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#1
02-19-2016, 12:40 PM
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Thoughts on heavy clutch despite being hydraulic?
Just completed TKO 600 swap including hydraulic clutch.
The trans shifts nice and smoothly, no issues of any kind from what I can tell when I listen and drive. However... the clutch has a very heavy feel. Like factory 4 speed feel. I guess I wasn't expecting this with a wilwood master. The pedals are factory replacement clutch / brake. Any thoughts on what could be causing this? Or was my expectation to have a light clutch too much to ask? I'm not the most knowledgeable on manual trans / clutches if I'm honest, but managed to get this sucker installed and driving nicely. Alternative is just leaving it since it drives well, but not the preferred outcome. Thoughts? |
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#2
02-19-2016, 12:43 PM
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I have never found a hyd any easyer,I only use one when good mech linkage is not avail.I know there is a relationship between the size of the MC diameter.I had one where it was too large and could hardly push it in.Tom
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#3
02-19-2016, 12:46 PM
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Get a smaller master cylinder.
__________________
1979 Trans Am WS-6 .030 455 zero decked flat pistons 96 heads with SS valves 041 cam with Rhoads lifters 1.65 rockers RPM rods 800 Cliffs Q Jet on Holley Street Dominator ST-10 4 speed (3.42 first) w 2.73 rear gear __________________________________________________ _______________________________ 469th TFS Korat Thailand 1968-69 F-4E Muzzle 2 |
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#4
02-19-2016, 01:01 PM
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Quote:
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#5
02-19-2016, 02:18 PM
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Yes.
__________________
1979 Trans Am WS-6 .030 455 zero decked flat pistons 96 heads with SS valves 041 cam with Rhoads lifters 1.65 rockers RPM rods 800 Cliffs Q Jet on Holley Street Dominator ST-10 4 speed (3.42 first) w 2.73 rear gear __________________________________________________ _______________________________ 469th TFS Korat Thailand 1968-69 F-4E Muzzle 2 |
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#6
02-19-2016, 08:58 PM
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Tom is right - the mechanical McLeod clutch on my Lemans is actually easier than the Ram hydraulic unit on my TA; neither are too strenous.
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#7
02-20-2016, 05:57 AM
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Performance clutches are going to have a stronger pressure plate which requires more force to release.
How much effort is required to push the pedal is a function of the pressure plate, pedal ratio, and master cylinder bore size (slave cylinder size too but that's not typically changeable). A smaller master will require less pressure at the pedal, but more pedal travel to move the same amount of fluid. My 89 TA has a LS1 and t56. I have a Monster stage 2 clutch in it with a Tick 4th gen master cylinder, which is a bigger bore than stock. My 01 TA is stock. The 89 requires a lot more pedal effort but I actually prefer it. After driving my 89, my 01 feels too light. It seems like a lot of people complain about a stiff clutch because it's too much effort to hold the pedal down. If you are in the habit of holding it down at stops, then get in the habit of putting the car in neutral and releasing it as much as possible. Holding it down puts un-necessary stress on your hydraulics, throw out and pilot bearings, as well as your crank thrust bearings. If you just can't get use to it as is, then look at swapping to a smaller bore master.
__________________
67 Firebird http://www.pro-touring.com/showthrea...ird&highlight= 68 Firebird, 69 Firebird, 79 TATA, 89 GTA LS1 t56 swap, 01 WS6 6 speed |
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#8
02-20-2016, 09:50 AM
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What size master cylinder?
If the pressure plate is above 2500-2600 lb clamping force, a 3/4" master works really well. |
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#9
02-20-2016, 10:01 AM
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That's interesting, used a Wilwood master ( thinking 1/2 inch but not 100) McLeod throwout. Used stock pedal assembly with stock pivot point. Made a push rod out of aluminum bar and a hiem joint. Clutch is twin disk 10 inch.
Feels like a brand new sports car clutch, feather light. Is something binding? Steve Ps. I did add a support from master down to frame because fire wall had some give Pss. You don't have any return spring on your pedal do you?
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462 Yc Block, zero deck Probe forged pistons 6cc relief, Scatt Hbeam rods floating pins aprox. 10.21 CR Comp Hyd-roller cam,roller lifters,springs ect. 236 244@ .050 108 LSA .511 lift, duration 289,297 @.oo6 Edelbrock Aluminum 87cc round port heads Larger valves ,ported polished and cut Powerjection3,T2 manifold, Try-y’s Flowcooler water pump. 71 formula with TKO600,hydraulic clutch 3.42 posi and 26 inch tire. 17x9 YO Honeycombs with Nitto 555's Last edited by lfdsteve; 02-20-2016 at 10:23 AM. |
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#10
02-20-2016, 10:30 AM
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I doubt it's a 1/2" bore, can you double check it?
It is also possible with a factory linkage that you are over centering the pressure plate. |
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#11
02-20-2016, 10:51 AM
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Quote:
When you sit at a long light and there are some intersections where the light does not change for MINUTES, get in the habit (as was mentioned) with putting your foot on the brake and putting the trans in neutral with your foot off the clutch pedal. Throw-out bearings were not designed to be under a load for minutes at a time. It boils the grease right out of them. Same deal again, as mentioned, with the Thrust Bearing load in the engine and the side load on the pilot bearing on the crank/input shaft of the trans. Tom V.
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"Engineers do stuff for reasons" Tom Vaught Despite small distractions, there are those who will go Forward, Learning, Sharing Knowledge, Doing what they can to help others move forward. |
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#12
02-20-2016, 10:55 AM
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Quote:
Steve
__________________
462 Yc Block, zero deck Probe forged pistons 6cc relief, Scatt Hbeam rods floating pins aprox. 10.21 CR Comp Hyd-roller cam,roller lifters,springs ect. 236 244@ .050 108 LSA .511 lift, duration 289,297 @.oo6 Edelbrock Aluminum 87cc round port heads Larger valves ,ported polished and cut Powerjection3,T2 manifold, Try-y’s Flowcooler water pump. 71 formula with TKO600,hydraulic clutch 3.42 posi and 26 inch tire. 17x9 YO Honeycombs with Nitto 555's |
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#13
02-20-2016, 11:15 AM
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Mock up...
 Setup...  Clutch...  Car... Old pic. It's just about finished now. 
__________________
462 Yc Block, zero deck Probe forged pistons 6cc relief, Scatt Hbeam rods floating pins aprox. 10.21 CR Comp Hyd-roller cam,roller lifters,springs ect. 236 244@ .050 108 LSA .511 lift, duration 289,297 @.oo6 Edelbrock Aluminum 87cc round port heads Larger valves ,ported polished and cut Powerjection3,T2 manifold, Try-y’s Flowcooler water pump. 71 formula with TKO600,hydraulic clutch 3.42 posi and 26 inch tire. 17x9 YO Honeycombs with Nitto 555's |
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#14
02-20-2016, 11:38 AM
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Nice 71!
__________________
 ___________________________________ "Objects in mirror are closer than they appear" 
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#15
02-20-2016, 01:06 PM
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Am I seeing things or did you really use a TEK screw into the booster? I also note you used a NPT/AN fitting instead of the weak piece Wilwood supplied.
 We make a Wilwood mount for the 70-81 F's also: |
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#16
02-20-2016, 02:17 PM
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Beautiful car.
Check to make sure it's not over centering the pressure plate. Other than that, it shouldn't be that hard to push. |
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#17
02-20-2016, 05:43 PM
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Setting the release distance between the flywheel/clutch disc/pressure plate (using a feeler gage) is pretty easy. Getting the right setting with a hydraulic unit takes a bit more effort. So how do most people find the correct shim to get the release and not a over-centering on the pressure plate? Always wanting to learn new things.
Tom V.
__________________
"Engineers do stuff for reasons" Tom Vaught Despite small distractions, there are those who will go Forward, Learning, Sharing Knowledge, Doing what they can to help others move forward. |
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#18
02-20-2016, 05:59 PM
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My thoughts were scattered today while typing the other responses and I should have taken more time to answer correctly.
Overcentering the pressure plate is usually because of factory linkages and pressure plates that were not designed for the car to begin with....i.e. a 60's Ford with a factory linkage and a diaphragm pressure plate....etc. I should have thought more about that before I answered, but I will reneg on my answer about over centering with the hydraulic setup. If it's a hydraulic slave cylinder, then you adjust pushrod length/travel. If it's a hydraulic throw out bearing, then most of the higher quality bearings have an adjustable bearing, or you measure and get the correct piston for the bearing. If the OP is working with a 3/4" master, then IMO the bore size is optimal. Only other thing I can think of, is where the pushrod is connected to the clutch pedal and how long the pedal is. Could be a leverage-type thing... I sell a large quantity of the twin disc clutches, mainly from McLeod....their RST and RXT lines are very easy on the clutch leg and are generally easy to setup. As a general rule, most aftermarket clutches are easier on the legs than they used to be in the 60's/70's. You don't 2800-3000 lb clamping forces anymore; they are generally around the 1800-2000-2200-2400 lb mark. |
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#19
02-20-2016, 06:02 PM
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Can you over center a B&B PP?
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#20
02-20-2016, 06:03 PM
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Most of my experience is in diaphragm and Long styles, but I have never heard of anyone over centering a 3-fingered plate of any style.
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