Auto or Manual Trans

[drewts86]

New kid on the block though I've been lurking here for quite some time. Looking for my blank canvas from which to build up and one question has come up that I couldn't really find much of an answer on: whether to find a manual transmission or go with an auto. I've come across only a few buses that had MTs and was wondering what the Pros and Cons were versus ATs. If autos were the industry standard for buses why are there even MTs?

[Albatross]

Some of the older buses were made before Automatic trannies became commonplace. As ride comfort is of chief concern to the passengers, automatics tended to provide that.

That said, manual trannies are generally safer and easier to pull or move if they break down, and you also can frequently use a 'push-start' to start them up if you have a problem with batteries or the starter motor. Maintenance is also cheaper/easier than with automatics. They frequently get slightly better fuel economy than automatics. But get stuck in traffic somewhere, and you'll more than likely regret it.

Auto's are easier to drive, but are more expensive, more difficult to work on, and can be damaged rather easily if you have to get towed with the drive wheels on the ground.

[Hank's P-O-S]

Ill second Albatross.

I prefer to drive manual transmission for several reasons though.
One is that I get to choose when to shift and how to shift.
That leads to my second point, I drive by sound. I know what gear I am in, and can therefor tell how fast i am going by the sound of the engine.

My third reason is that I park 2 buses and a 3 ton Uhaul on reasonably swampy land, at the back of a forest across 1/3 mile of pasture that is at places very soft and wet and have to drive 10 miles before a paved road.....well you get the point.....
I can control wheel spin.
More automatics get stuck on the field than manuals, I have gotten the bus stuck several times and can I tell you that is not fun.

[drewts86]

So it pretty much sounds like all the same pros and cons of the MT/AT argument in cars.

[Robin97396]

Driver preference basically. Although I'll go along with the added control in slippery situations with a stick. Still, here I am driving an Allison 4 spd that gets stuck in my yard while I'm turning around if the ground is wet.

[cadillackid]

another thing to think of issome of the Bus Manuals are not syncro'd. which means either RPM matching or double clutching every shift...

the more modern Automatics.. (allison 2000s) do a really nice job and are rated pretty reliably... the AT545 is mainly just older technology... I played with it on my bus when I test drove it and dropping it down a gear or 2 and I seemed to have plenty of engine braking... (granted on a DT360 with less than 40k miles on it so compression is high).. the AT545 does shift a bit sluggish at times but there are many thousands of them still in server all over the place..

I ALWAYS suggest a good cooler and a trans-temp gauge on any automatic.. the BIGGEST single destroyer of automatics is Heat... once you get that fluid too hot it is useless.. and needs changed.. most people that get a transmission hot never bother to change the fluid till the regular maintenance interval..

a manual does give you positive connection to your gear box so there is no power-lost in a torque converter.. However it may require lots of up and down shifting in the hills to keep your engine running in its power-band.. where a Torque converter properly mated to the engine will always try to keep the engine in its power-band through the "stall speed" rating of the converter...

-Christopher

[Hank's P-O-S]

Originally Posted by cadillackid

another thing to think of issome of the Bus Manuals are not syncro'd. which means either RPM matching or double clutching every shift...

-Christopher

nope, most are. The most common manual is the 5 speed spice (variants) of course, and as long as you aren't buying a bus from the 1970's it will be syncroed.

Basically every Bus/ MDT manual transmission after the early 80's are synchronized.

[Robin97396]

Yeah, but they usually need the syncro replaced in third gear. Lots of buses need a bunge to hold the stick in place because the detent balls in the transmission cap are worn out.

[Hank's P-O-S]

I'm not sure Id go as far as usually but definitely sometimes, just like any machinery things wear.
I would rather have a crappy 3rd in a manual than a worn out automatic. Granted I have never driven any real high mileage MDT (<250000 kms) but this is the first I have even heard of needing a bungee to hold it in gear.

Edit: Sorry if I seem like I want to argue. I don't.

[Robin97396]

I had a bus that wouldn't stay in third by itself. It was fine while accelerating but as soon as you slacked off the gas it would drop right into neutral.

Honestly I'd rather have a stick, but in this forward control bus that would be difficult.

[cadillackid]

Originally Posted by Robin97396

I had a bus that wouldn't stay in third by itself. It was fine while accelerating but as soon as you slacked off the gas it would drop right into neutral.

Honestly I'd rather have a stick, but in this forward control bus that would be difficult.

was a stick in an RE bus just plain a loose mess when it came to shifting?

[Robin97396]

Never had an RE bus. That's a whole nother kettle of fish.

[Alan N]

Originally Posted by cadillackid

was a stick in an RE bus just plain a loose mess when it came to shifting?

Mine shifts nice. Not as tight as a conventional shifter but not bad.

[Robin97396]

Is that shift set up kind of like in a VW Beetle?

[porkchopsandwiches]

I would say if you aren't a trucker or used to driving big sh!t go with auto. I put a bid in on a front engined 7 speed bus, didn't win, and was glad after sitting in traffic in my bus and driving it in urban hilly areas like san francisco, where a manual would be a nightmare. The 6 speed allison on my bus isn't worn out and shifts great, and has a lockup torque converter, so the MPGs dont take much of a hit. You've got enough things to worry about when driving a bus, you don't need more, IMO.

[cowlitzcoach]

Crown, Gillig, Pacific, and IHC RE buses had single shaft shift linkages. As a consequence the shift throws were relatively short and very crisp. It also made it very easy to upgrade from a 5-speed to a Road Ranger multi-range transmission since they used the same sort of single shaft shift linkage.

The other OEM vendor supplied chassis used by all of the eastern built bus OEM's used two rods with bell cranks. To adjust and account for different wheelbase lengths the rods were connected with pins and clevises. Over time as the bell cranks got sloppy with use and as the pins wore the holes in the clevises out the shift throws became longer and longer and sloppier and sloppier. The gear shifts would have more wiggle in gear than the single shaft gear shifts had in neutral. I have driven a few that in order to get to reverse which was up and to the right your head would go below the dash board as you reached over to catch the gear.

When it comes to choosing between automatic and stick shift the choice has pretty much already been made for you. Starting in the '80's the standard spe'c became the automatic and you had to pay extra to get a stick shift. I have only seen two school buses with stick shifts that have been made since 1990.

That isn't to say there are not any school buses out there with stick shifts. What I am saying is they are very few and far between.

As a young man I thought it was cool to have to manually shift the gears and only whimps drove automatics. As I have gotten older and gimpy with aches and pains I have to say it is really nice to be able to use a touch pad to choose my gears and not have to worry about pushing in the clutch pedal and rowing my way through traffic.

[EastCoastCB]

Originally Posted by drewts86

So it pretty much sounds like all the same pros and cons of the MT/AT argument in cars.

IDK, i like my cars with a manual. But driving a school bus with an auto is way better, imo. The turbo stays spooled between gears. The mt643 in mine is a real joy.
I'm missing half my left quadricep, and having driven a school bus through HORRIBLE Atlanta traffic, I couldn't imagine having to constantly work the long heavy clutch of a manual in a bus. Would suck royally, imo.

[porkchopsandwiches]

Originally Posted by EastCoastCB

IDK, i like my cars with a manual. But driving a school bus with an auto is way better, imo. The turbo stays spooled between gears. The mt643 in mine is a real joy.
I'm missing half my left quadricep, and having driven a school bus through HORRIBLE Atlanta traffic, I couldn't imagine having to constantly work the long heavy clutch of a manual in a bus. Would suck royally, imo.

I have been stuck in the same Atlants traffic, sweating my balls off, and the last thing I wanted to do was shift gears in a bus, haha. We ended up pulling off and getting BBQ and playing with a remote control car until the traffic went away

[cadillackid]

Originally Posted by porkchopsandwiches

I have been stuck in the same Atlants traffic, sweating my balls off, and the last thing I wanted to do was shift gears in a bus, haha. We ended up pulling off and getting BBQ and playing with a remote control car until the traffic went away

I have that to look forward to when I drive my bus from st pete to ohio in a couple weeks.. unfortunately I must make that drive without Air conditioning since the Air conditioning for my bus is in pieces inside a bunch of cartons .. lol I may run through atlanta at night or very early in the morning before it gets hot..

I'll get a hotel in the burbs and take off really early.. though I think the south side of atlanta burbs are not the Nicest ones..

-Christopher

[EastCoastCB]

Originally Posted by cadillackid

I have that to look forward to when I drive my bus from st pete to ohio in a couple weeks.. unfortunately I must make that drive without Air conditioning since the Air conditioning for my bus is in pieces inside a bunch of cartons .. lol I may run through atlanta at night or very early in the morning before it gets hot..

I'll get a hotel in the burbs and take off really early.. though I think the south side of atlanta burbs are not the Nicest ones..

-Christopher

I stayed at the bus friendly roach motel in McDonnough Ga a bit south of Atl, it was $34 and wasn't too scary. Excellent exit thats easy to get on and off of.
Late at night/early morning is definitely the way to go.
I never appreciated FL roads till I got home with my bus from Ky.