4000Mh or br500 Allison??

robertglines1 · December 04, 2009, 08:59:49 AM

I am looking at XLII one has a 4000MH Allison and others have the B500.After seeing BK's problems is there a reason to stay away from the B500? All I'm looking at are used with over 300'000 miles on them..What miles are expected out of these transmissions before change out..

belfert · December 04, 2009, 09:08:24 AM

They are basically the same transmission. One is for the motorhome industry and one is for the bus industry. Perhaps the tranny in the one has already been replaced with a MH4000 instead of a B500.

robertglines1 · December 04, 2009, 09:12:22 AM

That explains it one is a factory shell and the others are seated coaches.Prevost factory shell.

luvrbus · December 04, 2009, 09:22:17 AM

Robert, the MH 4000 is basicly a B400 made for the S&S people they are a lot cheaper than B500 made for buses and trucks,the 4000 didn't come with the Prevost some body replaced the B500.
You can buy the 4000 off the self new for 18 grand and the B500 new will cost you 27 grand.
I bet both have been replaced or rebuilt according to the people that work on both 300,000 miles is about the average life span for B500 and 200,000 miles for MH 4000 series. The 4060 is the best of the 4000 sreies and 4560 is same almost the same as B500
The BR models life is less because of the heat they produce.

good luck

belfert · December 04, 2009, 09:23:32 AM

The current XLII motorhome shells use the B500 according to the Prevost web site. It seems strange that Prevost would use different trannies that are basically the same thing in two different models of the XLII, but anything is possible I guess.

belfert · December 04, 2009, 09:35:59 AM

I just looked at Allison's website. The 4000MH can actually handle more HP and torque than the B500 and they both have the same gear ratios.

If there are difference it would interesting to talk to someone at Allison about what the differences are. My understanding has always been that the B500 is basically a 4000 series tranny, but I could be wrong.

luvrbus · December 04, 2009, 10:06:17 AM

Brian, the 4000 series come in dozens of different models like the 4070 with a C-6 package is a 7 speed.
I may be wrong but the 4000 MH has an internal retarder where the B500r has external retarder

robertglines1 · December 04, 2009, 12:05:57 PM

The one with the 4000Mh said it is a 6 speed world trans and is in a prevo conversion shell 2005...repo...inside trashed..dual slide

robertglines1 · December 04, 2009, 12:34:49 PM

Just found out more it has a 14 liter 515 hp engine. 60 series..is said to have less than 45000 miles total coach miles...I plan on asking a lot more ? before jumping in..

TomC · December 04, 2009, 01:29:16 PM

B300, MD3060 are the same medium sized World Transmission. B400, MD3066, 3000MH, 3000HS are the heavy duty version of the medium sized World Transmission. B500, HD4060, 4000HS, 4000MH are the large sized World transmission. About the only difference between the HD4060/4000 series and the B500 is that the B500 has a shallow oil pan for ground clearance-hence heating might be an issue, and especially watching the oil level over the standard or deep pans. Good Luck, TomC