM

Doug 427 , I really hope you will take some time to study driving safely on grades up and down. first in climbing a hill your biggest issue is the weight you are attempting to pull up the hill. Your coach should have sufficient power to climb most grades. if you are running a diesel with a temp gauge for your transmission and possibly a pyrometer you want to watch both to insure you don't get things to hot and damage the motor or transmission. the viscosity can change in lubricants if it get to hot and cause all kinds of issues long term. so make sure that the transmission does not get to hot. the pyro will tell you what the exhaust gas temp is. also make sure you watch the engine temp that it does not get to high as you could warp the heads.

Downhill is a whole different ball game. brakes get hot a fail then you are riding a heavy load at speed that can be extremely dangerous. what you describe is an engine brake some times called a jake brake. the idea is to use the engine to assist with controlling speed. these systems work extremely well if you use them properly. I have an engine brake in my truck i leave it on maximum, this assist you when you take your foot off the pedal the engine brake will engage and assist in slowing down the vehicle. the best practice for down hill driving is to get to the bottom safely without burning up your brakes. most steep grades will have a run-off ramp which generally is a big long sandpit which is designed to stop a vehicle by it sinking in the sand therefore slowing it to a stop. best practice if you are going down s steep grade reduce your speed at the top significantly start down the hill in a lower gear you can maintain without over revving the engine. let your engine brake do most of the work. be extremely careful about how you apply your brakes, the more often you use them the hotter they will get. you could warp your rotors and the brakes could get so hot they could actually start a fire. a good rule of thumb is the steeper the grade the slower you want to be starting from the top. using the transmission to assist you from getting to fast so that when you hit the bottom you are still in control and below the posted speed limit. watch some you tube videos about driving in the mountains with heavy loads. be safe out there and enjoy the trip. "white knuckle driving" or an accident can end up being deadly.

vanman250 · 09-24-2020, 03:12 PM

One thing I will say is when you get to the top of the hill and you see the sign that tells you the grade, reduce speed blah blah blah pay attention. Those signs don’t just mean the commercial trucks. I drove a big rig back in the day and RV’s are like Uhaul’s in comparison. I and sad to report I didn’t think an RV was a big deal and headed down the mountain at normal speed. Man what a ride at one point I was boxed in and was considering taking the the run away ramp. Luckily the left lane opened and I made it to the bottom in one piece minus a few pounds of crap. I seen a lot of good advice here.

2upServant · 09-24-2020, 03:18 PM

Old scout,
I am an old school throw back from truck driving for 17 years . watching the exhaust temp transmission temp and rear-end temp were really important when driving mountain ranges

2upServant · 09-24-2020, 03:25 PM

Doug 427 , I really hope you will take some time to study driving safely on grades up and down. first in climbing a hill your biggest issue is the weight you are attempting to pull up the hill. Your coach should have sufficient power to climb most grades. if you are running a diesel with a temp gauge for your transmission and possibly a pyrometer you want to watch both to insure you don't get things to hot and damage the motor or transmission. the viscosity can change in lubricants if it get to hot and cause all kinds of issues long term. so make sure that the transmission does not get to hot. the pyro will tell you what the exhaust gas temp is. also make sure you watch the engine temp that it does not get to high as you could warp the heads.

Downhill is a whole different ball game. brakes get hot a fail then you are riding a heavy load at speed that can be extremely dangerous. what you describe is an engine brake some times called a jake brake. the idea is to use the engine to assist with controlling speed. these systems work extremely well if you use them properly. I have an engine brake in my truck i leave it on maximum, this assist you when you take your foot off the pedal the engine brake will engage and assist in slowing down the vehicle. the best practice for down hill driving is to get to the bottom safely without burning up your brakes. most steep grades will have a run-off ramp which generally is a big long sandpit which is designed to stop a vehicle by it sinking in the sand therefore slowing it to a stop. best practice if you are going down s steep grade reduce your speed at the top significantly start down the hill in a lower gear you can maintain without over revving the engine. let your engine brake do most of the work. be extremely careful about how you apply your brakes, the more often you use them the hotter they will get. you could warp your rotors and the brakes could get so hot they could actually start a fire. a good rule of thumb is the steeper the grade the slower you want to be starting from the top. using the transmission to assist you from getting to fast so that when you hit the bottom you are still in control and below the posted speed limit. watch some you tube videos about driving in the mountains with heavy loads. be safe out there and enjoy the trip. "white knuckle driving" or an accident can end up being deadly.

BobRay · 09-24-2020, 03:45 PM

Things have been pretty well covered here. I just wanted to emphasize a few points.

1. On the way down, don't ride the brakes continuously. If you do that, they won't have a chance to cool down and you risk brake failure.

2. Modern transmissions are pretty well protected by their programming. It's better to maintain a safe speed than to worry about your transmission.

3. The old adage about using the same gear coming down that you used going up is nonsense. One side of the mountain may be *much* steeper than the other.

Canusa4 · 09-24-2020, 03:53 PM

Quote:

Originally Posted by BobRay

Things have been pretty well covered here. I just wanted to emphasize a few points.

1. On the way down, don't ride the brakes continuously. If you do that, they won't have a chance to cool down and you risk brake failure.

2. Modern transmissions are pretty well protected by their programming. It's better to maintain a safe speed than to worry about your transmission.

3. The old adage about using the same gear coming down that you used going up is nonsense. One side of the mountain may be *much* steeper than the other.

Bob, I was going to say the same thing. The Grapevine (between Bakersfield and Los Angeles) is much steeper going South, and much longer going North. And no fun at all when it is snowing! There has been some great advice on this thread. One the of the things I struggle with is worrying too much about slowing down others. I have learned that, if there is a string of semis going uphill at a low speed, I had better get behind them, or risk being stuck in the middle lane, and not be able to get out of the way of the speedy guys.

Dyprosper · 09-24-2020, 03:57 PM

You probably won't have any problems climbing. Build speed before the climb and after that It is what it is!

Going downhill this is what I do and feel very comfortable with it:

1- Most important for me is to get mentally prepared ahead of the decent.After awhile you will build confidence and it becomes easy.
2- I slow to a speed I will be comfortable with prior to starting the decent.Sloooow works best for me. Don't wait until you are going downhill to get your speed down, start slow.
3- Engage the engine brake
4- Most important for me is that I manually work the transmission to maintain the decent speed I am comfortable with. Watch your rpms based on your rigs specs.
5- By doing these things I take pride in usually not needing to use the brakes.
6- I have learned to not worry about any traffic behind me and have found that they understand that I will be going slower.

tjtheoneway · 09-24-2020, 04:12 PM

When climbing a grade I let the Allison do the shifting n I watch the temperature gauge! If the temp starts to climb I shift down a gear n keep the RPMs up around 2500 to 2700 n works for me! When I come to a steep grade by watching the grade sighns like a 6or8 percent I put the Allison in first gear exhaust brake on FOOT OFF THE BRAKE And when the rpms build up to where it shifts into Secound gear I STAB THE BRAKE to get in first gear again by slowing down where the Allison shifts it self into first gear! I learned on the railroad with 14000 ton coal n soda ash Trains going down steep grades is that you do not let it GET OUT OF CONTROL!

maddogrdhg · 09-24-2020, 04:56 PM

They have given you great advice. I let the trans do its thing by pegging the throttle on uphill but occasionally the trans won’t find the right gear and then I shift till I hit about 2000 rpm and let it grind. On steep, long passes I sometimes get down to about 40mph.

On the downhill I try to crest it at 40max. Set the exh brake and many times it will hold it 45 or so but sometimes I have to also get on the brakes pretty hard to bring speed 40 or below.... repeat occasionally to maintain speed. Don’t ride the brakes even lightly. Go slow and you’ll be fine. Good Luck. Mike

Marc H · 09-24-2020, 05:04 PM

Uphill is fine, downhill can go sideways quickly. We like to start long grades going as slow as permissible, often 45 MPH. At 50K+ pounds the brakes can get really hot. With a slow start you can often manage speed with the jake, using chassis brakes sparingly.

mlpeloquin · 09-24-2020, 05:53 PM

I always use the Jake full time. It save the breaks. If going slower than the posted speed limit, use your flashers so that anyone coming up behind you is warned a head of time. Do keep it at or around 1800 RPM. That is even if you are slowed down to 30mph or slower. With your setup, you should never get that slow ever. A good reference is to go down hill at the same speed as up hill. The grade is usually the same. Not always, but with time you will be a better judge. Do not get complacent. Always error on the side of caution and safety.

rarebear.nm · 09-24-2020, 06:15 PM

Like others have said, using the same gear or speed downhill as uphill is just plain wrong. At least in the west the up and down grades are frequently very different in both steepness and curves. Drive the road that is in front of you not what is behind you.

Slow on the downhill is your friend.

J Birder · 09-24-2020, 06:37 PM

Quote:

Originally Posted by BobRay

Things have been pretty well covered here. I just wanted to emphasize a few points.

3. The old adage about using the same gear coming down that you used going up is nonsense. One side of the mountain may be *much* steeper than the other.

It's about time that somebody pointed this out. It always amazes me that advice that is so obviously wrong, thas so many people keep repeating it.

Actually, there's also another thing wrong with wrong with that advice. First, we probable went up, letting our transmission shift for us. If so, it probable shifted up and down several times, so we have no idea what gear(s) we were in.

Finally, even if I did, at the time, know what gear I was in, by the time I have spent two weeks camping on the plateau up on top, I have very little recollection of the details of driving up.

Joel