HARD CLUTCH PEDAL CURE
by Rich Motts, (Rrich)


Article is based on a 1969 Commando 225 V6, T-14 3 speed, stock aluminum
bell housing, stock direct clutch cable type linkage.


Here's what the problem was:

Clutch pedal was very hard to push. So hard it actually broke the floor on 4 different occasions where the cable comes up through. After really strengthening the spot around the cable, I noticed the floor around the seat mounts was beginning to crack from pushing the pedal down so hard. It also seemed like there never was quite enough pedal travel to have free-play at the top and still release. 

Several Jeep shops and 2 dealers said that was normal for a Commando, they are normally very hard to push and commonly break the fork and the cable pulls through the floor. "Live with it" they said, "If it pushed easy, we'd have to fix it."  There's even a hard to find kit to strengthen the floor and firewall to "cure" the problem. A friend that used to service a fleet of Commandos said he's familiar with the problem. He said sometimes you get "lucky," the clutch works OK for about 15,000 miles before it really gives trouble again. He said it was just a characteristic of Jeepsters. He said he used to weld a gusset on the fork to keep it from breaking, even then, it would still break the gusset. I found it difficult to believe that it can't be cured properly. 

 

Putting on a new custom made cable with almost no resistance didn't help much. Finally it got to where it wouldn't release enough to shift properly, tear down time.

The cause: Wrong parts combination, mainly the throw out bearing and the angle of the fork in combination with the pressure plate "cover." The angle of attack is wrong and the bearing binds on the fork, causing the effort to actually bend the fork to get enough throw. 

It's perpetuated by parts books calling for the wrong parts combination. I actually tried 6 different suppliers, including Car Quest, all gave me different clutch sets, none were correct. Original equipment calls for a diaphragm type clutch rather than the 3 finger Borg and Beck type, so I stayed with that type. 

The mechanical advantage is reduced when the angle of the fork is wrong.

The cure: Use the right combination of parts, get the correct angle on the fork and the clutch pedal
effort becomes feather light and works like a dream. 

1. Place the clutch cover face down on a flat surface (out of the vehicle.) Through the center hole measure the height of the fingers from the flat surface. The "problem child" I had on mine was only 2". Every parts book called out for different covers ranging from 2" to 2 5/16, except one, Center force, it was about 2.5". Each little bit of height gets the fork closer to the right angle. It's only a small amount, but it makes a huge difference.

2. The throw out bearing all the parts books call for is not the correct one, it's too short by about 1/4". All the books I encountered called for the short one (N1178) that will bind against the fork. The correct one (longer one) carries the number N1086SA, it's a standard Chevy truck bearing. It's only a 1/4" difference, but it makes a world of difference.

3. The pivot ball the fork rides on should be replaced with a slightly longer one as well. This gets the fork angle in the right position for best mechanical advantage. There are only 2 that fit the bell housing, use the longer one. Again, the tiny 3/32" change makes a huge difference.

The fork may or may not bind when new as long as 2 out of the three items I mentioned are used, but as the clutch disc wears, it looks like it will bind soon. Using all three fixes looks like it won't bind, but time will tell.

Here are the parts numbers that worked for mine. Center Force is a well known quality manufacturer of clutches. They make several different hi-performance systems, I chose their "standard" Gold one. It still exceeds stock holding power by about 30%, so it's not a cheesy one.

Center force "cover" # 361662 $128.98
Center force disc # 383271 $60.92
Pilot bushing # 3752487 $2.36
Throw out bearing # N1086SA (standard Chevy truck) 
$27.90
Pivot ball (long) Link # 15592268 $11.52
Clutch fork # 1378486 $58

The first 3 items were obtained from 4West Four
Wheel Drive in Colton, CA, 
(909) 824-0024 or (800) 85-4WEST www.4West.com 
Very knowledgeable and helpful people. It's not just a chrome and bolt on "pink stuff" shop.

The next 2 items were from Clutch Masters in Rialto, CA 
(909) 877-6800 www.clutchmasters.com
This is a huge place that only does clutches and related parts, including flywheels, starter ring gears, and custom systems. They manufacture and rebuild on the premises. Again, experts.

The last one was from Harvey's Complete Jeep shop in Long Beach, but most everyone has this item, it's standard on Jeepsters and CJ's..

Most any good parts supplier should have or be able to get the parts, they are not unusual. The ball pivot
would be the hardest to find, but it's late model GM.

When I took mine apart I found it had the wrong clutch cover (but I didn't know it was wrong then,) but the right T/O bearing (the long one,) and the short pivot (I think it's original?) The fork and T/O bearing were broken. The fork had been binding on the throw-out bearing. As the clutch wore it got worse.  I'm sure when it was last replaced it was working OK, but as time went on it got worse.

I'd tried ordering the right parts from several different "professional" suppliers, almost all of them had a different part and none of them gave the right angles.. It was very obvious all the replacement covers and combinations I tried would not cure the problem, it would happen again soon.

Even when I tried to use the taller Center Force cover with the recommended T/O bearing the problem still existed, it bound up same as before. I tried it with a new long bearing - it helped but was still not right, it looked like it bound slightly and as the disk wore it would get worse. Then I put in the longer ball pivot too, that last little bit really made the difference. 
The angle was finally right and everything cleared nicely. So actually it was a cumulative cure. It moved the inner end of the fork back almost 1/2" on the cover, 1/4 inch on the T/O, and 3/16" on the pivot.  It put the angle of the fork in the right position for best mechanical advantage and prevented it from binding.

When I first pushed down on the pedal after installing the right combination I thought I must have left something loose, it was so easy I didn't believe it. It works like a charm. Free-play at the top like it's supposed to have, with full release just part way down. It no longer requires 3 men and a boy to operate it. It's so light a touch it's almost scary,
but I know the Center Force pressure plate is doing it's job correctly.

The only problem now is when my girlfriend finds out how easy it is, she'll want to drive it.


Back To AJC's Technical Directory

HOME