high speed clutch chatter

[Martin]

I'm fairly new to Model T's. I have a 1916 runabout with a 1922 engine and trans. Since I've owned it the clutch has chattered a bit when going from low to high. I have only driven it a little bit (maybe 50 miles) but the chatter seems to be getting worse. Should I try adjusting the three screws on the pressure plate?
Martin

[speedytinc]

Chatter is a bit odd.
I have not experienced a chatter in the transition from low to high.
Chatter is normally associated with engaging low with hard band lining like wood.
The problem is usually extra slippage & yes, readjusting the 3 finger screws will fix this.
Per T1 service manual. Get it & read it. The T1 manual will answer most issues.

[Norman Kling]

When you let out the clutch to high gear, you should estimate the speed of the engine would be going after it is in high hear. This way the drive disks and the driven disks are going at the same rate. So if you have revved up in low, raise the throttle to nearly an idle and then let out the pedal quickly. The clutch should not be allowed to slip into mesh as would be the case with a modern stick shift. If the clutch does not slip when running in high gear, leave it alone. If it slips, you will need to do some adjustments. If shifting down into a lower gear, first slow down as much as you can in high and then while you shift down pull the throttle down to speed the engine to the speed it would be going when in the lower gear. Pause momentarily as you pass through neutral as you rev the engine.
What I have posted works for a stock clutch. It might be different for a jackrabbit clutch or a watts clutch. Those two aftermarket clutches have soft lining on some of the disks and slipping will wear them out.
Norm

[Moxie26]

Does the chatter occur with low, just before going into high? If so, the low band needs one turn tight. If the chatter occurs after high speed engagement.the three screws on the clutch plate may need a turn. If you add excessive ATF or marvel mystery oil to your engine oil that may attribute to the chatter/slip. Engine oil, of course, is your choice, I get better results with 10W30 synthetic, and I have had wood bands the last 20 years. Anyone's choice comes about from experimentation.

[Martin]

Moxie,
Low is fine, but it chatters when I let the pedal rise up from neutral to high. I'm using 10W30 conventional engine oil.
Norman,
I try to match engine to car speed (I double-clutch sliding gear transmissions pretty well) but if I miss it by just a bit the chatter is pretty severe.
Speedytinc,
No slippage, no chatter in low.

Thanks to all

[Mark Nunn]

If a slight rpm difference causes chatter, I would look for clutch lug wear. Disks could be snagging on lugs preventing even pressure.