Hays Adjustable Pivot Stud And A Helicoil To Fix A Hard Clutch Pedal

Good Morning all. I’ve been trying to fix a hard clutch pedal on my 1971 Cj5 for sometime now. The 71 as many of you know has a longer bell-housing which puts the pivot point and ultimately the throw out bearing surface farther away from the clutch diaphragm. In order to get the clutch to work properly, I’ve had to raise the cable connection point to a higher spot on the clutch pedal to get enough cable travel. This works, but increases the effort needed to push the clutch pedal.

I’ve seen other posts where users have fixed this issue by using a longer, adjustable pivot stud. I have ordered a Hays adjustable and after a few months received, this Hays adjustable pivot stud. The threads on this stud are 1/2-13 (as were many of the other choices).

The Bell-housing is tapped for the original stud (which is now way to short) for 7/16-16 (I believe). I don’t think there is enough bell-housing material to retap the hole to accommodate the larger diameter adjustable pivot stud.

My question is; what do you guys think of drilling and installing a Helicoil designed for a 1/2-13 bolt?

As always throughout this lengthy Jeep project your input has been in valuable and greatly appreciated!

 

Sorry I screwed this post up and deleted the wrong one.

I did see one question about replacing the clutch. Yes a previous owner had replaced the three fingers with a diaphram clutch. I’ve since replaced that as well

sorry for the posting issues

 

Seems to me that if you moved the cable higher up on the pedal arm you would have increased your mechanical advantage and so should have made it easier to push the clutch pedal down.

Somewhere around 6-7:1 is the typical mechanical advantage for a non assisted clutch pedal. Example.....the distance from the bottom of the foot pad to the pivot point on the pedal is say 12 inches. The distance from the pivot point to where the cable or rod attaches should be like 2" or so.

I went through this sort of thing with my JEEP and an old and highly respected member here helped me resolve my issue. The numbers above are what he told me. I have a hydraulic clutch though and that ratio is a little less than your mechanical set up should be .

Extending the ball stud, and so the fork, farther toward the clutch disc will not gain any mechanical advantage. A longer clutch fork ( longer at the area outside the bell and on that side of the ball stud ) will gain you an advantage. Extending the ball stud would, I think, only affect how the clutch engages and disengages and how the throwout bearing slides on the input shaft. In my case ( and long before I ever tackled and remedied the hard clutch pedal), my bearing was not sliding far enough inward toward the clutch disc and so would not fully disengage the clutch and the bearing seemed to get bound up on the shaft. I used a longer ball stud to get it working correctly.

 

Not very familiar with your problem, but just thinking. I have read somewhere, probably on here where the throwout bearing mount or sleeve can be changed to a longer one that places the ears for the fork farther toward the rear. Again just thinking, I may be way off on this.

 

I ended up using both the adjustable stud (modified) and McLeod's adjustable length throwout bearing (16505-https://www.summitracing.com/parts/mcl-16505) in my 3B to get everything properly functional. That throwout bearing ended up set to its longest length. I used McLeod's RST twin disc clutch for this go-around and will say the pedal effort on those is way less than the 11" Hays versions I previously used, both B&B and diaphragm styles.

If you have access to a lathe, you could turn that stud down to 7/16's and rethread.

 

That’s sounds great, I wish I had access to a lathe or new someone nearby that does. I hate to drill out the bellhousing if I didn’t need to. If I can’t find anyone, do you think the Helicoil would work?

 

Depends on how much material is there but I suspect if going from 7/16-14 to 1/2-13, you could just re-tap the hole. 7/16's is the usual tap drill for 1/2-13. No Helicoil necessary.

 

I have this same T shirt. Novak has GREAT instructions on setting up their adjustable throw out bearing. Yes, I know you have an adjustable stud. The set up process and measurements are the same. I had to use an adjustable throw out bearing and stud, Both can be used to set the proper clutch arm angle. BE PATIENT, I had over a week setting mine up, 350/ax15. Let me know if I can help. Ron

 

GM adjustable stud has the correct threads but it doesn't look as long as the Hay's piece.

 

Thanks, I’ve got Novak adjustable bearing and with the original pivot stud is still short. They also list numerous different other bearings. I got the longest one they list and it still comes up short. Hoping this or some other adjustable stud gets me closer.

 

I’ll take a look. I don’t need one as long as the hays, so maybe there is one with the same thread length that will be longer than the original. Hays listed this for GM cars, Pontiac, Chevrolet and I believe Buick

 

What are your measurements? The fork angle needs to be towards the front of the engine. There was an instruction sheet that showed the angled that was needed. I started by setting the throw out bearing height first, then set the angle of the fork. We can work this out, Ron

 

I’ll get some measurements for you. If I recall correctly, the fork is slightly angled forward. I’ve got to figure out how to move the whole setup closer to the clutch

 

From what I am seeing, the piece that threads in to the bell housing is 13/16"-16. Some of the brands were not made well. Your picture
doesn't show the bell housing piece. The throwout bearing is different for the borg and beck{finger type} clutch cover and the diaphragm
cover. It took me a bit to get the correct throw out bearing length and pivot ball combination and I used an adjustable pivot. To do it again, I would
use a long pivot as there is less to come apart.

https://www.chevelles.com/attachments/clutch-fork-angle-measure-method-1-pdf.614598/ For reference
https://fortesparts.com/product/clutch-fork-pivot-ball-gm/ They list two lengths.
https://www.summitracing.com/parts/nal-3790556 5/16" longer
https://www.summitracing.com/parts/mrg-3855g What I used.

 

If all you need is a longer ball stud. Why not make it yourself. Do you have a bench grinder? Buy yourself a new 7/16 grade 8 bolt in the length you need. Using your existing ball stud for comparison grind the bolt head down to match the ball on yours. likely better quality than the new studs that are available. Just thinking outside the box a bit. Again..

 

I Love outside the box thinking! I had never thought about that!

 

I take it the '71 bell housing is different than than earlier models. In this case, I would put the heli-coil in for the 1/2"
pivot ball for the extra strength and cut the threaded portion to the correct length.