1940 Indian 4 clutch adjustment

[Dave Bucco]

Just got done putting my clutch pedal/linkage etc. on my 1940 Indian 4 with a newly rebuilt powerplant and after noticing that the weight of the pedal itself pulls the clutch lever forward I remembered that when I took it apart, this was not the case, as there was some resistance to ANY movement in the linkage/lever (possibly some kind of internal spring?) before the beginning of clutch disengagement (freeplay). In other words there was SOME resistance in linkage before slack was taken up, then when clutch started to disengage, much more resistance was progressively felt as pressure plate was engaged. It had original clutch when disassembled. Very stiff! Now has new style clutch with half the number of springs. Not so stiff now. Can't remember being able to easily move disengagement lever on trans. housing back & forth before disassembly. With (or without) any linkage attached, lever now moves forward and backwards freely, about 3/16", with no resistance. Unlike the rear brake pedal, clutch pedal has no spring on pedal itself to hold it back against it's stop in rearward position, so the 3/16" (manual calls for 3/8") freeplay disappears, as the weight of the pedal moves the linkage/clutch lever forward, as described earlier. Unfortunately, I didn't realize the "sloppy" lever was a problem until I got as far as I did. I am certainly no expert on this machine, but this doesn't seem normal to me. Anybody got any ideas or suggestions as to what is causing this?

Thanks, Dave

[dane]

Should be no resistance as clutch lever is moved back and forth until throw out bearing is engaged. I added a return spring to my linkage to maintain free play while clutch is engaged to avoid premature wear of forks, throw out bearing.

[Dave Bucco]

Hello Dane. Thanks for your reply. I would certainly agree that it is undesired for any clutch disengagement system to be in contact with the throwout bearing, whether car, truck, or motorcycle. That being said, I am curious as to why the following paragraph appears in the (Indian) "Riders' Instruction Book", pages 13/14, under the heading Clutch Adjustments.

"The clutch should require no adjustment except lengthening or shortening of the throwout rod. Adjustment can be checked by PRESSING DOWN ON THE PEDAL UNTIL ALL SLACK IS TAKEN UP (emphasis mine). "This movement of the pedal should move the end of the lever (Fig. 8), 3/8 of an inch".

Given the previous statement, I can only assume that some tension (before finger mechanism engagement of throwout bearing) must have existed with the original clutch set up or it would not have been necessary to "press down on the pedal until all slack is taken up", and that Indian wasn't worried about this.

Here is where I am at now. Clutch pedal goes all the way down and hits frame lug for left front footboard mount. TOTAL clutch arm movement is 1/2". Subtracting the 3/16" freeplay movement this leaves 5/16" of clutch arm travel for disengagement of clutch. Will this be enough or should I reduce freeplay even further?

I am assuming aftermarket clutch is different from factory set up in dimension and/or function.

Also, clutch pedal hold down lever no longer functions properly due to the fact that there is not enough "pushback" tension through linkage assembly from 8 spring pressure plate assembly. This feature sure would be handy in an emergency situation. It functioned perfectly with the stock set up. Now it will not even dog in, let alone stay in when pushed against stop manually. Given that I won't be riding this machine tens of thousands of miles, I am now kind of wishing I'd have left the factory set up alone, the factory setup being hard on parts withstanding.

Any comments/suggestions always appreciated!

Dave

[PRG]

Howdy Dave,

Starting backwards on the linkage issue a fully functioning disengaged clutch should have the arm at roughly 6:00 o clock and engaged roughly at 5/8"s inch forward of that on the softest (most compressible) of the traditional aftermarket clutches available over the years, the Chalfant. The King and especially the sintered bronze Qua require slightly less disengagement range. 8 springs should still provide hefty resistance and your clutch stop functionality operating as normal. I would never use 16 again, in fact, would experiment with 6 if it wasn't such a hassle to change them (run 12 on a 348 and only 8 on my 346 with Qua's just to show you the latitude possible with Indian clutches). Your clutch arm should be free, no internal spring to rotate it forward and while using 1/2 the springs originally fitted would imply a lot less effort at the pedal it should still be substantial unless your plate stack height has been increased or an aftermarket spring of less rate fitted.

On the issue of your clutch fingers engaging the lip of the throw out bearing. The modern ones fitted are immensely robust and glide with little resistance. I have operated my 440 and (the late) 441 for over 20 years with no concern for the factory adjustment accept for noting the arm position in the engaged position (stack height). My entire focus is on achieving full clutch disengagment with minimal pedal travel relative to its position to the frame casting. For every additional bit of depth you press the pedal down after having achieved disengagment the more resistance through rising spring rate and the potential for the real possibility of damage, coil bind, increases. I have worked on machines where one clutch finger broke off and the other bent until it popped off the rim of the throw out bearing from the owner punching down the pedal too far. As I ride these in heavy city traffic where reflex action is critical without conscious thought, I use that frame casting as a mindless stop when using the clutch.

Many Four owners not familiar with this gearbox layout need to be reminded that there is no thing as a completely silent box. It's going to clunk going into first at rest and if one is not finessing it with rev matching also on downshifts.

[Dave Bucco]

Hi Peter.

Thanks for your thoughtful response. First off, I would like to state that I purchased this machine 25 years ago and have been working on it for about 15 years. It was an all original machine missing only the correct seat. speedometer, and center stand spring. I have never ridden this or any other four. I am here to learn from those of you with experience and it is never my intention to seem argumentative or condescending in any way. I would never want anyone to think "hey dude, if you know so much, why are you on this forum asking questions"? That being said, l can assure you with complete confidence that my clutch arm had some type of internal resistance to it BEFORE the finger mechanism contacted the throwout bearing. Since I have been advised a couple of times now that this is not the case, I consulted the Indian Motorcycle Parts Catalog 1940 Edition & this is what I found under the heading of clutch group, page #56: Factory No. 35B339 - Release Shaft Tension Spring. There is a picture of this spring on page #55 and also in the online greers catalog, right where I would guess it should be, on the Release Shaft. As I said earlier, I am here to learn so if there is something wrong with my interpretation of the catalogs, anyone please feel free to explain what is wrong with my logic here and in my previous posts, and I will gladly stand corrected. I can only assume that my clutch was reassembled without this tension spring, or it was done incorrectly, as my release arm moves back and forth freely. Maybe with the new clutch set up this was intentional on the builders part. I have no idea. I can only say that from a restoration standpoint, it is not desirable to put a return spring on my clutch pedal.

Well I had much more to ask you, and after having it deleted (twice now) while trying to post it (web site says I am not signed in when I am, then deletes text when I do log in-again!) I don't have another hour to retype. Maybe I just don't know how to use site properly, I am not very computer literate.

Any and all comments/suggestions appreciated!

Thanks, Dave #3695

[PRG]

Howdy Dave,

When typing long treatises (as I have had a bad habit of doing over the years...regular readers roll eyes in agreement) you need to select keep you signed in when logging on or it times you out. It has been years since I had to pull a release shaft but I believe that spring is located to the outboard side of your right clutch finger (when motor flipped to be worked on, otherwise left hand when viewed in frame) and is there to control end play of the finger and shaft assembly. To verify, grab your release arm and pull outward, it should pop back firmly against the face of the case. If the "case" it would more appropriately named a compression spring.

One thing I might add is that the release shaft runs in a rather tightly clearanced bore through the cases and as these motors ran very "dirty" back in the day, contaminated oil and any minute bit of rust on the shaft will cause is to bind or exhibit resistance in a motor having sat for long periods of time in unverifiable storage conditions.

http://www.patwilliamsracing.com/194...dianfour28.jpg

[Dave Bucco]

Hi Peter. First off, I STAND CORRECTED. After posting my last message the other eve I went downstairs, sat in the arm chair, and after a little more contemplation of the issue thought to myself, "boy am I going to feel stupid when Peter writes me back and tells me that spring is for end play". Further digging on the Greer site (looking at a drawing of the spring itself) confirmed that it could not function in the manner I described, no way, no how! The more I read your first response the more sense it makes to me . You would think after all these years I would learn not to take factory service/riders' manuals as absolute gospel. Sometimes it takes awhile for things to get through my thick head at times. You sound like you have a pretty extensive knowledge about these machines so don't be surprised if I want to pick your brain further sometime in the future.

Thanks for your patience (and putting up with me)!!!

Dave #3695

[PRG]

Howdy Dave,

With a demonstrated sense of mechanical empathy here already what with your concern for parasitic drag of your clutch pedal's weight bearing on your throw out bearing we can extend that awareness to instances where your intervention can really preserve this cherished machine in a measurable way, especially if not ridden frequently. Can't remember if my long storage cold start diatribe was posted here or at CAIMAG but in absence of finding that under search prelubing your motor before starting it can add immeasurably to its longevity. Both pumping oil into you mains/rods via the drillings behind the screws on the right side of your top case, but more importantly saturating the felts under your rocker covers.

As you probably observed when building your motor the most improbable format for lubing your intake valve train, four small ports within the exhaust valve lash adjustment compartments. Above, the only needle/roller bearings in this entire motor (unlike a Chief full of them in many applications) to be lubed by mist up the intake pushrods channels on this motor with no crankcase windage creating ability what with being vented unrestricted to atmosphere. Got to hand it to Indian engineers at the time desperate to battle the rising sunami of the ever improving Knucklehead with minimal financial resources. To step away from the atmospheric/exposed valve train era they enclosed the intakes without any positive pressure oil lubrication utilizing a principle dating a thousand years previous, fluid surface tension. Mist merely rising from your sump on a warm engine (emphasis in that) rises to your rocker felts, is absorbed, collects into droplets and then drips into those tiny cups with drillings into the needle bearings as well as onto the rocker pad and intake valve head.

Problem with that scenario in 2017, oil aeration is the enemy of catalytic converters and 4 wire o2 sensors. Motors are positive pressure lubed at critical points and car/oil mfr's want little flailing around in the crankcase afterward as evidenced by modern Porsches running as close to a vacuum as possible. Your best defense, run a multi like Valvoline VR1 15-50 with zinc (a Four the text book example of flat tappet motor with poor cam/tappet interface) and saturate your felts before starting so the lag before warm oil takes over does not cause excessive wear.