On ads, some listings for RVs list a Allison 4060 on older models, then Allison 4000 on newer. Same with 3060 and 3000.
Is there any difference 4060/4000 and 3060/3000?
I think we use hem interchangeably now. The older units had the 60 or 66 to denote the retarder. Now Allison says R or retarder option. It is either a 3000 series or 4000 series.
Correct, there are basically the two series, 3000 and 4000. The newer ones are rated for higher HP and torque, but are quite similar transmissions-- same gear ratios, torque converter lock up, electronic control, etc.
Hi Bret, your reply on this generated a question I have kinda thought about on the back burner for quite a while, and in particular when explaining coaches to potential buyers as I tout FT advantages.
When we say this or that tranny, and probably engine, is the same as used in big trucks, is that true? I anyway tell someone, oh that will be good, they use them like that in large trucks (I think the M11 in particular is the smallest in the trucks hauling 80,000 lbs?)
I figure the 4000 tranny is exactly the same in a truck as the FT, but I wonder. Same with the M11 engine, are they exactly the same or tuned or built a bit differently for the motorhome and not the same power or ability as in a big truck?
Mike,
While an Allison 4000 is an Allison 4000, I have never seen an OTR truck with that transmission. Commercial bus, yes, but not in an 80,000 GVWR truck.
We have a couple of retired truckers here on the forum who may be able to shed additional light on this.
We were told by the Allison guy at the local truck service/parts place that the garbage trucks they service have the 4000-series in them (no idea if they have the optional retarder or not)
The Allison 4000 is a "series" of transmissions. A 4060 would be the 6-speed version (including two overdrive speeds). An "R" at the end would indicate the built-in retarder. I believe there is also a 4070 (7-speed) version. My understanding us that in the commercial bus applications the Allison 4000 series is known as the Allison B500 series.
Most OTR trucker use manual or semi automatic trans. Semi automatics use the clutch only for starting and stopping. All other shifting is by wire. In top gear the semi auto and manual trans are direct drive units with no torque converter or other parasitic power losses. The lower MPG of a full automatic matters when high mileages are racked up every year. Automatics are used when there is a lot of stop-go involved such as city buses or the lack of trained (or trainable) drivers makes an automatic worth the extra.
Keith
Thanks David and Keith....makes so much sense about the manual transmissions, shoulda thought about that, recall these guys at traffic lights doing lots of shifting on those big trucks.
mike