Yashica Mat 124G focus knob grinding

[Joe Galloy]

A Mat that I bought a couple of years ago has just started to exhibit a slight but noticeable "grinding" feel along with resistance when the focus knob is turned in certain places. Has anyone experienced this and know what the cause is? Thanks.

 

[BrianShaw]

If the camera had not been dropped or the like, I would guess that, at a minimum, the lube in the focus mechanism has failed.

 

[Dan Daniel]

A few things can cause this. A bent axle or a bent side plate- one reason to always store a TLR in the infinity position; I even rack it back in walking down the street to avoid it being bumped. Sand or such in a variety of spots.

Focus in and out and watch the lens unit very carefully. Watch for any wobble or binding in the movement. Lightly rest a finger on one side then the other while focusing to see if you can feel variation. This is the important issue and a sign of real trouble. Grit or binding in itself is annoying and not good in the long run, but having the lens moving erratically out of alignment should be looked at soon.

 

[Joe Galloy]

If the camera had not been dropped or the like, I would guess that, at a minimum, the lube in the focus mechanism has failed.

Thanks for the suggestion - the camera hasn't been dropped or knocked since I've had it, and although I'm the second user the first appears to have barely used it (almost factory fresh condition).

 

[Joe Galloy]

A few things can cause this. A bent axle or a bent side plate- one reason to always store a TLR in the infinity position; I even rack it back in walking down the street to avoid it being bumped. Sand or such in a variety of spots.

Focus in and out and watch the lens unit very carefully. Watch for any wobble or binding in the movement. Lightly rest a finger on one side then the other while focusing to see if you can feel variation. This is the important issue and a sign of real trouble. Grit or binding in itself is annoying and not good in the long run, but having the lens moving erratically out of alignment should be looked at soon.

Thanks for the suggestion. I'll look for variation while moving the lens unit and report back!

 

[shutterfinger]

Download a service manual parts breakdown here: https://www.manualagent.com/yashica/mat-124g/repair-manual

 

[Joe Galloy]

Focus in and out and watch the lens unit very carefully. Watch for any wobble or binding in the movement. Lightly rest a finger on one side then the other while focusing to see if you can feel variation. This is the important issue and a sign of real trouble. Grit or binding in itself is annoying and not good in the long run, but having the lens moving erratically out of alignment should be looked at soon.

Dan, I did check this last night. There is no visible wobble, and my attempts to find any variation with light pressure didn't go anywhere...until I noticed that the focus knob was turning smoothly with no grinding feeling. I worked it back and forth and it was gone! My hopes were instantly dashed when I applied light pressure to one side and found that the issue returned. It only grinds around one spot, roughly where the 3.3' to 4' marker is on the knob.

 

[Joe Galloy]

Download a service manual parts breakdown here: https://www.manualagent.com/yashica/mat-124g/repair-manual

Thanks for the manual. I wasn't aware that one was available. I've leave this to a professional because I'd likely turn it into a hunk of junk. I see that Mark Hama has been a popular choice. Does anyone know of others who service Yashica Mats and have a good reputation?

 

[paul ron]

take the view finder off and you can see the focusing axle. while in there, remove and clean the mirror.

 

[removed account4]

Thanks for the manual. I wasn't aware that one was available. I've leave this to a professional because I'd likely turn it into a hunk of junk. I see that Mark Hama has been a popular choice. Does anyone know of others who service Yashica Mats and have a good reputation?

both zacks camera repair ( apug advertiser ) and midstate camera repair in RI are be good choices. they both take
cameras through the mail. and both most likely work on yashicas.. zacks has an in house machine shop in case he has to fabrcate parts ...
good luck !

 

[Joe Galloy]

both zacks camera repair ( apug advertiser ) and midstate camera repair in RI are be good choices. they both take
cameras through the mail. and both most likely work on yashicas.. zacks has an in house machine shop in case he has to fabrcate parts ...
good luck !

Thanks!