Bus Conversion Magazine Bulletin Board
December 15, 2017, 04:29:28 AM *
Welcome, Guest. Please login or register.

Login with username, password and session length
News: If you had an Online Subscription: By clicking on any ad, a hotlink takes you directly to the advertiserís website.
   Home   Help Forum Rules Search Calendar Login Register BCM Home Page Contact BCM  
Pages: 1 2 3 [All]   Go Down
  Print  
Author Topic: 13 speed  (Read 1584 times)
harpold700 3
Jr. Member
**
Offline Offline

Posts: 53


72 mc7 8-71 stick




Ignore
« on: November 20, 2017, 04:24:54 PM »

any one retro fit a 13 speed into an mc7. transmission swap is simple, what about the shifter modification? Had read somewhere of a modification to the shifter, although it may have to be backwards. Not a real problem for the benefit of the 13 speed.  Any info will be greatly appreciated. thanks.
Logged
B_K
Hero Member
*****
Offline Offline

Posts: 1069




Ignore
« Reply #1 on: November 20, 2017, 05:00:24 PM »

I don't know any details but I do know it's been done before more than once.
Grin  BK  Grin
Logged
HB of CJ
Hero Member
*****
Offline Offline

Posts: 1724




Ignore
« Reply #2 on: November 20, 2017, 07:06:37 PM »

An overdrive 9 speed would also probably work, (power to weight ratio) and would be about 3.5 inches shorter?  May or may not make any difference with the drive shaft length.  Also that over drive would be slightly taller at about .73 or so?

My old Crown Supercoach had the RTO910.  One shift rod. Many grease zerts on the pillow bearings and a couple of U-joints.  Either the 13 or 9 would give you a high reverse necessary for those high speed reverse "boot legger 180's".
Logged
chessie4905
Hero Member
*****
Offline Offline

Posts: 1968





Ignore
« Reply #3 on: November 21, 2017, 04:24:21 AM »

They also make a remote manual shifter for these. A master unit at driver's area and a slave unit at tranny. Connects with two Morse cables. Fits all Roadrangers. Also if you use an RTO 9509 with the overdrive 13 speed rear section, you get a double overdrive with .63, .74, and .80. top three ratios.
Logged

GMC h8h 649#028 (4905)
Pennsylvania-central
luvrbus
Hero Member
*****
Offline Offline

Posts: 18575




Ignore
« Reply #4 on: November 21, 2017, 06:15:12 AM »

You will need to convert the clutch and flywheel over to make it work on a MCI the Roadranger transmission used a pull type double disk clutch they don't work right with the push type Long clutch MCI used.A simple shiftier is find a old White 7000 cab over with the air shiftier then you have no linkage 
« Last Edit: November 21, 2017, 06:20:01 AM by luvrbus » Logged

Life is short drink the good wine first
HB of CJ
Hero Member
*****
Offline Offline

Posts: 1724




Ignore
« Reply #5 on: November 21, 2017, 07:48:35 AM »

Do air shifters default to neutral if you lose air pressure?  Or ... do you stay in the gear you were in?  I dunno.  A mechanical linkage like already said, (cable or shift rod) still lets you use your Jake. 

Which can bring you to a complete stop.

Nothing wrong with the single shift rod with pillow bearings and U-joints.  The Crown Supercoach has the pancake engine in the middle.  When greased up the shifting is very smooth, quick and easy.

More like shifting a dirt bike than a big 10 speed.  About one inch of shifter movement.  About 3-5 pounds of effort needed.  Very easy to "lay" against a gear and feel where you are.  Kid easy to use.
Logged
luvrbus
Hero Member
*****
Offline Offline

Posts: 18575




Ignore
« Reply #6 on: November 21, 2017, 07:53:45 AM »

Yep the ones I been around would default to neutral only draw back was if you accidentally grasped one entering the cab they would shift into gear   
Logged

Life is short drink the good wine first
TomC
Hero Member
*****
Offline Offline

Posts: 8471





Ignore
« Reply #7 on: November 21, 2017, 08:00:28 AM »

Most recent cabover trucks used a cable shifter (my '85 Kenworth did). Then all you need is mount the shifter in the front and have long control cables made back to the transmission. You can hook them up so it does shift the normal way-commonly called the X and Y shifter.
I had a 13spd single overdrive in my truck (RTO-14613A) for nearly 1.2 million miles of commercial driving. The transmission was rebuilt at 330,000 miles, and the clutch was never replaced when I switched to the Allison HT740. I just wished I had the Allison HT740 when I was driving. Personally-the only transmission swap I would do is to change it to an Allison automatic. Changing from the 4spd to a 9 or 13spd is a big job. Yes you'll get better low gears, but ultimately going up a hill is determined by the torque output of your engine. Yes you might get 2-5 mph better going up a hill because of more gear selection, but driveability wise, there's nothing that can replace the Allison. Good Luck, TomC
Logged

Tom & Donna Christman. '77 AMGeneral 10240B; 8V-71TATAIC V730.
luvrbus
Hero Member
*****
Offline Offline

Posts: 18575




Ignore
« Reply #8 on: November 21, 2017, 08:06:00 AM »

Yep Allison is the way to go and so easy on the drive train too 
« Last Edit: November 21, 2017, 08:10:27 AM by luvrbus » Logged

Life is short drink the good wine first
harpold700 3
Jr. Member
**
Offline Offline

Posts: 53


72 mc7 8-71 stick




Ignore
« Reply #9 on: November 21, 2017, 01:38:59 PM »

Allison would require a cooler. Could I use a remote cooler?, read don't need, cant take any more heat to the cooling system.
Logged
RJ
Angola Coach Conversion "Aesop's Tortoise"
Hero Member
*****
Offline Offline

Posts: 3533





Ignore
« Reply #10 on: November 21, 2017, 05:02:26 PM »

Allison would require a cooler. Could I use a remote cooler?

Yes, you can use a remote cooler, it just has to have the capacity to handle the heat load.

Since you've got an MC-7, you can easily mount one on your louvered side access doors. 

CAVEAT:

The engine cooling blowers pump a LOT of air into the engine compartment.  You'll need a really strong fan system on the remote cooler to overcome the engine blowers.

FWIW & HTH. . .

 Wink
Logged

RJ Long
PD4106-2784 No More
S13406 1978 MC-5C Converted
6V71/MT-644
S14947 1980 MC-5C Shell
6V92/HT-740
Cheney WA
lostagain
Hero Member
*****
Offline Offline

Posts: 2380


MC5C




Ignore
« Reply #11 on: November 21, 2017, 05:28:47 PM »

RJ and harpold, have the fan in the side engine door blowing from inside to outside so it goes with the flow, instead of fighting the squirrel cage fans.

JC
Logged

JC
Blackie AB
1977 MC5C, 6V92/HT740
chessie4905
Hero Member
*****
Offline Offline

Posts: 1968





Ignore
« Reply #12 on: November 22, 2017, 04:13:45 AM »

Just clean fins periodically as grease and, oil, and dirt is going to collect on it. You can use an aftermarket automotive radiator cooling fan.
Logged

GMC h8h 649#028 (4905)
Pennsylvania-central
bevans6
Hero Member
*****
Online Online

Posts: 5905


1980 MCI MC-5C




Ignore
« Reply #13 on: November 22, 2017, 06:31:46 AM »

RJ and harpold, have the fan in the side engine door blowing from inside to outside so it goes with the flow, instead of fighting the squirrel cage fans.

JC

Can work but difficult.  The rear side of the bus is a quite high pressure area at speed, the inside of the engine bay is a low pressure area.  Fans blowing air from a low pressure area to a high pressure area have to work pretty hard.  If the cooler was at the rear doors, the back of the bus is a low pressure area and that could work pretty well.  You need a fairly sizable cooler.  The one I used (MT647) had a core that was 22" by 25", three inches thick, and overall height of close to 30".  Around 125,000 btu.  I mounted it fairly vertically beside the engine, standing upright on the old AC compressor mounting frame.
Logged

1980 MCI MC-5C, 8V-71T from a M-110 self propelled howitzer
Spicer 8844 4 speed Zen meditation device
Tatamagouche, Nova Scotia
harpold700 3
Jr. Member
**
Offline Offline

Posts: 53


72 mc7 8-71 stick




Ignore
« Reply #14 on: November 22, 2017, 04:46:39 PM »

How about a six speed , will my shifter gate move for 2 more holes? Or do I need a new shifter?
Logged
harpold700 3
Jr. Member
**
Offline Offline

Posts: 53


72 mc7 8-71 stick




Ignore
« Reply #15 on: November 23, 2017, 04:14:38 PM »

Heck with all this transmission swap, I'll just turbo it, thanks for all the input.
Logged
buswarrior
Hero Member
*****
Offline Offline

Posts: 4220


'75 MC8 8V71 HT740




Ignore
« Reply #16 on: November 23, 2017, 05:28:33 PM »

Now your talking... !

Turbo motors also make lots of heat...

No free lunch?

The cooler for an auto isn't a big deal, mount in the side door, and put a proper fan, job is done.

I like a 13 speed too...

Happy coaching!
Buswarrior
Logged

Frozen North, Greater Toronto Area
TomC
Hero Member
*****
Offline Offline

Posts: 8471





Ignore
« Reply #17 on: November 23, 2017, 06:07:39 PM »

If you have a 4spd manual, your shifter works with two rods-one rod for 1st and 2nd, the second rod for 3rd and 4th. Both rods only move fore and aft-no side movement. That's why reverse is taken care of by electric solenoid shifting to 2nd.
Any other transmission you want to put in you need an X and Y shifter-meaning one rod or cable that goes fore and aft and the other goes side to side. Gillig and Crown and many other rear engine buses with multiple spd transmissions typically used a single long shifting rod that goes fore and aft and rotates for side to side-built much like a driveshaft with U-joints in them for going up and down with the floor. Or for conversion can use a shifter from a cabover that uses two Morse type cables for the fore and aft, and side to side.
Still complicated to switch-better to just drop in an Allison automatic. Good Luck, TomC
Logged

Tom & Donna Christman. '77 AMGeneral 10240B; 8V-71TATAIC V730.
luvrbus
Hero Member
*****
Offline Offline

Posts: 18575




Ignore
« Reply #18 on: November 24, 2017, 06:24:16 AM »

It hasn't been covered but a good thing about a Allison is the torque converter will let the engine build up the torque faster and easier
Logged

Life is short drink the good wine first
Geoff
Hero Member
*****
Offline Offline

Posts: 1217





Ignore
« Reply #19 on: November 24, 2017, 07:02:12 AM »

I agree on the Allison.  Shifting a Roadranger and having to use a clutch in stop and go traffic gets old.  For transmission cooling, the stand alone cooler from a V730 works well and are easy to find.
Logged

Geoff
'82 RTS AZ
bobofthenorth
Hero Member
*****
Offline Offline

Posts: 2347



WWW

Ignore
« Reply #20 on: November 24, 2017, 07:58:55 AM »

I had a 10 speed RTU in the Prevost.  It was OK but no way would I swap transmissions and install a Roadranger.  If you're going to the bother and expense of a swap, do it right and get you an Allison.  The RR was great on the road but so's an Allison in lockup.  I had a few extra gears so - in theory - I could pick the right one for the situation easier than with an auto but that was the only advantage and its mostly a theoretical advantage.  The real problem with a RR is in town in stop and go.  You're always going back and forth from Hi to Lo range and the 13 isn't going to be any different than the 10 speed.  Somewhere around 20 MPH you're going to have to change ranges and go back across the shift pattern and then the brake lights ahead of you will come on and there you'll be, going back down into the basement and then traffic will start to move again and you're back up across the gate.  It gets old real quick.
Logged

R.J.(Bob) Evans
Used to be 1981 Prevost 8-92, 10 spd
Currently busless (and not looking)
My website
Our weblog
Simply growing older is not the same as living.
TomC
Hero Member
*****
Offline Offline

Posts: 8471





Ignore
« Reply #21 on: November 24, 2017, 08:31:44 AM »

When I was driving truck and was in town with my 13spd, I would always skip gears. I'd start in 2nd, shift to 4th, pull up the button then shift through the gears of 6th, 8th, 10th etc. Drive it more like a 6spd, then when on the highway kick it into overdrive with the air switch on the shift knob.
Driving a 10spd would be the same thing. Start in 2nd, shift to 4th, pull up the button, then continue with 6th, 7th, etc. There's nothing written that you have to go through all the gears all the time. Good Luck, TomC
Logged

Tom & Donna Christman. '77 AMGeneral 10240B; 8V-71TATAIC V730.
HB of CJ
Hero Member
*****
Offline Offline

Posts: 1724




Ignore
« Reply #22 on: November 24, 2017, 11:32:41 AM »

My old 1974 long gone, (I am now bus less! Sad) Crown Supercoach would easily pull down or high idle lug down to about 12 mph in 6th gear on flat ground.  Still in the high side.

Then quickly accelerated with just a little bit of right foot.  The cruising sweet spot seemed to be right at 1500 rpm which equaled 60 mph in 10th gear.  Fuller RTO910.

Like already said better, one did not have to use all the gears.  Normal starts were made in 2nd gear.  Tenth, (10th) gear was only good for about 60 mph or faster.

Sometimes that desired 60 mph could only be maintained in 9th gear.  Certainly not a hot rod.  Small Cam C U M M I N G S 250.  No turbo.  The gears were very close.

This made maintaining a certain road or traffic speed very easy, within the power capabilities of the Crown.  A gear for every situation and some gears you did not need.

The RTO910 was certainly a better more flexible tranny than the usual Fuller T905 5 speed.  Where it shined was tight twisty mountain road driving maintaining speed.

Where it DID NOT shine was in that aforementioned horrible stop and go driving below that critical low speed of about 12-15 mph.  Then you wandered between lo and hi.

But ... on the open road it was superior.  My opinion only.  At speed one did not have to shift at all.  But ... if the engine began to work and the road speed began to drop?

Very easy to drop one gear.  Then another gear.  Easy to keep the rpm up.  But ... nowadays BETTER transmissions exist?  Oh yeah.  How about a New World 6 speed?

Kinda like the neat HT740 but with two additional over drive gears?  Or ... 66 mph, 85 mph, then 100+ mph?  Plus no clutch pedal.  No double clutching.  No tired left leg.
Logged
bobofthenorth
Hero Member
*****
Offline Offline

Posts: 2347



WWW

Ignore
« Reply #23 on: November 24, 2017, 11:44:07 AM »

Everybody skip shifts a RR once they get used to it.  Unless you guys are claiming you could start in 6th you still have to go back and forth across the gate in town.  Your knee still gets sore over time.
Logged

R.J.(Bob) Evans
Used to be 1981 Prevost 8-92, 10 spd
Currently busless (and not looking)
My website
Our weblog
Simply growing older is not the same as living.
harpold700 3
Jr. Member
**
Offline Offline

Posts: 53


72 mc7 8-71 stick




Ignore
« Reply #24 on: November 24, 2017, 02:59:19 PM »

I have been driving for31 years, shifting is not scary . 13 speed would be killer behind 318, but at what labour to do it.  This stand alone V730 cooler you speak of interests me, I have access to an Ht747.  Am I heading down the right road ? Any advice or directions to said V730 coolers? thanks.
Logged
TomC
Hero Member
*****
Offline Offline

Posts: 8471





Ignore
« Reply #25 on: November 25, 2017, 08:42:21 AM »

Just look at Hayden web site. You need 1" fittings. They many coolers with and without built in fans for Allison transmissions. I have both the standard shell cooler that uses the coolant from the engine. I added an air to oil cooler with thermostatically controlled fan to take the initial heat load off. So the transmission fluid flows first through the air to oil cooler then flows through the coolant to oil shell cooler. I did this hoping to keep some transmission heat from the radiator.
The secondary advantage of the coolant to oil shell cooler is that it heats up the transmission faster and actually will keep the transmission from running to cold on a wintery day. Good Luck, TomC
Logged

Tom & Donna Christman. '77 AMGeneral 10240B; 8V-71TATAIC V730.
chessie4905
Hero Member
*****
Offline Offline

Posts: 1968





Ignore
« Reply #26 on: November 25, 2017, 09:04:33 AM »

I've never seen an automatic transmission not work right because of cold weather unless it has a problem. All the automatic trans I see now use a separate air cooled  unit.
Logged

GMC h8h 649#028 (4905)
Pennsylvania-central
luvrbus
Hero Member
*****
Offline Offline

Posts: 18575




Ignore
« Reply #27 on: November 25, 2017, 09:19:21 AM »

Most all the buses with the 4000 or B500 use a water to oil cooler the B500 needs to reject 340,000 btu of heat per hr minimum the old 700 series required 4000 btu per minute     
Logged

Life is short drink the good wine first
Geoff
Hero Member
*****
Offline Offline

Posts: 1217





Ignore
« Reply #28 on: November 25, 2017, 10:20:47 AM »

I have used a laser temperature gun on my V730  transmission and it runs 180f, same as the engine.
Logged

Geoff
'82 RTS AZ
harpold700 3
Jr. Member
**
Offline Offline

Posts: 53


72 mc7 8-71 stick




Ignore
« Reply #29 on: November 25, 2017, 06:31:38 PM »

Thanks, I'm on it.
Logged
buswarrior
Hero Member
*****
Offline Offline

Posts: 4220


'75 MC8 8V71 HT740




Ignore
« Reply #30 on: November 26, 2017, 08:59:54 AM »

Think REALLY hard about keeping the tranny heat OUT of the engine coolant.

The MC7 has the smallest radiators, as it was never intended to cool anything but the engine at it's design.
The last of the MC7 had auto available and were horrible over-heaters in stock configuration.

Hayden oil to air coolers is the way to go.

happy coaching!
buswarrior
Logged

Frozen North, Greater Toronto Area
harpold700 3
Jr. Member
**
Offline Offline

Posts: 53


72 mc7 8-71 stick




Ignore
« Reply #31 on: November 27, 2017, 03:38:51 PM »

Oh yes on keeping engine to it's self, there is no way I can introduce more heat to the substandard cooling system. . Trans cooler will have to be on it's own. I will have to get on to Haydens catalog.
Logged
Pages: 1 2 3 [All]   Go Up
  Print  
 
Jump to:  

Powered by MySQL Powered by PHP Powered by SMF 1.1.18 | SMF © 2013, Simple Machines Valid XHTML 1.0! Valid CSS!