I have a '66 442 with an M21 close ratio. I also have a 425 with tripower. I understand the engine has a W30 cam in it. It does not like to start off at an idle which is what is causing my problem. I have to ride the clutch to get it moving and I think I have caused glazing on the clutch as it has begun to "judder" a lot when starting off. When I bought the car I was told that my differential ratio was 3:55. When I had the car apart for the restoration I checked by turning the driveshaft and counting wheel turns and I thought it was 3:90 or 4:11. During the restore, I had the transmission rebuilt, turned the flywheel, and put in a new stock clutch according to the specifications of the car. I have not driven the car a lot of miles since the restore and I have not been hard on the clutch.
I drive big truck on the highway so I do know how to use a manual transmission and clutch.
Does anyone have a solution to my situation? If I had bags of money I would put a 6 speed Tremec with a low first gear and I know that would solve the problem but is there anything else I can do? Would a ceramic clutch face be a solution?
Thanks
Pat Mills

 

A M-20 would be a better solution.
Did that same swap on a '67 BB Impala last year, with a 3:42.
Owner didn't believe it was the same car!

 

Thank you - didn't think of that.

Pat

 

Let us know how it works out!

 

Will do. Would you use the stock clutch? If not what would you use?

Thanks

Pat

 

You could just 'break the glaze' on all parts - I'd think, being new, it should be OK.
Some don't realize that getting your foot off the clutch asap adds longevity!
Don't slip it - let the motor do the work!
And if it slips when you 'stand on it', clutch fully engaged, somethings not right!

 

Thanks again for the advice and yes I fully appreciate what riding the clutch does.
How would you "break the glaze" ?

 

80 grit on a sanding block powered by elbow grease!!
All contact areas.
Didn't mean riding the clutch - meant getting it fully engaged asap, without or with very little slippage!

Once had a neighbor with a 300 Z, asked him how he liked it - he said "fine, but he was on his 4th clutch in 60k miles!"
Heard him take off once, and he slipped it almost all the way through 1st!!
But he was one of those guys you couldn't say anything to, so I didn't.

Another friend put 140k on his ford ranger clutch - but knew how to drive stick.

 

Thanks for the information. And I fully agree with you about using a clutch properly.
With a big truck you don't touch the fuel til you have it rolling with the clutch right out.
Am going to try and find a M-20.

 

Sometimes if the adjustment is not quite right, pilot bearing worn, throwout bearing worn, weak pressure plate, will cause a chatter.

 

If you can't find an M20, you can change the first gear in that M21 to a 2:52. The shop that rebuilt the trans. can do it and may even have the gear.

 

Well you always must increase the rpm/pedal pressure while getting the car to start from a stop. If you try and do it at idle speed it will stall or you will need to "ride the clutch". I assume the rpms come up normally when in neutral and pressing on the accelerator. With a w30 cam I would have my idle speed at about 950 rpm or so.

 

Thanks for all your suggestions. I am going to try and trade my transmission for a M-20 because Reverse in a M-21 is really high too.

 

If your rear gears are 3.90 or more, an M21 should work real well. Your clutch should be fully engaged at only a few MPH. (I have owned a 66 with that exact configuration). I would suspect the pressure plate. Is it a stock diaphragm, or a Borg & Beck style with the 3 arms? The Borg & Beck style can get out of addjustment, and if the plate is not meeting the disc evenly, that will cause chatter. Glazing usually causes slippage rather than chatter, and can be cured with some elbow grease as noted. (you do have to pull the clutch to do it)

 

So the engine is running fine? Not feeling like it wants to stall?