Yet another 4106 clutch pressuge plate question

[fortyniner]

Seeking opinions on leaving out one spring of each four spring cluster on pressure plate to reduce stiffness.

The clutch on my current 4106 is pretty stiff. More than my first 4106. I went through the adjustment front to back including mousetrap and its a lot better but still a bit of a beast. 

Looking at the receipts I see clutch was replaced by Steves Truck Service at some point. I suspect the pressure plate is for some truck and much stiffer than the original one.

The clutch also has some shuddering unless I slip it more than Id like. Not certain what causes that.

[tr206]

Taking springs out you will cause your clutch to slip. You may have a button clutch if it shudders a little.

[chessie4905]

Pressure plates with diaphragm  fingers (thin fingers all the way around the plate) require less pedal pressure than 3 or 4 finger designs. Also as clutch plate wears, fingers get more and more off center and require increasing pressure to depress pedal. Some swear the mouse trap assists are great, but the mechanism uses a lot of room by the trans. We had an air assist style on the 4104 and pedal pressure was light.There was an air adjustable regulator to set pressure. Pretty compact.

[fortyniner]

Is a diaphragm pressure plate available for the 4106 clutch? The old manuals all show the level type.

[tr206]

How about your clutch linkage could it be binding or worn out? I would unhook it at the bellhousing and see if its smooth and easy action. Not familiar with a 4106 is the return spring or springs the right ones maybe to strong?

[chessie4905]

I would check all the linkage first. Rusted belcranks from lack of grease could be your problem. Unhook at  clutch release arm and move pedal at front to see if it easily moves.

[fortyniner]

The clutch moves easy when disconnected from the release arm. Ive greased every point in the linkage. As expected the eyes in the bellcrank are somewhat elongated.

BTW, I replaced the drivers floor with 5/8 marine ply due to rot and distortion around the clutch and electrical areas. Now I can actually set pedal height. That was a fun job.

But going back to the original question I wonder if there is difference between coach and truck pressure plate springs?  I know a truck shop did the last clutch job and the PO has a air cylinder pulling down on the clutch pedal arm! 

Im fixing to move up to Colorado where Ill have a proper workshop so Ill just live with  it for now.

Ill update this thread next spring when I get down to it for everyone's future reference. 

[richard5933]

There are differences in brake linings from truck to coach, so it makes sense that there are differences in clutch linings as well. Truck clutches are designed for much heavier loads.

Do you have the paperwork from the clutch job where you can look up the parts they used?

[luvrbus]

Trucks never used that type double disk clutch the only place you find that clutch is on GM's and early MCI's .They are both easy to change to the mushroom, the holders for the center plate are just bolted on the flywheel so you can use the same flywheel.A hydraulic assist is easy to install using the existing clutch rod it all mounts at the transmission and can be done with minimum fab skills using a old style master cylinder ( 60's and 70's era from a Ford) and a slave cylinder from a later model truck 

[fortyniner]

Good to know on clutch.
What does that mean: "They are both easy to change to the mushroom... "

Do you mean swap out mechanical for hydraulic?
"A hydraulic assist "

I can fab stuff and have been wondering about hydraulic conversion.

[luvrbus]

Both the GM and MCI are easy to change over if you want a mushroom type hydraulic assist will cost you 50 bucks for the old single line master cylinder (new) the slave cylinders are around 30 bucks if you can fab that is way to go and keep you clutch.Hydraulic assist clutch pedals have been around in trucks,cars and buses for years now 

[fortyniner]

Sure Ive worked on plenty of hydraulic clutch setups in cars and light trucks.
Does mushroom type hydraulic assist refer to the throwout fork pivot? 

[fortyniner]

Oh mushroom is the single plate style.  Yeah if hydraulic update restores clutch action Id prefer that for sure.

[fortyniner]

Dug out my old HP 1030 book: clutch and flywheels. Mushroom == diaphragm style. 

Anyone have part numbers for the mushroom clutch setup handy? 

This will be a good SPRING project haha.