Which Transmission

[Lin]

I have run into some problems.  We have discovered cracks around the engine carriage.  My mechanic was going to weld them but showed me that the cracks have been welded before and broke because there were no plates.  Since the cracks seen to run on the inside of the rails and are not properly accessible he says he could not do the job right (could only do the crappy job as was done before and failed).  He says that maybe with a rack or even a pit, he might be able to do it.  However, he said the best way to do it is to remove the whole carriage and repair these and all other problems we find since we guess there must be more that we do not see.  Since I have been contemplating changing the transmission anyway, we agreed that this would be a good time to do it.  Now the question.  I have thought to change to an Allison 640 series.  This would involve me finding the transmission and all of the additional parts necessary.  Coincidentally though, a trucker I know just happened to ask me if I wanted a rebuilt Road Ranger Super 10.  He bought it for one of his trucks and then decided that he would be better off with an 18 speed.  He offered it to me for $3000., it's here and it should be a basic bolt in job.  This would be an easy way to go and I like easy.  The issue is whether I should go with an automatic.  Aside from my longtime preference for automatics, it would also be more convenient if I wanted/needed someone else to drive.  I am told that the Road Ranger is much better to drive than the Spicer which I do just fine on now.  So I am asking others with more comparative transmission experience for input.  Will driving a Road Ranger Super 10 be so good that one is likely prefer it to an Allison.  I know that the Spicer has not done that for me.  Yes, this may be a ridiculously subjective question, but all observations are welcome.

[TomC]

The nice thing about the Super 10 is that you can drive it like a straight 5 speed and just use the splitter when you want to.  If you don't know the Super 10 is shifted- 1L-1H-2L-2H-3L-3H-4L-4H-5L-5H.  As compared to the straight 10 spd that is shifted 1L-2L-3L-4L-5L (pull up the range shifter and start over) 1H-2H-3H-4H-5H.  The Super 10 is not made anymore, course the Allison MT640 series isn't either.  The Super 10 has always had a love hate relations with the truckers-either you loved the transmission or you hated it.  Granted you might get a bit better hill climbing with the 10 spd and 1 or 2 better mpg, but I can tell you that I really love my Allison automatic (and this after 21 years of over the road driving nothing but 13 speeds to the tune of 1.3 million miles).  Personally, for an RV there is no other choice than an automatic, with my preference being the Allison.  Now if you wanted a 10 spd autoshift, or Ultrashift (no clutch pedal) that would be the best of both worlds-automatic while retaining both the gear selection and fuel mileage.  But-the best acceleration goes to the Allison, no debate on that.  Good Luck, TomC

[Barn Owl]

What happens if you spend all that money and then wish you went for the auto? I agree with Tom, I like not shifting, and I have experienced both; because I also have spent some time stirring the stick.  Yuck!

V730 and love it,

Laryn

[RJ]

Lin -

Seeing as you have an MC-5A, you're in the same situation as GM owners:  Limited options.

Why do I say that?

Space considerations, mainly.

Your coach's engine compartment was designed around the 8V71 mated to the Spicer 4-spd thru a very short driveshaft into the dropbox.  There's not a lot of room in there for optional powertrain configurations, not only length, but width, too.  And making the driveshaft any shorter could create some very weird angles for the u-joints to operate, possibly shortening their life.

In all the years I've been around buses (25+ professionally), there seems to be only three combinations that work in the 5-series MCIs:

• Stock OEM 8V71/4-speed
• 8V71 mated to the MT-644 Allison
• 6V92TA mated to an HT-740 Allison

The 8V71 mated to an HT-740 will NOT work, it's too long.

Personally, I'd side with the Allisons vs the Super 10.  Far fewer issues involved, and the 644 fits/works.  Plus, do you really want to shift seven times just to get to 35 mph??  BTDT2. . .

A complete 6V92TA/HT-740 take-out package, altho you'd have to upgrade the cooling system and modify the turbo plumbing, would be the hot-rodder's choice.

FWIW & HTH. . .

[donnreeves]

With the super 10 in a bus,you would drive it like a 5 speed with an overdrive .There would be no need to use all the gears. Just use 1-5L then flip the range selecter to go to 5H. The beauty of the roadranger is the effortless clutchless shifts. That said, give me an Allison any time.   Donn

[Stan]

Like Russ said, the critical thing on a MC-5 is space. I know that the 644 works well and I have been told by other owners that they had different versions of the 600 series that also work. You cannot use the deep reduction model frequently used on garbage trucks because an extra bump on the side of the case rubs on an airbag.

I have never seen the 10 speed you referred to but I can imagine a nightmare trying to mount a shift tower on top of the transmission and then hooking it up to the handle at the front.

[Sojourner]

Being the bus is heavier & bigger that trying to keep up from loosing to automobiles being filling rapidly behind your stop & go traffic lane. I was thankful for my MCI-8 is automatic to nearly (and I said nearly) keep up with the traffic. Compare to class 8 trucks in this mast of confusions of stop & go traffic...my automatic move away and gain ahead of them every time. Other word standard trans allow more filling in of cars then automatic.

Automatic transmission fuel mileage is improve via lockup torque converter that is like being standard trans once pass take off point.

I have only put in about 12000 miles from MI to San Diego to MI to Bangor ME to MI to Arcadia FL plus many MI miles.

"See the USA...in your Motor Home with your automatic trans."

FWIW

Sojourn for Christ, Jerry

[buswarrior]

For the money, time and fabrication involved, and not being completely committed to the manual transmission...

Choice is clear, go automatic.

And I like the Super 10.

happy coaching!
buswarrior

[Sojourner]

buswarrior...I fully agree your feeling of liking the Super 10. For trucks hauling heavy load in all condition...a automatic-manual trans is the way to go.
However if you mean a automatic-manual trans without clutch pedal...then I am with you. I know with computer equips clutch & trans..it can be done if it not already now available???

Correct me if you will.

But for motorhome to retired in and at 70 years of age don't want to mess with start & stop in bumper to bumper traffic with extra pedal.

Everyone to his/her choice as he/she is please.

My nature love gears but need to relax.

FWIW

Sojourn for Christ, Jerry

[TomC]

Let me further clarify one point-if you're thinking of going with an Autoshift (with clutch pedal) or Ultrashift (no clutch pedal) these transmissions ONLY work with electronic engines since the transmission computer has to be able to override the accelerator to either stop fuel or give the engine fuel.  Only the Autoshift will work with a mechanical engine and that is called the Autoselect.  Works almost the same way, except you're working the accelerator pedal between shifts. 
I am probably going to make an RV with garage out of my old KW cabover.  It has a 13 spd in it now, but will be switching to an Allison HT740.  Even though the Allison is a direct drive compared to the 13 spd single overdrive (older style) with 3.55 and 11R-24.5 I will have a cruise of 1838rpm at 65mph and a 2100rpm speed of 74.25mph-which will be good enough for me.  The mechanical MT643 is a very reliable mechanical Allison automatic.  Parts are still made for it and it gets my vote for change.  Course-the 6V-92TA with the nearly bullet proof HT740 would be the hot rod choice (Detroit put a 435hp at 1350lb/ft version of the 6V-92TA in Jay Leno's Flx bus).  Good Luck, TomC

[Sojourner]

Thanks Lin, buswarrior and TomC

Very well answered my question and to others: (be sure to read the last half of report)
http://bulktransporter.com/mag/transportation_eaton_moves_fuller/

Now you have me informed to start thinking toward this route. I know it has to have computer equips engine with this trans.
Already planning to change engine in future but this make purchasing more practical then changing rear ratio...it already 3.83 or 3.89.

Right now I don't know for sure what is the trans ratio is but will look up.

FWIW

Sojourn for Christ, Jerry

[buswarrior]

Ok, the confusion starts...

Thanks to those that market product, they don't want you to know the truth, and mix up the words.
Then there are the brand names....
Then there are the repeated misuse of names...

So, let's see what we can do to sort this out.

Let's call it 4 transmission families:

manual, automatic, 3 pedal automated, 2 pedal automated.

a manual transmission: back in antiquity, the driver changed the gears via lever and linkage and there was a clutch to aid in sorting that out. Driver had to precisely manipulate the engine speed to match it all up. European heavies, keep your synchros to yourselves...

an automatic transmission: the clutch is replaced with a hydraulic drive, and the gears change by way of hydraulic pressure, the driver mashes foot to floor, everything takes care of itself.

And decades pass without this natural order being upset...

Then the electron crowd can't leave it alone.

Automated manual transmissions come along, first the 3 pedal variety.

The first attempt....Eaton makes a transmission that shifts the top 2 gears by itself, the other 8 by the driver. Lots of trouble before it miles out with the original fleets. Many are retrofitted to regular manuals. If a busnut considers one of these, he truly is nuts... working examples are pretty rare out there.

Eaton "Top 2" is often mistakenly called a Super 10.  Super 10 is a manual tranny with 5 shifts and a split for each gear. Top2 has electronics for the top 2 gears, regular roadranger otherwise. Regular roadranger has 5 shifts and then a range shift and then 5 more shifts.

Next attempt,

Popularly, Eaton's Auto Select and Auto Shift: take one perfectly good manual transmission, and mount an electronically controlled gear shifter on top of it. Driver still has to precisely manipulate the engine speed, and still has to use the clutch to start it from stop, just doesn't have to row the shifter. By the time you teach someone this thing, you might as well have taught a regular manual transmission...

These are the first that we might commonly call a "three pedal" system.

From the vantage point of the present, these are not particularly desirable, it still needs a driver who knows enough to manipulate it correctly, and can still burn clutches. When the driver and the electronics don't agree, vehicle will be seen stuck trying to go up hills from a start, and making stalled turns.

Bus crowd tried them, and sent drivers out with NO TRAINING! Almost every one of those buses eventually had an Allison retrofitted. What a disaster!

Electron crowd goes back to drawing board, smarting from the outrage of fleet owners that they still can't put unskilled people in their vehicles...

Current generation, here comes Eaton Ultrashift, ZF ASTronic, Merritor's I shift.

These are popularly called "two pedal" automated manual transmissions.

Electron crowd gets it much closer to right this time. Driver mashes foot to floor, transmission takes care of the rest. No clutch pedal, no engine speed manipulation, no changing gears. Sounds suspiciously like the interface of automatic above.... Same as your car, you may fool with it, but within its parameters, you can't force it to do anything.

The first wave of the Ultrashift et al is crashing onto the used truck market as we speak. The big boys are either completely switched over, or on the verge now. Completely ended driver abuse/mistake type transmission costs in the repair shop. Training is faster. Lovely to drive, even more fun if someone shows you the tricks to maximum control, but that's no different than learning to drive a slushbox, is it?

For a busnut, retrofitting an Ultrashift and it's mated electronic engine, from a truck, would be a fine swap! Nothing but wires front to back to run, no linkages to worry about, pack it in there and go.

So, manual, automatic, 3 pedal automated, 2 pedal automated might be the generic terms we should use?

happy coaching!
buswarrior

[Sojourner]

Good work...buswarrior!

[Tenor]

Great post Buswarrior!  Even a newbie gets it!  I've never driven a rig and I did not even know of some of those options.

[HB of CJ]

The HORRIBLE thing about shifting a Super Ten is that if you are coming from a trucker's background with lots of experience driving standard Roadrangers, eventually you will become tired, distracted, mad or just inattentive and you will employ muscle memory (brain memory?) and WILL TRY to shift your Super Ten like you have all the time shifted your ordinary Road Ranger Ten Speed.  We are human.

AUUUUUGHHHH!  OUCH!!!   $$$$$$$$  However, having just said all this bad stuff that MAY happen, if you have no experience shifting a Ten speed Roadranger, then the Super Ten will work just dandy in your coach.  Personally, three grand for a super 10 sounds quite reasonable, especially if he throws in the stuff needed to make it work in your Bus Conversion.  I have a RTO-910 in my Crown and I am a happy camper.

If you decide to go the Roadranger route you may consider finding, overhauling and installing a more suitable Roadranger 10 speed model that will/may/would wake up your coach.  Again, my bus has the RTO-910, an older model now no longer considered desirable due to the super close gears and lack of truly heavy duty torque capacity to work with todays electronic diesel engines.  For a highway truck, no.

However, for a coach conversion, yes, yes, YES.  You will laugh at hills. Steep grades disappear.  High summits summit.  Want to keep your two-stroke Detroit at 2000 rpm?.....all the time?  He he he, no problemo.  Mount a RTO-910 and you will be very happy.  You can still find them for under $1000 in fairly good shape, under $500 as a rebuildable core and for about $2000 overhauled with a good warranty.

Or.....and I love a good plan, you can do what you said earlier and find and mount/changeover to a good 640 series Allsion with the appropriate model and torque convertor.  Direct high gear.  The RTO-910 has a 22% overdrive.  I LOVE my Roadranger, but if I could afford it, an Allision would make the Crown much more user friendly for friends/family that can't or won't double clutch.  Your choice.