Hot Rods Mopar Clutch Pedal Linkage Modification

I’m primarily a Mopar guy but I’m wondering if the annoying issue I’ve run into is present in other brands or just a dumb Mopar thing.

The pic I attached is a generic Mopar clutch pedal pushrod which has large irregular shaped holes at each end that slip over the round pivots on the pedal and torque shaft (Z bar). I have no idea why the engineers made the holes like this but where it attaches to the clutch pedal, there’s an odd angle as it passes downward through the firewall and this odd angle creates a weird clunking sound every time you depress the pedal and it rotates on the pivot. I can stick my head under there and actually see the push rod slop around and clunk as the pedal moves downward.

Do other makes have this idiotic design? It’s driving me crazy and all the Mopar guys say it’s normal.

I’m considering a modification. Like maybe weld the hole up and drill it only large enough to slide over the pivot. Any thoughts on this idea?

 

Just a guess, but maybe there should be a bushing in those holes to take up the slack?

 

Exactly my thought. HAHA I'd first grab some duct tape. HAHAheha
Mopar guys are reaching for the aspirin

 

If I remember correctly the spring keeps the elongated hole taught against the pivots. There were horse shoe shaped clips that went over the pivots. The plastic bushings worn or lacking grease inside the z bar ?

 

According to the service manual, no bushings.

 

There are horseshoe clips that hold everything tight. I guess I could put in a new clip and see if that keeps it from shifting around but it still seems like a dumb design to me. No plastic bushings where the rod connects to the pivot.

There are plastic bushings inside the z bar but everything is new and freshly greased. The clunking sound is only coming from the pivot on the clutch pedal and I think it happens because the odd angle the rod moves at. The pressure on the rod isn’t consistent in one spot. It rotates over 45 degrees on the pivot and this causes the rod to shift a couple millimeters under pressure and clunk as it repositions itself.

 

I usually cut the ends off clutch rods like that and replace them with some nice rod ends.

 

If all of the anti rattle springs are on there,,,it won’t clunk !
The springs are there to make sure all the slack or clearance is out of the linkage .
Is this for an E-Body ?

Tommy

 

Heim joints and a rod threaded on each end would look trick and not slop around...
6sally6

 

In order to use heim ends,,,,all the brackets would need to be modified .
The Z bar and the under dash pedal attachment point all have male studs that receive the rods .

Tommy

 

I’ve had half a dozen 4 speed Darts and Barracuda’s, and never had that problem. 340’s and 383’s.My Formula S Convertible 383 4 speed is apart for resto. I’ll see if I can find the linkage tomorrow? I think the above post about the springs is correct, and I seem to remember white plastic bushings that go in those holes. Mine were all A bodies.

 

Mine is an E body,,,,,,no problems after I did the stuff like the factory did .
I had several pieces missing to begin with,,,then I figured my problem .

Tommy

 

No bushings, that’s how they are, I just put together an early Barracuda with a four speed and no clunk at all

 

Yes,,,,,no bushings on the rods,,,just these clips .

Tommy

 

Yes

 

The 8 & 6 cylinder clutch pedal AND cross shaft (z-bar) are different in the same body line (A-B or E). This can on occasion cause alignment and or pedal ratio issues when mis-matched.

 

Okay,,,I figured it was from your avatar .
It’s okay to discuss certain things here,,,,,but don’t post any pics of machines after the cutoff year,,,,1965 .

Tommy

 

If all your linkage is together as the factory sent it out the door -another possibility is the trans mount rubber bushing has moved off center of the sleeve it rests on. This will cause things to be catawampus and linkage misalignment.

 

There are no wear surfaces built into any the factory stuff, the clutch rod will just dig into the pins on the "z" bar and the clutch pedal pivot . You can either replace what was there originally and let it last another 30 years or build it so it will outlive your grandchildren , either way....

 

Keeping in mind there's no good reason to make it outlive your grandchildren!

 

My old Power Wagon had the very same , Rod between pedal and Z bar . I removed both , remove the pins , drilled the bar and pedal . Went to a local spring shop and purchased a piece of 3/8 UBolt stock ( straight before bent ) correct length , 2 Heim joints ( greasable ) , made up the new rod the correct length and bolted it together . Just be sure to use a large enough washer , if the joint were to fail the rod will not come off and be lost or clutch not work .

 

I like to make things 'bulletproof" rather than relying on stupid pins , clips and nonsense from days gone bye or some snap together bullshit like a new car.

 

Thise stuff wasn't meant to last or be durable, it was meant to be assembled quickly on an assembly line and shoved out the door, and sold to john Q public. We're just stewards of the past.

 

Brewers Performance could probably help you out. They are the Mopar 833 4 speed people.

 

I don't know about the later models, but on 60s Mopars it wasn't uncommon for the firewall to flex from stress applied by the clutch pedal support. This could cause some misalignment that might magnify some of the problems you're having. And on the z-arm inspect the welds where the pedal and fork arms attach to the cross shaft for cracks. Sometimes you'll see rust stains around the welds if the paint on the z-arm is still intact. Either of the problems is more likely to occur on higher mileage vehicles or when a stiffer pressure plate is installed.

 

I've had Mopars with 4-speeds for over 50 years and never had that problem. The clips should keep them from making noise. Are your clips in good shape?