10.5" Sintered Iron Long Style Clutch Assembly
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I thought I would take a little bit to show everyone what a basic rebuild looks
like and what changes can be made to effect the different setups.
To
start off with let me explain the uses and pros/cons of the Long Style clutch.
There are 2 versions, counter weighted and non counterweighted. Also you can go
to dual disc as well.
Basically the Long Style or "Softloc" type of
clutch is good for applications that are in need of being able to control the
slippage of the clutch througout a given rpm range. To really take advantage of
the counterweight and base you need to run some type of data logger, however it
isn't 100% necissary. The data logger can show you if you need to add or remove
counterweight or base. Understand that a clutch is effected more by rpm and the
chassis's ability to hook than by the horsepower.
FOR EXAMPLE - If you
are launching a car at 5000 rpm, and you are shifting at 7500, then we will
conclude your engine makes it's best power just under 7500 rpm. So the quicker
you can get the engine to that rpm range and keep it there... the faster and
quicker you should be able to run. When you look at a long style clutch that
doesn't have counterweight, you are relying on the springs to hold the SAME
amount of pressure on clutch through the entire run. This means you pretty much
have to lock it up at the hit and there is no slippage during the run. With a
counterweighted version, you would be able to start with less base, allowing the
clutch to slip, but as the engine gains rpm the counterweight has more leverage
and is able to apply more and more pressure to lock it up. This is why short
shifting with this type of clutch can hurt the run, because you didn't give the
counterweight enough time to lock up, which causes the clutch to slip accessivly
during the shift and it is hard for it to catch back up.
The clutch shown
here is a RAM Single Disc 5135 disc sintered iron Long Style clutch with
counterweighted fingers. In this build we changed the fingers to a type that
allows for more adjustability as well as lightened and rebalanced them. Making
the fingers light doesn't mean as much as making the balance correct. If you
have the finger weighing more on the inside of the pressure plate, than on the
counter side, then it takes more counter to do the same job, which allows for
greater adjustability in lower hp and more traction applications.... which are
common!
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Above you see all of the parts and pieces layed out for this clutch. There are
springs, levers, pins, yokes, disc, flywheel, pressure ring, and hat, as well as
base adjusters.
To start off we go through and clean everything up as
best as possible and inspect all pins and levers that they are not seeing
excessive wear. Often times we can chuck them up in the lathe and polish them,
so that the customer doesn't have to spend extra money. Then we surface the
faces of the flywheel and pressure ring as well as cut the clutch disc with the
diamond cutter on the clutch machine. It is highly important to be sure that all
surfaces are flat before you begin.
Here is a picture of the flywheel
before any surfacing has been done.
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You can see that there is a a little bit of heat spots towards the inner
circle... This is normal and is not a bad looking start. It is showing that it
is wearing across the entire flywheel, however that could also mean (which in
this case does) that the disc itself was wearing in a certain pattern that
matched the flywheel.
When we took a machinists straight edge and looked
at the flywheel, you could tell it was definately high on the outside edeges,
and very low in the middle as seen below!
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After surfacing the flywheel and getting it flat, we mic'ed it and felt it was
good enough for one more go before the heat shield would need replaced.
This meant it was time to look at the disc and upon inspection it was
definately wearing more on the outside of the disc than in the middle, and we
used a new disc. I was able to cut the previous disc, however it was down so
thin that it wouldn't last long and would require a lot of shiming to make it
right upon setup. As well as it wouldn't last more than 15-20 runs.
Upon
replacing the disc we also replaced the pressure ring on the hat, however most
times a simple resurface is just fine. In this case the customer wanted a new
one, so that is what we went with.
Now that all of the surfaces are flat
we can begin assembly. We cleaned and repainted the pressure hat, as well as
polished the pins, lightened, and rebalanced the fingers. To start assembly we
take the pressure ring and place the springs (in this case 360 lb / yellow) in
the spring cups.
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Then we place the base adjusters ( 2 part - Aluminum base piece with steel bolt)
into the tops of the springs. As well as re-insert the fingers with the yokes
attached along with new codder pins and polished shafts.
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Now it is time to add the hat to the pressure ring. The best way to do this is
to place the pressure ring on top of the disc and flywheel, then lower the hat
down onto the springs and line them up, dropping it down onto them. By slightly
starting the nuts to hold the had onto the flywheel you can compress the springs
a bit which will help you get the bolts through the cover and into the yokes of
the fingers... However, this is where setup begins. How you shim the fingers
makes a great difference in how the clutch will work. By placing shim stock
under the hat between it and the top of the yoke, you can raise or lower the
levers. You measure this distance by placing a flat edge across the inside edge
of the hat, and using a mic, measure the distance down to the edge of the finger
at the lowest point. In this case we added to the typical setup and made the
fingers slightly lower to start with releasing a bit of pressure.
Here
is a Die we use for stamping out our shim stock...
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Once we have the fingers approximately where we want them we can lock it all
down... however we also had to calculate the shims that are placed under the
hat. By placing more shims there, you are putting less base pressure on the disc
initially. However as the disc wears it will require the user to slowly add more
and more base to the clutch in order for it to perform the same way. This is
where a Full Billet Adjustable Pro clutch comes in and we can adjust the stands
which adjust for the wear of the discs and floaters.
Here we have the
clutch before the finger height has been set or the cover bolts put into
place.
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And the finished product with everything set and ready to roll here.
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I hope some of you find help with this, and if there are any questions or
interest, please don't hesitate to ask!
We will soon work on a pictorial build with Pro Billet Fully Adjustable setups too.
Cale@GoFastQuick.com 660-646-4553
Thanks,
Cale Aronson
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