Leica M4-2 Slow Speeds Total Failure?

[ulrich.von.lich]

I recently bought an M4-2 to temporarily replace my two M2s, both gone for service.

Although I was told the M4-2 was more problematic, I thought I might give it a try, since it's quite handy to have a hotshoe.

I notice the slow speeds are off. It would be ok if they can be adjusted, but now I'm having doubts.

Usually when slow speeds are off, all speeds between 1s and 1/30s would be off. However, on this M4-2, the 1s, 1/8s, 1/30s sound correct whilst the 1/2s and 1/4s are too fast, and the 1/15s is WAY too slow. Actually the 1/15s sounds like 1/2s.

I remember having heard somewhere the slow speeds on some M4-2s could never be adjusted correctly, and I'm starting to think perhaps it's a problem that a simple lubrification won't resolve.

I happen to have an M2 for parts. Does anyone know if the slow speed escapement assembly of the M2 is interchangeable with that of the M4-2?

 

[Steve M.]

Maybe I am just dense (and sorry, I don't know the answer to your shutter escapement question), but if you have TWO cameras that you sent out to be serviced and bought another one just to tide you over until they returned, why would you want to tear into the replacement camera? Why not just use the M4-2 as it is until the M2s come back? Most people seldom use the speeds you mentioned anyway. If I had a camera that only went from 1/30 to 1/500 it would be able to take any photo that I might encounter except in very low light.

 

[a.noctilux]

😕 I don't understand why you have "service time" your two M2 same time.

Maybe, your "new M4-2" needs service also, if that "slow-speed trouble" bother you.
😉
Just go to Photo Suffren to take some good advices.
They are helpful...

 

[ulrich.von.lich]

No problem Steve. The questions you raised are legitimate.

Over the years I taught myself some basic things in camera repairing. Many things are actually so simple, but I see most people prefer not to try. I did so because I felt obliged. I think a camera to a photographer is like a gun to a soldier, and a soldier should know something about his weapon, in case it breaks. I'm not trying to become a repair person, but I feel more comfortable with my cameras and lenses once I know them better, just like I feel more comfortable with the films I can develop myself. By the way, I learnt some first aid skills, too, and I don't want to become a doctor.

It's not only for the pecuniary reason. For example, once I brought a lens affected by fungus to a repair person in Paris. Although he was nearby, it took him quite a long time to return it to me, due to the high demand for his services. It was the only fast telephoto lens I had, and I missed the opportunity to photograph two concerts. When I finally got the lens, the fungus was gone but the helicoid wasn't correctly assemblated. Although it's a small mistake, I had to go back again. It was quite a hassle. And I saw a few more cleaning marks on some interior lens elements, too.

Today I can clean and lubrificate this lens myself. It takes me no more than five minutes to take it apart, with proper tools. I can clean the fungus as soon as I see any sign of it, so it won't grow while the lens is waiting to be serviced (I had waited two months). I also have several high quality greases which provide different feels, and I apply them accordingly. Also, when I clean my own lenses, I won't leave any mark on it : it's my own equipment to which I pay extra attention, and I don't have to rush the job.

It's more complicated with the camera body, especially with the rangefinder assembly. I'm not a reckless person, and I will only do what I can do. That's why my two M2s are gone for service. However, I can clean and lubricate the slow speed escapement assembly. It's a fairly simple task that I have done many times before, on my M2s, with success. However, I'm suspecting the assembly requires more than just oil. Hence my question.

Unlike you, I do use slow speeds. As a matter of fact, with a 50mm, I can handheld and get sharp images at 1/8s, and I use 1/15s a lot. I mean A LOT.

 

[a.noctilux]

Some years ago, I had bought second hand M6 Classic 0.85.
When using it the slow speeds from 1/15 s to 1s "off" or "not reliable".
It needed replacement of the entire slow speed module, not repairable or adjustable (many wearing parts of use ) .
Very expensive experience but would be good for ten years or more.

 

[ulrich.von.lich]

Like the professional lab Central Dupon Images in the 18th arrondissement whose employees scratched my negatives once and didn't want to apologise properly, Photo Suffren has disappointed me before and I will not use them under any circumstance. It's a bit ironic because I don't mind giving my cameras to Gérard Métrot who used to work at Photo Suffren, because he is a funny fella to talk to.

I sent both of my M2s for service because I need to get them back before a certain date, thus I prefer to do it as soon as possible. Who knows how long the repairs will last. I do have other cameras to use in the meantime. Let's just say I bought it because I wanted to have one more camera...

I happen to have one slow speed module of the M2, I called it the slow speed escapement assembly, which lays beneath the rangefinder. If it's the same as the one on the M2, I can simply swap them.

 

[a.noctilux]

Gérard owned Photo Suffren.
I know him as one of the nicest Leica Doctor since his Atelier 102.

Also I understand that he stopped his repair activity.
Nice people like Gérard become rare :bang: .

Have fun with your module swap.

 

[giganova]

The solution is easy: you need to drop everything right now, take an Uber to the nearest Leica store and buy an M-A.

 

[ulrich.von.lich]

Why would I take an Uber if I had the money to buy an M-A?

It's like eating spaghetti in a can and drinking an expensive bottle of wine.

 

[Roger Hicks]

Why would I take an Uber if I had the money to buy an M-A?

It's like eating spaghetti in a can and drinking an expensive bottle of wine.

What's wrong with the expensive wine? It'll make you feel better about the canned spaghetti. Either drink the lot yourself or share it with your lover and go to bed immediately. Either way, the spaghetti can be good...

Seriously, I'm surprised at a.noctilux's post. It's a fairly simple gear train. Who the hell wears one out?

Cheers,

R.

 

[Mark Wood]

This sounds to be exactly the same as the problem I had with the slow speeds on my M4-P. (The slow speeds had become very erratic and 1/1000th second also wasn't giving an even exposure across the frame.) Very simply, after I'd owned it for at least 25 years (and it was at least 5 or 6 years old and well used when I bought it), it needed servicing and after this was done last year (CRR Luton, UK), it's working like new again.

 

[mooge]

The slow speeds work by delaying the closing curtain with the escapement. speeds 1/30-1/15 are with the pallets disengaged and speeds 1/8-1 are with the pallets engaged, using a similar (if not identical) escapement position range to create the delay. The escapement module has no adjustments. Two cams control the position (adjusting amount of delay) and configuration (pallets engaged / disengaged) of the escapement.

Given that some speeds (1, 1/8, 1/30) work, we should expect that at least 1/2 and 1/4 should work too since they are with the escapement module in the same configuration (pallets engaged), just by incrementing the escapement module position (amount of delay). 1/30 works which indicates that the pallets can be disengaged. I wonder if there is a problem with the escapement control cam or the interface between the cam and the escapement that is causing this issue.


(this is a Canon 7 escapement module but the pallet is the telephone shaped thing on the bottom left that makes the buzzing noise)


I don't have an M4-2 but I have an M2 and abuse or excessive wear aside, I don't see how anything could break in the escapement or control cam. The only problem I've ever had with mine is when I put it together wrong and 1/8 became 1/60 (no engagement with closing curtain so no delay). I suggest cleaning with solvent and looking to see if anything is out of place before replacing the escapement module.




I'm not an expert... but this is the internet so here's some more conjecture.

 

[ulrich.von.lich]

Roger, nothing wrong with the expensive wine itself, but I think it's wrong to eat canned spaghetti with it, because you would dishonour the wine.

Mooge, thank you for the valuable information. I realised the information I gave in my original post is not correct. Actually the 1s, 1/2s, 1/4s, 1/8s are OK, while 1/15s and 1/30s are off. The 1/15s lasts as long as 1/2s and 1/30s is somewhere between 1/4s and 1/8s. After reading your post, it seems to make sense. According to you, what would be the reason the pallet cannot be disengaged?

I just realised there is a repair section on the forum. Perhaps this thread belongs there.

 

[mooge]

when you turn the shutter speed dial you turn a stack of cams. one of these cams controls the slow speeds pallet i.e. disengages the pallets for 1/15-1/30. the cam will have a follower that pushes the pallet out of the way for those speeds. I'm not sure why either the cam or follower would have a problem because neither are subject to much force so I'd guess it's just stuck with dried oil or something.

cheers.

 

[Highway 61]

Actually the 1s, 1/2s, 1/4s, 1/8s are OK, while 1/15s and 1/30s are off. The 1/15s lasts as long as 1/2s and 1/30s is somewhere between 1/4s and 1/8s.

This specific problem with 1/15s and 1/30s can happen with most of the slow speeds escapement modules when they are not exactly screwed in their correct position. Loosen the screws which secure the module on the camera chassis, fiddle a bit with it so that it moves back and forth, test the defective speeds, slowly tighten the screws back and apply the same torque on both.