This is a demonstration of the power flow through an Allison 1000 six-speed automatic
transmission. this transmission is used in 2001 through current Chevrolet and GMC heavy-duty
trucks in particular with the Duramax 6.6 liter diesel the Isuzu Duramax the General
Motors uses this transmission has gone through four generations and possibly a fifth for 2011
of changes and 2001 was all by itself it was a five-speed transmission but yet all
the components of the main planetary gear sets were still there so it could have been
a 6-speed had they had programmed the TCM the transmission control module to have six
gears then there was a 2000 a change in 2002 some software changes to have some increased
pleasantness I guess decreased harsh ships particularly down ships but this had a hard
up shift hard downshift even an engine flare up during shifting because this Allison transmission
is a transmission that does what's called a clutch to clutch shift which means it shifts
just like a manual transmission meaning that in between each shift it goes to neutral so to go
from first to second we have first gear then we go to neutral then we go to second and they had
the timing not quite right on those we had a lot of customer complaints on this thing about the oil
pump being noisy at idle so in 2004 they added a solenoid G to the valve body which only was
used at idle and would turn down the line sir from maximum down to a lower pressure to where
the pump wasn't as noisy and then in 2006 they went to the fourth generation controls turned
it into a six-speed did not add any additional solenoids make it a six-speed or any additional
parts that's my understanding their software changes a computer change and possibly some valve
body and case changes corresponding to the sixth gear Edition and then in 2011 for the new Duramax
with the increased power for the 2010 Tier four emission standards that engine has closed that
Duramax engine has close to eight hundred pound feet of torque so they did some modifications to
strengthen the transmission for 2011 so what I'd like to start with is showing you the parts of the
Allison transmission what I have here is actually what's inside the torque converter this is called
the turbine and it's hooked to the input shaft here and so if the turbine turns then power can
flow into the transmission but there is no direct connection between the input shaft and the output
shaft unless we have some clutches apply this input shaft connects to the C1 clutch housing the
C2 clutch housing and the rotating clutch module on this piece right here is the rotating clutch
module this entire thing fits over the input shaft and splines to this piece here so these teeth
inside of here spline to this and the input or this rotating clutch module is also splined to the
input shaft so if the input shaft turns it also does this piece of metal here and this piece of
let's hope to the Sun gear of our first planetary gearset this thing has three planetary gear sets
they are quite easy to remember this one's called the P1 or planetary gear set number 1 P2 and P3
so three planetary gear sets there are also three clutch packs that connect to those planetary gear
sets as far as the ring gear is concerned we can see the ring gear on the outside of these three
planetary gear sets and clear in the back of the transmission back here we have the C5 clutch pack
which has six fiber plates and seven steel plates and it splines here the fiber plate splines to
this the ring gear the steel plate splines to the case and when that clutch applies it stops the P3
ring gear from rotating and then we have the p4 I'm sorry it stops yeah P3 then we have the
piece or the C4 clutch that stops the P2 ring gear from rotating so we have a C4 clutch turns out the
clutch disc is this are the same for the C4 clutch and a C3 clutch which stopped the P1 and the P2
ring gears and then they have the same metal plates that's blind to the case the difference
between the C3 clutch and the C4 clutch is the C3 clutch has four fiber discs and five steel discs
where the C4 clutch has five fiber discs and six steel plates and so these three ring gears here
with the C3 C4 and C5 clutches stopped when those clutches are applied and then the power coming in
from the input shaft connects to the C1 clutch this is a clutch disc and still played out of
the C1 clutch as you can see it's much smaller but it can be much smaller cuz we've got a first
gear ratio of 3.10:1 so it's 3.10 times easier to move the vehicle
in first gear so we can have a clutch disc that's 3.10 times smaller and still handle the
same torque and load and then it has I forget how many clutch disks it has it, I think it's six
it's a pretty good number of the C1 clutch disks and the C1 clutch is going to connect
the input shaft to this C1 clutch housing the C1 clutch housing connects to an intermediate
shaft that goes down the middle of these planetary sets and it connects to the two Sun gears that are
in the P2 and the P3 gear set and then we have an output shaft back here so there's three shafts on
this transmission we have the input shaft the intermediate shaft that's underneath all of
this and our output shaft then we have the C2 clutch and you can see it's a little bit larger
of than the C1 when it's not quite as large as the C3 they're close but the C2 is a little bit
larger the C2 clutch disks are going to spline to this out outer housing right here and it grabs the
planet carrier of the P2 planetary gearset and it has steel plates also but unlike
these three clutches that when they apply they stop these three pieces from rotating these two
clutches up here to C1 and the C2 clutch when they apply they connect power from the engine
through the turbine input shaft to the C1 clutch and the C2 clutch they connect power to our
planetary gear sets so we have power going to the intermediate shaft which drives the two Sun gears
in the middle here we have power going to the C2 clutch which drives the planet carrier of the
and then we have power going to this metal piece which strives the Sun gear of the P1 always so for
each set of planetary gear sets we can get two forward gears this is a six-speed transmission
it's also a five-speed if you're talking about the Allison 1000 prior to 2004 model year
so what I'd like to do is show you how the six forward gear ratios are obtained and how
reverse is obtained first thing for first gear we are going to have the C5 clutch apply which
is going to stop this P3 ring gear from rotating and then we're also going to apply the C1 clutch
which is this housing right here so we're going to have to see one clutch turning because
it'll be connected to through the turbine in the torque converter to the input shaft we're going
to have this the P1 Sun gear turning at the same time and we'll have the C5 clutch applied holding
this the P3 Sun gear and so this should give us 3.1 turms of the input to one turn of the
output and you can see over here that I've got these I've got the output shaft labeled let me
zoom in a little bit so you can see the labels a little bit better as we do this and so we'll
watch how how many times it takes to turn the the input to get one term of the output for first gear
it should be 3.1 so I'm going to grab the C1 clutch housing and this rotating clutch housing
and I'll hold the C5 clutch from turning and then we'll see if see if we get 3.1 turns of the
output shaft so when you zoom back out a little bit so you can see the whole thing here we go
one two
three and about a tenth more 3.1 turns of the input to get one turn of the output these
planetary gear sets by the way are huge compared to any other 1/2 ton and 3/4 ton one-ton truck
automatic transmissions these are monsters this transmission is a big heavy-duty transmission
everything is really heavy but it's a very reliable transmission it's been very very
trouble-free alright now it was first gear so that was holding the C5 clutch turning the C1
clutch in the rotating clutch module to go to second gear all we do is release the C5 clutch
and apply the C4 clutch we keep the C1 and the rotating clutch module turning so we have to
let go of the C5 go to neutral then grab the C4 clutch and this should give us 1.8
turms of the input to one turn of the output so here we go you see the output strung a little
faster there's one turn of the input and not quite a full two terms 1.8 1 to 1 gear ratio and we've
got one full full turn of the output so that's second gear to go to third gear we have to let
go of the C4 clutch and now grab the C3 clutch so we've just moved right up the planetary gear
set its first gear second gear third gear except now for third gear besides well know that's it
we're still going to turn the C1 clutch and this rotating clutch module now third gear has a gear
ratio of 1.4 to 1 so our output shafts should turn even faster so here we go I'll turn it we've got
one turn in and about 4/10 of a turn and we've got a full turn of the output so that's third
gear of 1.4 to one. fourth gear is direct-drive and direct-drive means one turn of the input
gives us one turn of the output and in fourth gear we let go of all three of these holding
clutches sometimes they refer to as brakes and instead we're going to apply will keep the see
one clutch applied and turn the rotating clutch module but now we're also going to apply the C2
clutch so that means all three of these pieces here are going to be hooked to the input shaft
and the whole thing will just turn as an assembly so here's fourth gear one turn in equals one turn
out okay now we're going to shift in the fifth gear to have fifth gear we need to apply the C3
clutch and turn the C2 clutch these parts are very heavy and difficult to turn especially in
the overdrive gear range and so let me line up there are sticker here to get fifth gear I'm
going to have to use a little helper tool here to help me turn that C2 clutch housing for overdrive
so we should have about 0.71 terms of the input there we go to one term of the output everything
is kind of on a bind here in these V blocks so it makes it more difficult to turn especially
in overdrive now sixth gear is actually double overdrive fifth gear is 0.71 terms of the input
to one turn of the output sixth gear is 0.61 terms of the input to one term of the output
and in sixth gear will let go the C3 clutch and we'll just go back to the C4 clutch and continue
turning with the C2 clutch and the rotating clutch module so now we should have less than half of the
input to get one full term of the output with the C4 clutch applied so here we go you can see that's
really spinning quickly on that output there we go 6/10 of a turn in 0.6 one turns in to one
turn out so this is the Allison 1000 transmission the internals we've got five clutches C1 plus C2
cuts C3 clutch C4 clutch C5 clutch we've got three planetary gear sets P1 P2 P3 this great big gear
right here is your parking gear where your parking pawl is going to come in and lock the output shaft
from turning there's monsterous bearings on the output gigantic torque converter on the input
this transmission is a very heavy duty and turning out to be a very reliable automatic transmission