Clutch Adjustment

[SNOWBIRD]

Old school. to make a bushing fit more snugly in the housing, simply dimple the bushing with a pointed chisel before you tap it into the mount.

 

[okey0]

What's makes this adjustment a bit hard on an Amphicar is the slop in the clutch cable system. The way I do it is to go at it with the rear seat out, hook my left hand middle finger over the clutch fork arm and pull it until it stops hard. Use my right hand to pull the slop out of the clutch cable by pulling towards the back of the car at the threaded gizmo at the end of the cable and holding that position by the thumb and index finger of my left hand. Now, using my right hand again I adjust the special clutch cable nut until all the slack is gone. I then back it out a turn or two so that the fork arm has about 1/16 inch of free play. The whole idea of this type of clutch adjustment is that the release bearing is lifted away from the clutch disk when your foot is off the pedal. What lifts it away is that light spring tension you noticed when pulling on the clutch fork. Too little free play and the release bearing will constantly drag on the clutch and they just aren't designed for that and will fail. Too much and the release point of the clutch will have the pedal too far down near the floor.

i followed your adjustment method (copied below) but did it while the engine was running. i pulled back on the clutch fork arm until i could feel and hear a little drag going on, then backed off until that sound/feel went away. That is the point that i adjusted the cable nut to. Does that sound like it would work?

 

[LSolheim]

i followed your adjustment method (copied below) but did it while the engine was running. i pulled back on the clutch fork arm until i could feel and hear a little drag going on, then backed off until that sound/feel went away. That is the point that i adjusted the cable nut to. Does that sound like it would work?

Sounds OK - as JF noted, the whole object is to reduce cable slack without putting any constant load onto the throw-out bearing. Due to system/mechanism slop it will give you 3/4 - 1" play at the clutch.pedal.

 

[jfriese]

That might work okay but I would think that by the time the engine slows down a bit you are more than just touching the clutch disc fingers. I'm going to suggest sticking to my system as in the manual. It is tried and true for 15 years now. You really don't want the throw out bearing dragging on the clutch fingers, unless you like pulling the engine to change the release bearing periodically. I've pulled engines many times and don't find it that much fun. I always error on the safe side when it comes to clutch adjustment.

John Friese ( Creator of the High Performance Clutch System )
67 White
67 Red

 

[Cap'n John]

I always adjust the clutch with the engine at rest and cool. Make sure the cable is moving smoothly, w/o binding. Reach back and pull the arm forward until it just stops (but no pressure), Tighten the ball-nut until I have 1/16" play, hold it with one wrench and tighten the jam nut in place with a 2nd wrench, recheck play, then I'm done. Never had any problem, nor slippage. This takes into account stretch during use giving the correct amount of pedal during use.

 

[SNOWBIRD]

Something that has never com,e up here.
I have come across this on two Amphicars now that have been poorly worked on in the past.
first hint to this problem is much effort is needed to push clutch in and second is there is not enough cable movement.
Answer.... The three hole triangle pivot(42-21) at the front ,under the gas pedal floor board is on backwards. the holes are in different positions. Tough job to change, need a small mirror to see it.

 

[jfriese]

Correct cable movement is about 3/4 inch for full pedal throw.

John Friese
67 White
67 Red