I would really like an overdrive trans for our eagle.
With the B500 the .74 5th gear and .64 6th gear would really drop the rpm's.
Currently @ 1500 rpm we are running about 52 mph, in fifth that would put us about 69mph and sixth would put us @ about 81 mph.
I would eventually like the series 60 to go along with it but for now I am thinking just the trans.
1. I am concerned with the width as the old 4 speed seems close on the drivers side. I can't find width specs. Centerline to outside edge @ drivers side is the tight area.
2. Will the b500 bolt to the existing bellhousing?
3. I haven't found much info on the electric controls.
Any thoughts or advise?
Looks like I have a lot to research.
Bill
The B500 is typically hooked up with a 4.56:1 differential gear in coaches.
Is there a way to get your current engine to "talk" to the B500?
What engine do you have?
1500 RPM at 69 mph is pretty tall gearing for an older technology engine to pull in the wind.
happy coaching!
buswarrior
The best place for you find out about installing the b500 in a Eagle will be the Eagles board www.eaglesinternational.net (http://www.eaglesinternational.net) not a easy task without removing the dropbox and flipping the rear axle so you can use the right gear ratio for the B500 the 3:73 or 3:36 will not work it needs to be in the 4:30 to 4:56 to use both overdrives on a b500.Plus you need a electronic engine.
Eagle used the Allison 746 with the 60 series with a boggie axle and dropbox then they used the B500 with the 60 with a tag axle to get the right gearing.
There are a few out there that will reprogram the B500 to work with the higher gear but Allison won't do it.
good luck
My Dina has 4.10 gearing. My B500 has been limited to only 5 speeds as supposedly the B500 does not like to be below about 1,450 RPM or so so the 6th gear would rarely be usable.
The only advantage I could see to lower gearing would be to climb hills a little better. The second overdrive with 4.56 gearing would probably be about the same RPMs as first overdrive with 4.10 gearing.
Remember the other end, lower gearing improves first gear start-ability.
What are the rest of the B500 ratios?
4.1 diff and .74 gives 59.9 mph at 1500
4.56 diff and .64 gives 62.3 mph at 1500
as noted, pretty much the same.
speed calculator: http://www.cwis.net/~mallie/page12.html (http://www.cwis.net/~mallie/page12.html)
happy coaching!
buswarrior
Belfert, you will find the B500 was set up that way in most if not all of the 11L series 60 but not the 12.7 model has to do with the torque not the rpms
good luck
Quote from: luvrbus on September 13, 2009, 07:49:21 AM
Belfert, you will find the B500 was set up that way in most if not all of the 11L series 60 but not the 12.7 model has to do with the torque not the rpms
I've been told it was due to RPMs, but they could be wrong. I have talked to one of the engineers who designed the Dina several times.
I don't know if Dina enabled the 6th gear when they were forced to switch to the 12.7 in 1997 I believe.
Belfert, the Prevost that had the 11L were setup the same way and some of those had 4.30 gears
good luck
KGD- for the price of installing the B500 with modifying the frame, drive train, installing the electronics with shifter, etc, the difference in fuel mileage will be less then one mpg, more in the fractions. Personally, I don't think it is worth it. I drive at 58 which is 1850rpm. Yours is geared to be 1673rpn @ 58. You're not going to get much better then that. As mentioned, the B500 will not stay in 6th much below 1500rpm (it is a small gear and Allison doesn't want it subjected to lugging vibrations). If you were driving 100,000 miles a year, I'd say go for it. But what do we drive a year-I do about 5,000 miles a year. Keep what you have and enjoy driving it. Good Luck, TomC
BW how you doing, eh.
Getting my engine to talk would entail all kinds of stuff I probably don't want to do like hooking up a throttle position sensor, tach pulse, spedo pulse, & lord knows what other issues, but still workable if I get hard headed enough. Its a mechanical 8v71. Yea 1500 I figure that would be the lowest available rpm, and I agree you probably don't want any grade either, actually probably 1600 would be right. The ratios are 3.51 1.91 1.43 1-1 .74 .64.
Current set up 5th @.74 6th @.64
RPM top gear
1300 unusable rpm with current 2 stroke 70 MPH
1400 48 MPH 65 MPH 76 MPH
1500 52 70 81
1600 56 75 87
1800 63 83 97 mph
With my 8v71 I am looking at the sweet spot being in fifth gear and only running between 1600 and 1800 RPM and and giving me 75-85 MPH. In sixth gear on a good run I was also hoping for 1500 RPM and 81 MPH on those flat long runs with 75 MPH speed limits and most running 85 MPH.
At 4 stroke upgrade time This works out to running 75 MPH at 1400 RPM which I think is within reason.
With the torque converter multiplication, it has to be better than the spicer 4 speed I have now. I was just reminded of startability recently on a WRONG Turn in PA, I hope to not repeat that situation again.
Thanks LB I will have to check them out. Yea I dont think its gonna be a cake walk, but I am going to have to do something sometime.
Belfert Yea I dont think with that double overdrive I would want to lug a 4 stroke below 1450 no less about 1600 on the 2 stroke.
TomC I agree, for the fuel mileage Its not worth it and I am not looking forward to it. I am like Sammy Hagar @ 55. I did the "math" The first time we headed to Jacks Bash in FL. & found hours of foot on the floor, 62 MPH being passed by grandma flipping me off cause I was holding up traffic. I cranked up the gov as a "quick" fix. That was 5-6 years ago and I really have enjoyed the ride, 5000 a year sounds about right.
We went to visit my Dad @ http://www.streamsidecg.com/ (http://www.streamsidecg.com/) in upstate NY and the speedometer started jumping for some time then quit altogether. To make a long story short, I burned the output bearing up on the trans. Our trip took a week longer than expected. I was lucky to find it when I did, and we didn't need a tow and I drove the bus home. The bad part was The bruises on my back from the gravel parking lot and the ever nagging thought the trans has other bearings that will go out and leave us in a predicament like this again.
At the time my options were pressed. I found several take out transmissions I could get shipped in. I never found a close shop that would change it and I couldnt do it in the parking lot. Bernhard bus in PA would put in a rebuilt 740 for $14-$15 thousand. Not including tow.
I could tow it home & deal with it there. I decided to have another look, not enough info. Well after hours -- days of chasing, tools, parts and some foul language, I found The cage on the bearing was gone. Well it wasn't gone, I pulled it out thru the drain hole. It had been completely chewed into small bits but there were no other bearing parts or parts of gears in my flush. I decided to pull the bearing, check the feel of the other bearings and go from there. After of a couple of days of the aformentioned foul language, a friend with a torch and a hand, tools, and overnight air freight for the bearing, we left for home, about 400 miles.
After the 4th flush I havent found any more trash, but I am going to put in something different before to long. She still shifts good, no odd noises, I pushed it up shift down shift hot, cold, 1 tough transmission. I am not looking forward to the whole intercooler install and the whole engine electronics yet as I Like my 8v71, and my$$$$$$. No less the down time of the bus. " Personally, I don't think it is worth it." I agree but peace of mind is priceless.
Thanks for the input. I am still trying to decide what and when. I am going to do the west coast trip this january and the clock is ticking.
Bill
One of the best places to look for a good 4 stroke engine with Allison auto is old trash trucks. The commonly used Cummins M11/ISM with Allison 4000 series transmissions. If you could find a crashed one and just buy the whole truck, the switch would be much less painful. Just a suggestion. Good Luck, TomC
There you go HGD some expert advice buying a engine and transmission from a trash truck they are just that trash very little maintenance done, high hours plus mileage and the PTO hyd system has beat the Allision to death and with screwed up gear ratios.
FWIW I know a guy that followed TomC's advice on that setup cost him a bunch.
good luck