B500 vs other Allisons

[6805eagleguy]

So I am looking at putting a new engine/tranny combination in my bus,  I am researching the different types of allison transmissions.  I was wondering why the B500 is the bus tranny.  Is it the 6 speed overdrive?  Or the type of torque convertor?   
I could put in a 4000 HS truck tranny in just the same at this point.  I just need to run some ideas through the faithful bus community!
The Allison 400 MH is designed for motorhomes, with unlimited GVW and up to 650 hp.  There are tons of allison trannys out there, I just need to narrow it down to the one I need.  From there I will decide whether to get a rebuild or just a takeout.


Hopefully it will mount behind a 12.7 liter 60 series, near 500 hp.

Thanks in advance!

[bevans6]

The brochure I have says the B400 is rated 300 - 330 hp and 925 - 1000 lb-ft of torque.  The B500 is rated 420 - 550 hp and 1300 - 1700 ft-lbs of torque, which is probably why it's recommended behind the S60.  I think the B400 would be a good match for your 8V-71.  I'm trying to attach the brochure...

[luvrbus]

Any World Transmission would be waste of money behind a 8v71they don't have the power and torque to utilize the overdrives plus you are limited on the rear gearing on a Eagle your best bet is the 754 CR 5 speed. If you go with the 12.7 then use a B500 or the MH 4000
 

[6805eagleguy]

I am mostly trying to see the difference between the B500 and a truck transmission.  The truck tranny I am looking at right now is a 4000 HS highway series.

So lets compare the B500 vs 4000HS

B500: 6 speeds: Overdrive ratio: .64 in 6th:

4000HS: 6 speeds:  Overdrive ratio: .64 in 6th: 

Looking at the Allison Brochure they are exactly the same gear ratios throughout the 6 speeds.

So how is the B500 Special?

Edit:  I the 4000 Mh is similar to the 4000HS?


4000HS  http://www.powerforce.com/pdfs/transmissions/ds_pf_4000.pdf
B500  http://www.powerforce.com/PDFs/Transmissions/DS_PF_HT754CR.pdf

[lvmci]

By using proprietary factory specifications, lean manufacturing procedures, genuine OEM parts, state-of-the-art test equipment, and proper final calibrations,

What is "lean manufacturing procedures"?...

[Astro]

It is a bullshit way of saying..."We're organized".  A few years ago, the manufacturing buzzword was "synergy".  Middle managers were always verbally trying to capture it when in the presence of an executive.

[bevans6]

Reading between the lines of the product descriptions, the truck transmission is heavier duty, higher input torque specification, designed for heavier normal loads (80K plus) while the bus transmission is designed (although rated higher) for loads up to around 55Klbs and has shift pattern programming specifically suited to passenger comfort.  Fun to read the documents and try to decipher the actual from the marketing...  Certainly they recommend the 4000 for everything including bus and motorhome, while the B500 is definitely bus oriented.  They all use the same torque converters, again per the documentation.  I wonder what the actual physical differences inside the box are - I can imagine similarities but different clutch material specifications and what-not, as well as programming differences.  Or are they totally different transmissions?

[luvrbus]

Same case the B's are programed to shift easier with softer clutches that is why they don't last as long as the 4000 HD all buses come with the option of a 4000 or B500 the B500 is a 3000 dollar option on buses like a MCI or Prevost.I will try and post a photo of the applacation manual that tells all even the wiring harness and ECM is different on the 2 

[TomC]

Anytime a hyper powered Diesel truck needs an automatic (like a 16V-92TTA) they always use the HT740. You can't find a more reliable transmission then the mechanically operated HT740 (direct drive 4th-no overdrive). The HT754CR has the same starting 1st gear and same direct 5th. 2nd, 3rd, 4th are closer ratios for better climbing the hills-of which I don't think is necessary for our application.
I took out my 13spd single overdrive manual transmission (RTO14613A) (.86 overdrive) and replaced it with an HT740 with soft shift. The difference is, on a truck transmission you get 1st converter, 2nd converter then 2nd lockup torque converter continuous to 4th gear. On the soft shift between 2nd and 3rd, 3rd and 4th, the torque converter comes out of lockup during the shift then relocks up after the shift to make it a softer gear change.
I looked into the World transmissions and would have been $15,000 more! Stay with the tried and true HT740 and change the rear end if you don't like the top speed. Good Luck, TomC

[luvrbus]

Anytime a hyper powered Diesel truck needs an automatic (like a 16V-92TTA) they always use the HT740. You can't find a more reliable transmission then the mechanically operated HT740 (direct drive 4th-no overdrive). The HT754CR has the same starting 1st gear and same direct 5th. 2nd, 3rd, 4th are closer ratios for better climbing the hills-of which I don't think is necessary for our application.
I took out my 13spd single overdrive manual transmission (RTO14613A) (.86 overdrive) and replaced it with an HT740 with soft shift. The difference is, on a truck transmission you get 1st converter, 2nd converter then 2nd lockup torque converter continuous to 4th gear. On the soft shift between 2nd and 3rd, 3rd and 4th, the torque converter comes out of lockup during the shift then relocks up after the shift to make it a softer gear change.
I looked into the World transmissions and would have been $15,000 more! Stay with the tried and true HT740 and change the rear end if you don't like the top speed. Good Luck, TomC
[/quote  He dosen't have a wide range of gearing on a Eagle with a dropbox 3:76 or a 3:38 is about all that is left out there now

[kinson]

How would the life expectancy of the HT740 compare to a B500 used in a transit coach with equal miles?  Would it be similar to the b500 and mh4000 comparison?  Most B500 equipped transit coaches I see have over 500k miles which makes me wonder about the transmission health.

[luvrbus]

500k the B500 is about to the end of it's life I have saw 1 that lasted 700k before though.If you can find a Allison PO2454EN application manual to down load it will clear up all your concerns about the different models of the World Transmissions I think the other for the 1 and 11 World is the PO2478EN manual,I know you can download from Allison but the fee is expensive,I have the hard copy   

[kinson]

Anyone know the typical life expectancy of the ht740?

[luvrbus]

Anyone know the typical life expectancy of the ht740?

The old 740's were good for 1 to 1-1/2 million miles with a little TLC

[kinson]

The old 740's were good for 1 to 1-1/2 million miles with a little TLC

Dayum!