Clutch push rod and adjuster screw tearing each other up

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Faustmill
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Clutch push rod and adjuster screw tearing each other up

#1

Post by Faustmill »

65 FLH with 5 finger clutch. The clutch push rod and adjuster screw grind on each other, resulting in a bigger gap between them, causing severe clutch dragging. I think this mostly happens with the bike in gear, stopped, and the clutch disengaged (i.e, clutch hand lever squeezed in). I have replaced the push rod bearing with the "old style" bearing in the kick start cover twice (two different bearings, thinking the first one was bad) and again a third time with the "new style" pancake bearing that goes between two thrust washers. Bike can't get more than 10 miles without grinding up the push rod and adjusting screw to the point where the clutch is dragging badly and sometimes the mousetrap will not return over top dead center to its locked position. I have had this apart several times, including once with an experienced HD mechanic. The push rod bearing looks OK, the rod turns freely in the mainshaft, and the threads in the releasing disc for the adjusting screw are solid in the releasing disc (i.e., the adjusting screw, the adjusting screw locknut, and the releasing disc all stay locked together). What am I missing? Thank you.
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Re: Clutch push rod and adjuster screw tearing each other up

#2

Post by steve_wood »

Primary chain too tight?
Bosheff
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Re: Clutch push rod and adjuster screw tearing each other up

#3

Post by Bosheff »

There should be a gap between the pushrod and adjuster screw with the clutch engaged. The only time they should touch each other is when the clutch is disengaged. I generally adjust the screw to where I want it, and back it off an 1/8th of a turn....bosheff
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Re: Clutch push rod and adjuster screw tearing each other up

#4

Post by steve_wood »

Bosheff:

So if there is a little free play in the clutch linkage rod (between the mouse trap and the clutch lever arm), does that produce a gap between the adjuster and the push rod? It should shouldn't it?

steve
Faustmill
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Re: Clutch push rod and adjuster screw tearing each other up

#5

Post by Faustmill »

Bosheff: I always adjust the screw as you said -- bottom it out on the pushrod and back off about 1/8 turn so there is a small gap between them. I think the damage is happening when the clutch is disengaged, the bike in gear, and stopped (like just before a light changes green or sitting in gear at an intersection waiting for traffic to clear so you can take off). At that time the pushrod is really pushing hard on the adjustment screw in order to overcome the pressure of the clutch springs and disengage the clutch.
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Re: Clutch push rod and adjuster screw tearing each other up

#6

Post by jdpan »

The correct clutch rod measures 13 9/16" I believe, might wanna check it.
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Re: Clutch push rod and adjuster screw tearing each other up

#7

Post by Faustmill »

jdpan: I have replaced the push rod twice: Once with a new "old style" bearing and again when I installed the pancake "new style" bearing. The clutch appears to be working fine before I put the primary cover back on -- pull in the clutch hand lever, the clutch releases, and you can rotate the releasing disc and the fiber discs by hand. Also, for the first 10 miles or so after reassembly, the clutch works great with very smooth shifting.
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Re: Clutch push rod and adjuster screw tearing each other up

#8

Post by RUBONE »

There are only a couple of scenarios that can produce what you describe. The rod binding in the mainshaft, or the throwout bearing not working properly. When the clutch is disengaged the pressure plate, pushrod and center of the throwout bearing are essentially one piece rotating at the same speed. The only way the rod can turn against the adjuster screw is if it slows down for some reason, such as the throwout bearing not acting as a thrust bearing, or extreme friction within the shaft. That could be the clutch springs coilbinding due to incorrect adjustment and preventing the rod from having full pressure on it therefore allowing slip between it and the screw end, the smallest friction area so first to break free.
In order for the rod to bind in the mainshaft, one or the other (or both) would be bent, or the clutch somehow shift to one side when disengaged and allow the rod to bind up, not very likely.
Good luck
Robbie
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Re: Clutch push rod and adjuster screw tearing each other up

#9

Post by jdpan »

Without being able to put an eyeball on what you have, it's difficult to speculate. Pull the primary and fire it up, keep an eye on the adjuster nut, mabe it'll reveal its retardness. >>>If you have the correct parts and it's adjusted per the manual,<<< it should work. It sounds like there's an issue with the throw out bearing even though you've replaced it already. Possibly heating up changing its dynamics. That would explain the ten mile waiting period.. Maybe.
Faustmill
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Re: Clutch push rod and adjuster screw tearing each other up

#10

Post by Faustmill »

RUBONE: "There are only a couple of scenarios that can produce what you describe. The rod binding in the mainshaft, or the throwout bearing not working properly."

This is the third throwout bearing I have installed and the same problem persists -- the new bearings seem to make no difference. Since I have done this job about 6 times, including twice with a HD shop owner/mechanic who has worked on HDs for 40+ years, I am thinking something is binding in the mainshaft for some strange reason. The mainshaft is about the only thing left, since I have replaced and/or adjusted everything else I can think of. The rod is straight. If the mainshaft is bent, we are talking tranny rebuild both to find out if it is bent, and to replace it -- right? Thanks.

PS: Would a cracked transmission case or loose transmission mount cause this, even if the mainshaft is straight?
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Re: Clutch push rod and adjuster screw tearing each other up

#11

Post by jdpan »

If the mainshaft is bent to the point to where its binding the pushrod, you should be able to feel the friction of the rod meeting the mainshaft when you spin it by hand. If thats the case then yup, time for a new mainshaft. I'd think you would have felt it in the ride if its bent so severely in the form of a vibration..
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Re: Clutch push rod and adjuster screw tearing each other up

#12

Post by fourthgear »

The two types of throw out bearings take different type arms to activate them, & push rods , I believe , also.
There are three different clutch push rods for the four speed tranny & you can't mix them up .

41 -64 use one size & 65-69 have one & then 1970 up with the 1975 (I believe ) is when they went to the new type of throw out bearing & I don't believe you can mix the parts up .

One would think the clutch push rod spins the whole time the main shaft does. Thats what the throw out bearing is for.

Sounds like too much pressure on it or wrong parts.
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Re: Clutch push rod and adjuster screw tearing each other up

#13

Post by 58flh »

Sounds like -Bosheff & Rubone pretty much answered your? But 1 thing that is eating at me as im thinking bout-it, You had mentioned 5 spring set-up! Check your springs for binding/discolor from to much heat, & check your steel plates to for straightness, bluing or any thing that dont look right! also measure your pushrod ,be sure its for your set-up. Not that long ago, we put the ol-3-spring set-up on a electraglide with a stock H.D. clutch&plates, & all appropriate parts! The bikes running fine, the cust. had worries about clutch-slipping on a hill with 2 heavy people on it- After the original adj. 1st. time-- he has no problems!--/ check your primary-chain-- might need a new one? You are facing a easy-fix gremlin I call them! Once you pinpoint it ,its like that caused all this. Im sure you have been there before!!! ( Good-Luck )--- the guys on this site seen it all, fixed it all ,you will be back-up in no time! 58flh :mrgreen:
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Re: Clutch push rod and adjuster screw tearing each other up

#14

Post by Kuda »

Just a dumb question, but do you still have the oil scraper/dripper in the kicker cover? If you lost/broke it and your oil is low, the throwout bearing is running bone dry...

-Kuda
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Re: Clutch push rod and adjuster screw tearing each other up

#15

Post by Bosheff »

I've dealt with trannies with bent mainshafts, but this was not a symptom that was present in any of them. A bent mainshaft or bent pushrod will eventually wear on the bushings in the ends of the mainshaft if left unattended long enough. Usually this same problem will leave severe wear indications on the pushrod given enough time and/or miles. To check for bent mainshaft, do a runout check with a dial indicator. Bent mainshafts are hard on primary chains, but even harder on belts as belts don't seem to be as forgiving when over tightened....bosheff
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