Starting out on steep incline

richard5933 · May 19, 2018, 07:20:29 AM

There are a couple of places around our house where it is necessary to start out in the middle of a steep incline. One is an intersection about two miles from home, and the other is the road in front of our house. Due to the layout of our driveway and the no-shoulder situation, the only approach into our driveway is uphill. Approaching uphill puts me on the opposite side of the road where there is enough turning space to get in the drive. If I approach from the downhill approach I'm up against the edge of the road and can't make the turn. Our house sits literally at the edge of the road with only a wood fence separating it from the road. There are many reasons that modifying the driveway entrance is not possible at this time, so I've got to get the hang of turning in from the uphill lane.

Usually I'm lucky enough to be able to time the turn into our driveway so that I don't need to come to a complete stop and can just roll through. But, when I need to stop for traffic it is difficult to get moving again. Same thing if I have to stop at the intersection down the road and wait for traffic. That one is even steeper. Seems like either I need to let the clutch slip to get moving or let the engine lug. Neither of these seem like a great solution.

Any secrets to starting out in first on a steep incline with a 4-speed and wet clutch? I don't want to burn out the clutch, but I also don't think it's great for the engine to lug its way through the start.

Bus has only 42K miles. Clutch is properly adjusted and works fine.

Any suggestions?

buswarrior · May 19, 2018, 08:30:20 AM

If the engine doesn't stall, all is fine.

You are not "lugging" the engine under these low power conditions.

You are dead pedal on the throttle at clutch take-up?

Hold the coach with light brake, take up weight of coach with clutch, transition from brakes holding to clutch holding to move off. No gritted teeth, no mashing of pedals, a finesse move.

And why not swing it out on the downhill side? The whole road is there to use... no collision, no offence, if that's what it takes, go on over there, proudly...

Happy coaching.
Buswarrior

TomC · May 19, 2018, 08:32:36 AM

Switching to a V730 Allison will solve all starting problems.

chessie4905 · May 19, 2018, 08:46:29 AM

Not to sound smart but this is exactly why GM owners switch to automatics. The oil style clutch in your coach will tolerate more slippage than the older dry type, but they won't take continued abuse just like older ones. I would check with Luke to see if replacement parts are available and the likelyhood down the line. The 41 and 49 series appeared to have a little lower first gear than the 4104's, although it may be the additional torque of the 8v-71. I never checked the manuals to compare. If clutch parts are scarce, you may want think of going back to automatic from a donor coach or your previous one if purchaser is parting it out.
One of the main reasons I moved to the 4905 was the automatic.
Another possibility would be to change the rear ratio to the 4:27 from your 4:11. Little better starting out power with a little loss in top speed. Moving to 11:00 series tires alone or combined with axle ratio another option. If parts are going to be scarce, I can save my 4905 clutch parts when I dismantle it. Price would be very reasonable.

edvanland · May 19, 2018, 08:53:40 AM

use the emergency brake to hold it till you start getting power to the drivers

chessie4905 · May 19, 2018, 08:54:34 AM

My 4905 would start out fine on dead throttle. If you are lugging it too low at creep speed, it'll let you know by stalling.

richard5933 · May 19, 2018, 09:11:33 AM

Quote from: buswarrior on May 19, 2018, 08:30:20 AM
And why not swing it out on the downhill side? The whole road is there to use... no collision, no offence, if that's what it takes, go on over there, proudly...

About 50 yards uphill is the crest of the hill which rises steeply on the other side. No way someone coming over the hill would see me making that maneuver. At least when I'm stopped on the uphill side I can see oncoming traffic a bit and make a dash for it when it's clear.

Quote from: edvanland on May 19, 2018, 08:53:40 AM
use the emergency brake to hold it till you start getting power to the drivers

I don't have a handbrake. The e-brake requires me to apply brakes before it lets me release.

Quote from: TomC on May 19, 2018, 08:32:36 AM
Switching to a V730 Allison will solve all starting problems.

Believe me, I'd love to do this. The guy that bought my old bus has an extra V730 already rebuilt. Problem is that I haven't got the cash to do this and don't see that happening this year.

In the end, seems like I just need to perfect my take-off skills. Practice, practice, practice I guess.

pabusnut · May 19, 2018, 12:17:53 PM

I don't have this exact problem, but have had trouble getting into campsites with my 4905.
I don't think mine idles less than 5 mph in first, which is way too fast to maneuver in and out of campsites.
My technique is to "bump"(let clutch fully out and immediately back in) in first or reverse to move and maneuver, then drift and/or brake. Repeat as necessary.

Maybe RJ can chime in, but I think there is a grade % already known where you are not going to start at all on a hill. Then downhill is the only option. It would be nice to know this ahead of time.

Steve

Geoff · May 19, 2018, 12:49:49 PM

If it was my bus, I would install a steering column brake lever like trucks have for trailer brakes, and run an airi line to the rear brakes. That will hold the bus on the hill until you get your rpms up and clutch starting to engage.

lvmci · May 19, 2018, 03:42:17 PM

Hi Richard, I think you need one of those 3' convex mirrors for you dead spot while turning in, lvmci...

HB of CJ · May 19, 2018, 03:55:50 PM

The designing engineers could have engineered into the final design a much lower starting gear. They did not. Who knows why. The 4106 MAY have had room for a designated 5 speed tranny. A little bit late today for correction.

My long gone old 1974 Crown Supercoach had the famous, (infamous?) close ratio Fuller RTO910 10 Speed Roadranger. First gear was still 6.59 to one. Start-ability in first gear was way over 20%. You just slowly let out the clutch.

Not possible with the 4 speed 4106. What to do? Like already said, try to look and plan ahead when making very slow steep climbs. The idle torque of the 8V71N will only work so well. That Coach was not designed for such hard duty.

pd4501-771 · May 19, 2018, 04:13:01 PM

Answer: drive the bus more. you will get the hang of it. No need to reduce the character of the coach by going automatic. It's a cool old bus, it should have a manual trans. Just as GM intended! I have driven two Scenicruisers with autos. Boring.

chessie4905 · May 19, 2018, 05:12:07 PM

GM intended? They finally went to automatics in those last years just like the other makes.
School bus based vehicles had more and lower gears for starting out on steep grades out in the country and in and around inner cities and towns with many stops. The GM models were intra city vehicles and drivetrain was designed around those conditions. Very durable with lower complexity.

bigred · May 19, 2018, 05:18:22 PM

The deal is ,these things were geared for high way use !! The first group that I was ever involved with that owned a bus had a 1948 3751 .Some of the churches we went to had steep drive ways that were made for cars .Fastest way for us to tell if we had sang at a certain church before was to step out of the the bus and see if the smell of a burning clutch was stell hanging around from our previous trip.lol

Geoff · May 19, 2018, 05:34:18 PM

I can only guess that an automatic is boring if you are all pumped up to shift, but it is the chitz in stop and go traffic. I am always impressed with how the Allisons are geared to keep the 2-stroke Detroit in the right rpm range. No lugging by stick-shift drivers who are used to 4-strokes that only need low rpms.