Clutch pedal return

[edison1970]

When I let out my clutch, the pedal returns to the top with a hard thud. Any thoughts on how to fix it? I can't imagine I have the wrong spring.

[Cuda Cody]

What pressure plate are you using?

[edison1970]

It's a Hays Street Strip pressure plate.

[Chryco Psycho]

HOw much free play do you have at the top of the travel , you may not have enough depending on the adjustment

[Shoooter]

There are a few different ones out there of the hays. If there is a bunch of fingers on the plate you dont need the spring I belive. If there is only 3 then you need to run the spring. Correct me if I'm wrong???

[YellowThumper]

Spring has an over/under pivot point. Most replacement pressure plates will have the multiple stamped fingers. This style does not require the same amount of movement for release. They can work as I have that style on mine. I just adjusted clutch position so it retracts past the center. This does then have a lot of free play up top.
"Correct" style is the 3 finger style as previously noted. The movement of that style plate is what the linkage is setup for.

[edison1970]

It's a 3 finger. As far as free play, that is the distance of travel before the release bearing touches the fingers on the pressure plate, correct? I wish I could post a video. I can't seem to get it to post.

[Chryco Psycho]

yes , the pedal should move 3/4 of an inch before you feel the pressure of the clutch add to the oressure needed to depress the clutch pedal

[70 Challenger Lover]

I had the same issue on mine. You can adjust it to work but I was personally never happy with the feel. To get the clutch to engage so it's not at the very top of the pedal stroke, there is a thud at the top caused by the over center spring. You can adjust it for less thud but then the clutch engages near the top of the pedal throw which isn't very comfortable.

On the car I'm building now, I am considering ditching the over center spring and using a diaphragm style clutch instead. The over center spring assists the pedal in both directions though and without it, I'm wondering if there is a need for a small return spring to make sure the pedal returns to the top and doesn't keep the throwout bearing engaged.

[edison1970]

You hit the nail on the head. It makes that "thud" when it hits the bumper. It's almost like the over the center spring has too much tension. If I adjust the clutch to make it better, I  lose my freeplay. I'm almost tempted to heat the spring with the torch and stretch it a hair. My only concern is it may weaken the spring and possibly break under load.

[Chryco Psycho]

you could change to hydraulic !

[edison1970]

Maybe some day! 🤑 No green on the tree to spare right now. 

[70 Challenger Lover]

Personally, I think it's a poor design. The Borg and Beck three finger pressure plate is so strong that the over center spring is needed to assist in pressing the pedal down. I have driven lots of GM cars and they use a return spring on the pedal linkage along with a diaphragm clutch. I think it works nice because you can adjust the clutch to engage close to the floor for comfortable and fast shifting. There is tons of free play for the throwout bearing as the pedal returns softly to the top with only the small return spring helping it along.

I think I may switch to a hydraulic clutch on my current build since the car will have some other aftermarket upgrades.

[Topcat]

I recall when mine had the dreaded "Thud" and pedal not returning.


I was using the Hays B & B as well.

Switched to Mc Leod Borg & Beck.
Not a big deal on pedal effort on long drives or city driving. 

Some things I did this last time and it may have helped?

New Over Center pin the Spring hooks onto.
Prior one was worn with a crater/divit.
The Z bar nylon bearings: O rings to keep them tension'ed together with Lithium grease. 

Lastly, I used an up grade pivot ball.
Rick claims it's a problem solver on no adjustments required as much.
Brewers might even carry this part as well.

https://www.ebay.com/itm/Mopar-Clutch-Linkage-Upgrade-A833-340-383-440-Dodge-Dart-Coronet-Satellite-Dustr/323783892590?_trkparms=aid%3D111001%26algo%3DREC.SEED%26ao%3D1%26asc%3D20160727114228%26meid%3D99bae66f747744ed8a170e6d3efce53d%26pid%3D100290%26rk%3D1%26rkt%3D4%26sd%3D323783892590%26itm%3D323783892590%26pmt%3D0%26noa%3D1%26pg%3D2060778&_trksid=p2060778.c100290.m3507 

[70 Challenger Lover]

I did all those things on mine and the whole system worked great. If I adjusted the clutch so it engaged at the top of the pedal, there was no thud but it sucked trying to feather the clutch so far off the floor. If I adjusted it so it engaged close to the floor then the pedal wouldn't get over the hump on the over center spring so the pedal remained halfway down which kept constant pressure on the throwout bearing. The only solution I found was to adjust it halfway and live with the thud.