Canon 7D mark II main dial issue

Archibald wrote in post #18537825
I don't know anything about rubber on the main dial... but I do have a problem with the main dial of my 7D2. Like you experience, sometimes it takes more than one click to make a change to the aperture or shutter speed. I have about 40,000 clicks on mine. Maybe it needs cleaning.

I experience the same issue. About the same mileage on the body for me, too. No excessive heat and humidity in NorCal, to speak of a regular occurance.

I have been putting up with it for over a year, and I am curious as to what the fix might consist of. Not enough of a bother to send in the camera for a Canon fix.

Wilt wrote in post #18798533
I experience the same issue. About the same mileage on the body for me, too. No excessive heat and humidity in NorCal, to speak of a regular occurance.

I have been putting up with it for over a year, and I am curious as to what the fix might consist of. Not enough of a bother to send in the camera for a Canon fix.

I've had main dial issues on the 7D2 and 5D4. Both repairs resulted in an 'assembly replacement' and the cost wasn't so bad as far as camera repairs go. About 150$ or so.

Since this thread started I began to have the exact same symptoms. The problem was easily diagnosed as the slippage of the rubber on the main dial. I tried glue and other approaches but nothing worked to my satisfaction. I took it in to a Canon. (I'm only 20 minutes away from the New Jersey facility). The solution was simple, but expensive. It literally required the complete replacement of the top of the camera, which cost me between $100 and $200 dollars.

I had the rubber slippage issue on the 40d, years ago; used the glue trick w/ a toothpick. It was very clear it was slipping, though, in that when I dialed the wheel very slowly it would click and adjust; but, if I ‘spun’ the wheel as you do when making rapid adjustments, it would sort if glide/catch.

If in these cases, the wheel clicks no matter the speed used to spin it, I would suspect another fix is in order.

Thank you for the insight into past repair !

I haven't done anything about my problem. Wheel does click when I rotate so I wasn't convinced it was the rubber slipping. Since it works 85% of the time I just let it be. My 5d4 has been fine though.

I have this with a 7D2 that I borrowed, on the front dial. It seems to be the same notch in the action that is dead, because I can go forward, say, three clicks and the shutter increments every time, and then it takes two clicks for the next increment, two clicks to go back one and then one click, etc. I could probably mark the wheel and see that it's always the same position or positions. I'm considering buying it, and if it's not going to get worse I will probably just live with it for now. My assumption was that it was a rotary encoder, but maybe it is old-fashioned contacts in there.

Looking around, the front wheel assembly seems to be available as part CG2-4396-000 according to this AliExpress listing. Pretty cheap. $30-ish.

Complete top covers (which sometimes include the wheel) are available for $100~200 range, new and used.

Lately, my 7DMkII is also exhibiting the wheel problem.

Response can sometimes be very erratic in that it will completely skip two or three choices with a single click and maybe the next time change nothing at all with several clicks.

It also will "switch directions" as in I roll to advance the shutter speed, it may climb for two clicks and then go backwards for the next three.

For instance, I may be at 1/1250 and want to advance to the next stop; it may work perfectly; or, it may jump to 1/3200 with a single click; and, the next click take it back to 1/640.

It is definitely clicking and I feel every detent.

Sometimes, it will work perfect for long enough that I forget it has the problem.

It has been being about a million degrees and heinously humid and the problem seems to manifest itself more under those conditions.

If I am careful to keep quite a bit of sideways/forward and downward pressure on the wheel, it will advance and retreat one stop for every click like it is supposed to, with none of that skipping around.

The outer rubber-like surface has notches that may very well be the detents that we feel and may have nothing to do with changing the settings as the wheel is turned.

What I think is happening is the outer rubber is not gripping the slick inner wheel and thus not holding it when it is turned, thus the inner wheel that actually controls the camera can slip and spin in either direction.

I am thinking of making an attempt at lifting the outer rubber and cleaning between it and the inner wheel with rubbing alcohol which seems to be the medicine of choice.

However, they don't make this easy on the 7DMkII.

The wheel on the 7DMkII is quite a bit smaller than that on the 7D and does not protrude above the housing nearly so much.

I can easily roll the outer rubber of the 7D sideways and actually see the groove in the inner wheel; not so with the 7DMkII; and, I am afraid that if I lift the outer ring enough to get between the two, it may break and then there I would be.


Another thing I have noticed while I was playing around is that the 7D has a much more positive action; as deaf as I am, I can actually easily hear the detents as I roll the wheel on the 7D; it sounds like spinning the cylinder on Matt Dillons .45; not so with the 7DMkII, I barely feel the detents and can't hear a thing.


UPDATE: the next morning: The outer surface of the wheel is definitely a band of rubber-like material.

With my strongest reading glasses and a strong head-light, I was able to use a sharp dentist's pick and BARELY lift the rubber the tiniest bit; not so much lifting it away, but more or less rolling it to one side.

I tore the house, barns, and several trucks apart and could not come up with a syringe that still had a needle --- so scratch that idea.

What I was able to do was I dipped a Q-Tip in alcohol and pressed it against the dentist's probe and let the alcohol run down the probe and into the joint between the outer and inner surfaces.

I would do this and then advance the wheel a couple notches and repeat, until I had worked my way all around.

I could wiggle the outer ring and see the alcohol squishing between the two layers.

Once I got a good dose of alcohol all around, I rolled the wheel back and forth in both directions several times.

I did not turn on the camera for quite some time to allow the alcohol to dry.

After a good wait, I switched on the camera to see if I helped anything; alas, things were no better than before.


Next plan is to try some dabs of adhesive and see how well that works.

Unlike the older cameras, applying glue in the tight confines of the 7DMkII is not going to be no picnic.


I will say this --- my first thoughts were that no way could my problem be the rubber ring slipping; but, the more I fool with it, the more convinced I am that the loose rubber wheel is definitely the culprit.

There is a video on YouTube where a guy uses a 3D printer to make a replacement plastic replacement for the rubber ring; it shows him tearing into the camera and installing the replacement; however, he is working on a 6DMkII I believe it is; the process is probably pretty much the same.

BuckSkin wrote in post #19420125
Lately, my 7DMkII is also exhibiting the wheel problem.

Response can sometimes be very erratic in that it will completely skip two or three choices with a single click and maybe the next time change nothing at all with several clicks.

It also will "switch directions" as in I roll to advance the shutter speed, it may climb for two clicks and then go backwards for the next three.

For instance, I may be at 1/1250 and want to advance to the next stop; it may work perfectly; or, it may jump to 1/3200 with a single click; and, the next click take it back to 1/640.

It is definitely clicking and I feel every detent.

Sometimes, it will work perfect for long enough that I forget it has the problem.

It has been being about a million degrees and heinously humid and the problem seems to manifest itself more under those conditions.

If I am careful to keep quite a bit of sideways/forward and downward pressure on the wheel, it will advance and retreat one stop for every click like it is supposed to, with none of that skipping around.

The outer rubber-like surface has notches that may very well be the detents that we feel and may have nothing to do with changing the settings as the wheel is turned.

What I think is happening is the outer rubber is not gripping the slick inner wheel and thus not holding it when it is turned, thus the inner wheel that actually controls the camera can slip and spin in either direction.

I am thinking of making an attempt at lifting the outer rubber and cleaning between it and the inner wheel with rubbing alcohol which seems to be the medicine of choice.

However, they don't make this easy on the 7DMkII.

The wheel on the 7DMkII is quite a bit smaller than that on the 7D and does not protrude above the housing nearly so much.

I can easily roll the outer rubber of the 7D sideways and actually see the groove in the inner wheel; not so with the 7DMkII; and, I am afraid that if I lift the outer ring enough to get between the two, it may break and then there I would be.


Another thing I have noticed while I was playing around is that the 7D has a much more positive action; as deaf as I am, I can actually easily hear the detents as I roll the wheel on the 7D; it sounds like spinning the cylinder on Matt Dillons .45; not so with the 7DMkII, I barely feel the detents and can't hear a thing.


UPDATE: the next morning: The outer surface of the wheel is definitely a band of rubber-like material.

With my strongest reading glasses and a strong head-light, I was able to use a sharp dentist's pick and BARELY lift the rubber the tiniest bit; not so much lifting it away, but more or less rolling it to one side.

I tore the house, barns, and several trucks apart and could not come up with a syringe that still had a needle --- so scratch that idea.

What I was able to do was I dipped a Q-Tip in alcohol and pressed it against the dentist's probe and let the alcohol run down the probe and into the joint between the outer and inner surfaces.

I would do this and then advance the wheel a couple notches and repeat, until I had worked my way all around.

I could wiggle the outer ring and see the alcohol squishing between the two layers.

Once I got a good dose of alcohol all around, I rolled the wheel back and forth in both directions several times.

I did not turn on the camera for quite some time to allow the alcohol to dry.

After a good wait, I switched on the camera to see if I helped anything; alas, things were no better than before.


Next plan is to try some dabs of adhesive and see how well that works.

Unlike the older cameras, applying glue in the tight confines of the 7DMkII is not going to be no picnic.


I will say this --- my first thoughts were that no way could my problem be the rubber ring slipping; but, the more I fool with it, the more convinced I am that the loose rubber wheel is definitely the culprit.

There is a video on YouTube where a guy uses a 3D printer to make a replacement plastic replacement for the rubber ring; it shows him tearing into the camera and installing the replacement; however, he is working on a 6DMkII I believe it is; the process is probably pretty much the same.

I would be veeery careful applying any glue in there. The slightest mistake will be a costly one.

mwsilver wrote in post #19420760
I would be veeery careful applying any glue in there. The slightest mistake will be a costly one.

Thanks; I am an extremely careful man by nature.

This separate rubber band business is purely planned obsolescence.

Our old Rebel T3 -- we have two of them -- have way more usage on them than our 7Ds and 7DMkII, and they will never have this slipping rubber business as their wheels are solid plastic with big deep notches.

If Canon was going to use the rubber band, they should have provided simple easy access to replacing it, which could easily have been accomplished.

An accessible removable axis could easily have been employed such that you unscrew it out the front or back, drop out the wheel, either replace the rubber or the whole wheel --- or just add some glue -- drop the wheel back in and replace the long screw.


If I had been forewarned of this weakness, I could have put it way farther down the road by simply using the Quick Control 98% of the time and save using the wheel only for those times when speed is of the essence.


Looking at a repair from another angle --- if I could find a substance that would shrink the rubber without destroying it, that might be a route worth considering.

I have also considered trying belt dressing, but I need to investigate just how runny and how permanent the bond before I dribble it in there.

Pine Rosin is another possibility.

Based on your description I think it's pretty unlikely that the rubber is slipping. If you feel the detent action, then in all likelihood the inner wheel is turning because I think that's where the detent mechanism acts.

I assume there is an encoder wheel in there, and in my case some of the encoder positions are not being read. Your issue may be a cracked ribbon cable, where one of the signals bounces or cuts out.

This is what the wheel assembly looks like, although the pics are far from good: https://nl.aliexpress.​com/item/2251832708497​536.html