Author Topic: basic clutch info  (Read 5761 times)

Offline Chryco Psycho

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basic clutch info
« on: January 19, 2005 - 03:28:45 pm »
Lets take a look a clutches
 there are a 3 of variables
from early 60 s to 69 there were 2 set ups for big blocks, small blocks used the 130 tooth
set up
 the 130 tooth flywheel using a 10.5" clutch for light duty applicatins from slant 6 -383 &
the 143 tooth flywheel used in 440 & Hemi applications with the 11" clutch
 in 70 they started using the 10.95 " clutch [commonly] refered to as the 11"] with a
scalloped pressure plate on the 130 tooth flywheel 
Even though both clutches are refer to as 11" Nothing will interchange Due to the flywheel
diameter & bolt patterns , the 143 tooth uses a cast iron belhousing & repositions the
starter away from the crank , the 130 tooth flywheel uses an alum belhousing with the starter
 closer to the crank , there is also a Thrid Belhousing used in the mid 60 Hemi applications
 that uses a direct drive starter instead of the usual gear reduction starter
 The Truck Belhousings for the 833 tranny with side shifter  will work in cars as well but
the truck bells for the A435 tranny with top shift will not work in car applications &
 the slant 6 bell is a totally unique again & the car & truck bells are different but can
 be made to work , the belhousing must also be matched to the front retainer size on the
833 tranny , the 23 spline had either 4.35 " or 4.80 " diameter , the 18 spline only used
the 4.80 , & the OD 833 used the 5.125 dia
  With the flywheels there are a lot of things to think about the slant ^ uses a differnt
 bolt pattern from the V8 & also uses a 10" clutch
 the V8 flywheels all use the same bolt pattern except the Hemi with 8 bolt crank flange &
use 7/16" fine threads bolt into the crank flange
as mentioned the 143 tooth flywheel uses a larger pressure plate with a wider bolt circle
the 130 tooth flywheel uses a pressure plate with the bolts so tight to the plate that
the plate is actually notched for clearance & it uses a special bolt like a header bolt
but with a shoulder to mount the pressure plate ALL clutches must be mounted using Special
3/8" shouldered bolts that recess into the flywheel with a 1/4" shoulder , using a regular
even grade 8 bolt can cause failure as the pressure plate can move against the threads &
hear the bolts off , generally this will make a mess , Usually a 10.95 pressure plate will
be supplied with new bolts when purchased. the other thing to keep in mind with flywheels
is balancing , the 400 , 360 , 440+6 were all externally balanced so you need to be sure
you have the correct flywheel for the engine, For racing I highly recommend going to a
 Blastsheild & a
Steel SFI spec flywheel over the factory cast flywheel mopar has both 6 bolt 130 tooth
P4529142  & the 8 bolt 130 tooth P4529143 available , I believe McLeod also has the 143
tooth steel flywheels available , the 360 6 bolt flywheel is also available P4529110 for
 the pre-magnum engines & P5249842 for the Crate & Magnum engine , for the 440+6 & 400
 you will need to locate a used flywheel or have the engine balanced with the flywheel
while building the engine
 There are also 3+ styles of clutch ,
1] the Diaphragm - This is generally used by GM & more recently the Cummins , it has the
lightest pedal pressure & is used in low HP applications for the most part [except Cummins]
they have 18 fingers where the release brg pushes on it clutch , there are no springs just
a single plate stamped into a cone shape , Dynapack kits & Centerforce are selling these
virtually exclusively now & I am not a fan of them  I have seen may of them fail or slip
 the only reason they survive in the Cummins is because the clutch is generally engaged at
 idle &  it has a massive 14" disc with huge surface area , start abusing the cummns at the
 track or towing & the will fail rapidly, also at high rpm the clutch may stay released &
not return to clamp the disc , I hope you have a rev limiter !!!
2] the 3 finger Borg & Beck style , this is what was used from the factory they have 9-12
springs & these can be changed with lighter or heavier springs to adjust clamping pressures
but have higher pedal pressure & are available new from Mopar P4529141 for the 10.95 , I
recoomend using these in virtually any application as the cost is similar & the extra
surface area will help life & load carrying ability.These also have the advantage of using
 rollers inside them to increase plate pressure with Rpm , if you shake the PP & it rattles
 it has the centrifical rollers in the plate
3] The best style is the Borg & Beck Long style , the only source for this is McLeod , it
is a hybrid being & B&B stytle but using the long style levers mostly foundin  ford
applications , it is also designed with 9 - 12 coil springs but the release levers are
longer so the pedal pressure is reduced & the clutch releases faster too. The release arms
 also have provision to add extra weight to increase centrifical loading with RPM , these
are more expensive but well worth it in the right applications
4]Last there are multi disc clutches , by using 2 discs & a separator plate the surface area
 is doubled so without increasing pressure more power can be transmitted through the clutch
these systems are not cheap at around $1000 but in talking with clutch manufacturers some of
the engine being built recently are exceeding the ratings of any single disc clutch available
There are also a number of choices for clutch discs I won`t even begin to guess how many
types of linings are available for them , but basically there are the fiber discs at the
bottom , next the metal imprgnated which will withstand more heat , Kevlar [looks like
 cardboard !!], Ceramic , & the feramic [Velvet touch ] which is far from it . I
 recoomend using at least the metal imprgnated discs , the feramic are truly violent , on or
 In My duster with traction I ate 2 discs in under 500 miles & installed a feramic , it
lived 8 years Racing a street driving & pulled the front wheels with ease , when I installed
 it it was bronze/ gold color , when I removed it it was B5 Blue from heat from slippage but
 was not worn at all it hadn`t even made full contact on the pucks on the disc
 Next we need to consider the release brg , there are only 2 , due to the different diameter
 of the input shaft between 23 & 18 spline trannys you need to matching brg
the SKF XXXXXX is the 23 spline brg , it is easy to get & only $35 or so
 the P4529064 is thew 18 Spline Hemi brg this is obsolete from everyone except Mopar & is
over $100, SKF does have the brg without the iron sleeve though #N1181, you will need to press
 the brg on & off
There are 3 clutch forks available , A body A engine P 4529451
B body A engine P4529452
B body B engine P4529453
 all these use the flat angled pivot , the truck belhousings use a ball pivot & different fork so
keep them together
 Clutch adjuster rods are available from Mopar as well
 A & a P4529448. B & A P4529449 , & B & B P4529450 but they are expensive
 also available is offset dowels to center the belhousing so the tranny is in line with the crank
part # P4120383 , if using a blastsheild these are a must
 Pilot bushing should be checked & at least greased while it is apart
Part # 53298 from mopar , it is so old it has a 5 digit part # !!or part # PB286 from Pioneer
 the alternative is the Dakota roller brg Part # 53009180AB from Mopar it fits into the torque
converter support in the rear of the crank
 As a side note I do not know of any repro Steel covers for the bottom of the belhousings , the
 Truck wrecing yard ones will work for small blocks 

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Offline greenzeppelin

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Re: basic clutch info
« Reply #1 on: May 09, 2012 - 02:40:41 am »
release bearing number is SKF # N1463 for 23spline

1973 Dodge Challenger 340, 4spd, 18x8 & 18x9.5

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Offline slsc98

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Re: basic clutch info
« Reply #2 on: January 14, 2013 - 09:50:07 am »
CP, good morning! This morning marks the umpteenth time I have "come back to" this post and I just felt the need to post a "shout-out" and huge Thank You! Having quick access to this comprehensive info has not helped me trmendously but, I have actually referred numerous others to it, as well. This forum ROCKS!   :jumping: