Community Forums

Jaston47 · 12-20-2013, 11:19 AM

How to shift in hills, at what rpm do I shift going up hill . I have a phaeton 40 foot with 6 speed Allison

t55watson · 12-20-2013, 11:38 AM

You don't. It is called an automatic for a reason.
The 6 speeds are great for pulling hills.
I had a couple of 4 speeds and they needed help but the 6's work well on their own.

Jaston47 · 12-20-2013, 12:00 PM

Some times I get down to 35 on long hills do I need to down shift

t55watson · 12-20-2013, 12:10 PM

If the tranny has dropped to 4th gear you should be good for RPM. You could drop to 3rd to keep the revs up but stay aware of the need to up shift when the revs start to climb.
I will on occasion manual down shift to 4th if the tranny keeps cycling from 5 to 4 and back.

Steve Ownby · 12-20-2013, 12:15 PM

Quote:

Originally Posted by Jaston47

How to shift in hills, at what rpm do I shift going up hill . I have a phaeton 40 foot with 6 speed Allison

You can optimize your coaches performance on those long up grades if you do a little preemptive shifting. You need to be aware of your engines performance characteristics and where it generates it's max horse power. The thing that automatic can't do is look ahead and see the 5 mile 7% grade coming up. You need to downshift early and try to keep the rpms up close to that max hp figure. When it falls, as it will, shift again. While doing this, watch your engine heat, as it will start to rise. If you start generating more heat than your cooling system can handle, the cure is to down shift again to keep the rpms up and back out of the throttle.

A little practice in the mountains & you'll get the hang of it.

krivanj · 12-20-2013, 01:53 PM

My former Cummins ISC with a side radiator would increase temperature going up a long grade unless I manually downshifted. The owners manual for the Cummins said 212 was max temperature and I would start approaching that on strong grades. Others, a few years ago on this site, told me when going up a long grade to keep the rpm's to 2000 if the temperature rose too high. I started doing that and no longer had the problem.

Jaston47 · 12-25-2013, 04:50 PM

Quote:

Originally Posted by krivanj

My former Cummins ISC with a side radiator would increase temperature going up a long grade unless I manually downshifted. The owners manual for the Cummins said 212 was max temperature and I would start approaching that on strong grades. Others, a few years ago on this site, told me when going up a long grade to keep the rpm's to 2000 if the temperature rose too high. I started doing that and no longer had the problem.

thanks

Oregon Duck · 01-03-2014, 07:29 AM

Quote:

Originally Posted by Jaston47

How to shift in hills, at what rpm do I shift going up hill . I have a phaeton 40 foot with 6 speed Allison

I have a allegro bus and went to colorado this summer. Keeping the rpms to 2000 by downshifting on steep grades works very well. Check out your allison manual. This also helped keep my speed up. Interstate 70 has a lot of steep grades.

vfr750nm · 03-02-2014, 06:59 PM

So if I get this straight? Does everyone leave the Overdrive Switch on when driving? I tend to turn it off if heading up a steep incline to keep the RV from flooring it and dropping from 6th to 4th if I left it on. Suggestions? Thanks.

luvlabs · 03-03-2014, 06:30 AM

Quote:

Originally Posted by vfr750nm

So if I get this straight? Does everyone leave the Overdrive Switch on when driving? I tend to turn it off if heading up a steep incline to keep the RV from flooring it and dropping from 6th to 4th if I left it on. Suggestions? Thanks.

Generally in a gas coach you put it in tow/haul and let the transmission figure it out. If you only have a O/D switch, then dropping it out of O/D is fine to limit the amount of shifting going on.

djbmsu · 03-03-2014, 07:11 PM

Same with the Allison, turn off the "economy mode" switch for hills.

wa8yxm · 03-04-2014, 07:21 AM

With an Allison. it's very easy.

First: Turn on the GRADE BRAKE switch.

When the speed starts to pick up apply the service brakes (Foot brake) to bring it down, transmission will downshift.

If you need to slow more, it will downshift a 2nd time

I DO not know if it will downshift a 3rd time as I have a 5 speed.

If you let the speed climb to the point where the engine is in danger of over-rev damage, it will UPSHIFT

The allison is smarter than the average driver (IE: ME).