Author Topic: Do any buses use Allison MT 644 transmissions ?  (Read 7660 times)

Offline 3408cat

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Do any buses use Allison MT 644 transmissions ?
« on: April 27, 2011, 05:43:14 PM »
Does anyone know if the Allison model Mt 644 was in any buses ? If so, were they any good ? Thanks, Bill.

Offline robertglines1

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Re: Do any buses use Allison MT 644 transmissions ?
« Reply #1 on: April 27, 2011, 06:18:06 PM »
Best I understand that trans was designed for the lighter weight Motor home industry.   Bob: PS  I stand corrected  It appears to be limited only by torque.  I WAS REALLY WRONG ON THAT ONE  Bad Me
« Last Edit: April 28, 2011, 05:40:53 AM by robertglines1 »
Bob@Judy  98 XLE prevost with 3 slides --Home done---last one! SW INdiana

Offline kwidd

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Re: Do any buses use Allison MT 644 transmissions ?
« Reply #2 on: April 27, 2011, 06:33:14 PM »
I have a bus in my yard with one in it. It is an mc5c old saudi bus. I run a mt654 in my prevost with a cummins m11. It's been in there for 5 years and about 40k miles. still working good. kent

Offline belfert

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Re: Do any buses use Allison MT 644 transmissions ?
« Reply #3 on: April 27, 2011, 07:54:10 PM »
Isn't the 644 more of a school bus transmission?
Brian Elfert - 1995 Dina Viaggio 1000 Series 60/B500 - 75% done but usable - Minneapolis, MN

Offline Lin

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Re: Do any buses use Allison MT 644 transmissions ?
« Reply #4 on: April 27, 2011, 08:00:51 PM »
The 644 and later the 647 are the heavier duty transmissions in the Allison 600 series.  Aside from whatever small internal differences there may be from the others, they have the same torque converter as a 740.  I have a 647 in my 5a.  I don't remember the exact specs, but I think it is rated for 305 hp and around 900 ft/lbs of torque.  I think it would be questionable to use in a 40 footer, but many have used them without issue in 35's.
You don't have to believe everything you think.

Offline Ed Hackenbruch

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Re: Do any buses use Allison MT 644 transmissions ?
« Reply #5 on: April 27, 2011, 09:09:32 PM »
The PO put one in my 5A and it now has 144,928 miles on it.  ;D
1968 MCI 5A with 8V71 and Allison MT644 transmission.  Western USA

Offline Dave5Cs

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Re: Do any buses use Allison MT 644 transmissions ?
« Reply #6 on: April 27, 2011, 09:12:02 PM »
I've got a 5C Saudi with the MT654  in it with the 6V- 71

Dave
"PATHFINDER"(Bus)
Toed 1998 Jeep TJ

Offline Ed Hackenbruch

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Re: Do any buses use Allison MT 644 transmissions ?
« Reply #7 on: April 27, 2011, 09:43:33 PM »
The MT644 is rated for 300 hp max, 780 lb.ft. of net input torque max, and vehicle weight (GVW) of up to 50,000 lbs.  Length is 30.42 in.  width  is 19.25 in. height is 21.60 in. and the dry weight is 565 lbs.  This is info from the sheet i have on my tranny. :)
1968 MCI 5A with 8V71 and Allison MT644 transmission.  Western USA

Offline bcaddel

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Re: Do any buses use Allison MT 644 transmissions ?
« Reply #8 on: April 27, 2011, 09:59:11 PM »
We have a 1971 MC7, 8V71 with the Allison MT-654. It is the only transmission I have any experience with in the bus, but I think it is great. We have put close to 30,000 miles on it and just today drove it almost 500 miles from Reno to Vegas pulling my wife’s Jeep with a jet ski trailer attached to the jeep. We sailed along at 60 plus mph with no issues.
Living in Nevada, we drive in mountains quite often and always pulling a toad. I do not have a temperature gauge for the transmission but is sounds and feels good to me (for whatever that is worth).
Hope this helps, I know you asked about the MT-644, but I assume they are similar.
Bob Caddel
Bob Caddel, Las Vegas Nevada
1971 MC7, 8V71, Allison MT654

Offline bcaddel

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Re: Do any buses use Allison MT 644 transmissions ?
« Reply #9 on: April 27, 2011, 10:14:49 PM »
C0zy pulling Triples.MOV

Cat
Here is a link to the video of the MT 654 in action
Bob
Bob Caddel, Las Vegas Nevada
1971 MC7, 8V71, Allison MT654

Offline Gary '79 5C

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Re: Do any buses use Allison MT 644 transmissions ?
« Reply #10 on: April 28, 2011, 01:12:28 AM »
5c & I have put 30K on my bus since acquisition, never a problem.

I might be incorrect, but I believe this trans is a bit shorter than the 7 series, and was a good fit in the 5 series, sans tag axle.
Experience is something you get Just after you needed it....
Ocean City, NJ

Offline Ericbsc

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Re: Do any buses use Allison MT 644 transmissions ?
« Reply #11 on: April 28, 2011, 05:36:12 AM »
I just pulled an mt-654 out of my eagle.(P.S. ITS FOR SALE) Bus had an 8-71n, and weighs app. 39k. I put almost 9k miles on it with no problems. It is not as big as the 700 series, but seemed to pul fine. I wouldn't use it behind anything over 300-325 hp if it were me.

Offline kwidd

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Re: Do any buses use Allison MT 644 transmissions ?
« Reply #12 on: April 28, 2011, 08:11:42 AM »
The engine in my bus is set @ 400hp and 1450 tq. The bus weighs just over 30k. I know we gone over 40k miles with this trans. I have been towing the last couple of trips so the gross was about 35k. I do run the same cooler as on a 700 trans. Kent

Offline 3408cat

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Re: Do any buses use Allison MT 644 transmissions ?
« Reply #13 on: April 28, 2011, 11:18:02 AM »
Thank you very much for all the information !  Bill.