Fixing a Broken Nikon Lens Mount

Introduction
There are more than a couple Nikkor lenses out there that for some reason Nikon decided to use a plastic lens mount instead of a metal mount. Models include the 18-55 DX and 55-200 DX in both non-VR and VR variants. It doesn't take much more than an accidental drop or knock and the plastic tabs will break off and the lens wont be able to mount to the camera body. Luckily this is pretty easy to fix. Searching around after doing this I found similar repair guides written up here and here.

Disclaimer
I should make a short disclaimer that performing this kind of minor surgery on your lens yourself will most likely result in any warranty you once had to be void. In addition, any damage you my cause is not my responsibility. You should take due caution to be careful to not damage your lens including covering the glass lens elements as needed.

So Here Goes

What you will need:

Spare Part
: I gave the Nikon Parts Department a call (number is at the bottom of the link btw). A friendly Nikon service rep answered the call and helped me. A few days later my part arrived at my door stop. $15 all up.

Tools: #0 and #00 Phillips head screwdriver. If you dont have these, a precision screwdriver set is readily available from Amazon for less than $10.

Optional: Second set of hands will prove helpful for the reassembly process.

The replacement F-mount is a plastic unit, just like the broken one. It has an attached cable and a thin piece of plastic that protrudes out for a few cm, make sure you note where that plastic comes from when you remove the old bayonet mount.

Figure 1. Nikon 1C999-601-2 replacement plastic bayonet mount.

Place the lens with the mount pointing up. Looking at the F-mount, you will see 3 large screws (all three visible in Figure 2). I used my #0 Philips head to remove them. I put them on a piece of paper and labeled them to make sure I remembered where they came from.

Figure 2. The old lens mount with broken tabs.

Next its time to remove the screws from the collar. Note there are two sizes here (Figure 3). I removed the medium screws with a #0 and the smaller with a #00 Philips head. Again, separating them on a labeled piece of paper makes reassembly that much easier. Admittedly if you it wouldn't be too hard to figure out where they go if you did mix them up.

Figure 3. Screws on the collar. From memory there were two medium and 3 small screws.

Now its time for the fun part. Using gentle force you can remove the center most ring. Next the tab that houses the electric contacts can be removed. It's attached to a ribbon cable so all you need to do is gently lift and remove. The tension of the cable will pull the piece downward. Let it rest inside the lens. Next is time to remove the plastic bayonet mount. This piece is attached to a small cable you will need to unscrew (#00 Philips screwdriver).

Figure 4. Removal of the plastic bayonet mount.

Unscrew the cable from the old bayonet lens mount and attach it to the replacement unit. I found that juggling the small cable (which is spring loaded), holding the bayonet and screw driver easier with a second set of hands. No doubt you could do it on your own though...

Figure 5. Transplanting the internal cable from the old mount to the new. Kudos to my mate Kevin for being the extra hands.

Once done, the new bayonet can be put in its new home. Make sure to line everything up and pay special attention to the two metal shims under the bayonet which may have moved during the surgery. They can only go one way. I used my small screwdriver to help line everything up.

Figure 6. Lining up the shims before putting the bayonet in its new home.

Once that's done, screw it in place with the large screws. Next, the tab holding the electircal contacts can be gently lifted back in place. It should lock into it's home position. The final piece to go back on the lens is the center ring. There are two ways to put this back on. First method is to put the ring back in place and use a screwdriver to push the aperture controlling tab into position (Figure 7).

Figure 7. Moving the aperture control tab with a screwdriver.

The second method is easier. Simply use the gap made for the tab on the center ring to push the aperture control tab forward as you slide and push down the whole center ring down, locking it into place. It is much easier to do, than it is for me to explain. I think Figure 8 shows the process reasonably well.

Figure 8. Second method for putting the center ring back in place.

All you need to do now is put all the screws back into the lens and you have successfully repaired your lens. After I was finished I noticed that a stray finger had made its way onto the rear glass element. A quick brush and polish with a lens pen will take care of this.


Figure 9. Finish up the repair with a good cleaning.

Put it back on your Nikon SLR camera body and enjoy the fruits of your labor!

52 comments:

Anonymous said...

Brilliant description! Thanks for the info - same steps apply for the Nikkor 18-105 VR G lens. BTW part # for that THAT lens is 1C999-729-1. Nikon Canada charges $10. Beats whatever a repair shop would ask! Again, thanks for the great details!

Nate said...

Great, I so am glad it helped you. And thanks for posting the part number for others to use on the 18-105 VG G. Nothing better than saving hard earned dollars!

Graham One said...

thanks so much. just had a minor fall, and snapped the mount flanges. Really happy I don't need to buy a brand new lens.

Nate said...

Go for it Graham! Hope it goes well for you and you can get back to doing the things we photographers like doing best!

Miroslav said...

Thank you. Just found my body separated form lens. I'll order part tomorrow and it should be done asap!

It seems that this bayonet is fragile on every Nikon...

Nate said...

Hi Miroslav,

Yes, all the plastic bayonet's are fragile. Glad to hear you can get yours fixed.

Anonymous said...

Thanks just fixed my 18-105 following your instructions. Replacement part from eBay and your instructions for the win.

Thanks from Tampa.

Anonymous said...

Thank you for the great advice! However, in the process of removing the mounting bracket, the small cable that is attached to the spring loaded mount disconnected. Has anyone else had his happen? I would like to make the repair myself if possible but I don't even know what the cable is for! Any information would be greatly appreciated.

Nate said...

Did you unscrew it or pull it from the solder? Or even cut it? Obviously if you unscrewed it, you need to re-attach//screw it back on. Otherwise you will need to solder it on. You'll need some solder and a soldering iron with a finer tip. Your local Radio Shack should have both of these. If you need some new wire, RS should also have some fine gauge wire as well as wire cutters (get the ones that strip many different wire gauges).

As for soldering, I learned from some of the many excellent tutorials from the internet. I'd recommend doing the same.

RodneyT said...

Tutorial is excellent. Everything is working. Thanks!!!!!!!!!!!!

Anonymous said...

Mine broke, going to fix after seeing this. Thanks!

Tammy said...

Thanks so much! Excellent repair guide. I was able to fix the lense mount only to discover that the lense is still not working. I can see what looks like a ribbon that is loose. Is this something I can fix or do I need a professional help?

Nate said...

Is the cable loose because it is a flexible cable or is it loose, as in, it has come out of the socket it's attached to? If it's the latter, you may need to tear down the lens or send it off for professional help. I'd search around the net first and see if there is instructions for a tear down. (iFixit?)

Otherwise, there are plenty of good, QUALIFIED Nikon repair centers around who could look into it.

Anonymous said...

Are there metal mounts available to replace the cheap plastic ones?

Fernando said...

THANK YOU!!!! This is a terrific tutorial and even gave the part number for my 18-105 VR lens. Many thanks!

Would it be cheaper to order the part from Nikon directly or should I look into other sources?

Nate said...

Anonymous: I don't think there are metal mounts. I remember asking the Service Department at the time of my repair and the answer was no. Wouldn't hurt to call and ask them though.

Fernando: I would think that this is a Nikon only part. I have bought other parts for my gear from an approved repairer and the cost was the same as directly from Nikon.

Anonymous said...

Thanks for the detail! On the weekend the mount broke on my 18-105 VR lens. I called Downtown Camera in Toronto and confirmed the lens was still covered by Nikon's 5 year warranty however it would cost $40 to ship it to Nikon Canada. I called Nikon Canada, the part (number 1C999-729-1)costs $8.72 plus $15 for shipping; I ordered two. The parts arrived via Purolator on Wednesday. With one small Philips screw driver in hand, 5 minutes later the lens was as good as new. This lens is well used with over 20K pictures, I am sure the plastic mount will break again. Thanks for this blog, it gave me the additional nudge to fix it myself.

Anonymous said...

Thank you mate !
God that sensor was a b**ch to solder.

I cant understand sy they do not make the new lenses with metal mounts. My older Nikon D1 / Nikkor lenses are all metal mounts. Far more durable.

Anonymous said...

Can I take the metal mount off of a broken AF-S Nikkor 18-70mm dx lens and put it onto my 18-105 lens that works but has the broken plastic mounts?

Anonymous said...

I have a new Nikon 18-105 lens and an old Nikon
35-70 mm lens with a metal mount. Can I replace the plastic mount of the 18-105 with the metal mount of the Nikon 35-70. If not can I ask a nikon
shop to replace the plastic mount with a metal one.
Thanks
Sam

zoran said...

Nate thanx so much for the great help on an issue that all of us Nikon fans are facing!
Its true that there are no metallic mounts that will fit the 18-105lens BUT here is a guy that made metallic mounts possible!!
http://forums.dpreview.com/forums/readflat.asp?forum=1030&message=39014692&changemode=1

Anonymous said...

I got the part and when it came to the part with the small wire... well I should have went for those second hands. I'll have to solder it back, but I also lost that little metal thing that has the 2 holes... one for a screw the other goes over a little nub, it holds that spring loaded part in place. I need to find a replacement for that but have not been able to yet. Any help is appreciated!

pckpck said...

Just called Nikon to get the bayonet mount unit for the 18-105 lens. Unfortunately, it is no longer available from them. Have to take the unit by a repair station or ship it to Nikon.

Ctown Veto said...

awesome, got mine done in 10 minutes with the new part. my only advice is have great light while working on the lens.

M said...

I had the same problem as Tammy above on July 14, 2011 12:02 PM. The auto focus works, but the shutter does not deploy now. Any idea whats wrong? Also, what role does the flexible white wire play? and what role do the CPU points play? I guess I am trying to figure out what deploys the shutter when the lens is mounted on the camera. Thx

Irwan said...

Thank you. I save my 18-105 with this instruction.

Scooter said...

Easy fix, instructions are accurate. I winged it and the only challenge is disconnecting the f-stop/aperture spring and reconnecting it. Some kits have this as part of the repair, mine did not.

Sure wish there was a metal option for the repair because I know it will break again. I guess it is better to have it break than have the screws strip out of the cheap plastic body.

They certainly cut corners on this lense

Anonymous said...

There is someone selling a metal mount for the 18-105 on ebay. I wonder how well it works? Anyone every try it?

Anonymous said...

"There is someone selling a metal mount for the 18-105 on ebay. I wonder how well it works? Anyone every try it?" Same Question Here

flyfishinchristian said...

I had a similar experience as above. Nikon put me hold for a nice long while, before explaining that they don't sell this part anymore, but they'd be happy to fix it if I sent it in... So, I am trying a 3rd-party option I found on Amazon.

zcea pcchaeo said...

i´d my 18-105 lens bayonet broken as well.. as some anonymous asked here about that little cable the small cable that is attached to the spring loaded mount, mine is disconnected and i thought i was fu***ed the lens automatic fuctions...but anyway i put all the screws together and when i try it the lens worked like a champ :D

nice review... althought i lost like 3h makin all this not 5 minuts :D the screws are to to tooooo tiny dam it :D

Mario Alvarez said...

I snapped the small wire in figure #5.

What is it called?
What is its function?

I did not get it when I order the bayonet ring. I'd like to replace it even though lens seems to work without it.

Anonymous said...

ANyone know what that wire that fastens to the mount controls? Mine came loose....... I am thinking it does autofocus as the metering seems to be fine Thanks

Anonymous said...

I think that small wire is responsible for VR. Not sure. It would be great if someone could confirm.

Anonymous said...

My Husband called to get this replacement mount sent to me and he was told that they don't send out that part and that we would have to ship them the whole lens for them to repair. What do I do now?

Stacey said...

Thanks for this great tutorial! After reading this, I found the (plastic, ~$8) bayonet mount on eBay. I had to do a few extra steps since my replacement piece didn't include as much as your part (no spring/piece that protrudes), but these instructions were great for getting me going. For that last part, I was able to twist out the inner piece with that protruding plastic and unhook the spring, then do the reverse to attach it to my new mount. Thanks again for saving me a couple hundred dollars on professional repair or replacement!

DAM said...

Yes I have the same problem with the little cable came off the spring screw when I tried to move it. Im going to place in between the plate and the black top and hope it makes a connection...I'm waiting for an answer from Nikon Canada to see my options....Other than that your instructions were awesome. Thanks for the DIY info.

Evan Turkon said...

The part is no longer sold by nikon

Anonymous said...

i found a metal mount for my 18-105 on ebay, Just fitted it and it is a great deal sturdier.
http://www .ebay.co.uk/itm/110767488438?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1497.l2649

On a side note ive just discovered that my auto focus isnt working...its not a huge deal as its still better than no lense (plus I can manually focus) buuuut, if anyone knows where I might need to go back and look at to potentially fix this that would be great. I swapped it following the above instructions.

Oh, also I managed to break the solder on the little wire, but I managed to strip and re-secure it with a bit of fiddling, so don't panic if you dont have a soldering iron and do the same.

Andrew MacDonald said...

I've followed the guide and the new mount is now attached properly as planned. Unfortunately, now once I zoom in, say to 105 (on 18-105 lens) and zoom back out it reaches 35mm and jams. Any idea what this could be? Once I take the lens of the camera, the zoom easily goes back to 18mm, it is only when mounted to the camera this issue occurs.

Any advice is greatly appreciated :)

Anonymous said...

Hi
I have bought the new lens mount but it doesn't have the cable attached. Is this a problem? Do I need to buy one with the cable attached?

Anonymous said...

The little wire which was soldered broke quite easily. I guess I can solder it back on. Do I need any special solder? I live in rural Guatemala. No camera repair people here but know a jeweler who is pretty good with fine work. Hope he can help. I also am having difficulty connecting the little spring. Any suggestions on how to easily attach the spring?

Masha said...

Got it fixed, no autofocus and slow shutter speed. What did i do wrong? please help

James Rhodes said...

Just a little helpful hint. Those screws that you refer to as "Phillips" heads, are actually called Japanese Industrial Standard or JIS for short. They look similar because they were actually the forerunner of Phillips screws.
The difference is that on a Phillips head the inside corners of the screws and the drivers are slightly rounded, forcing the driver to lift up and spin in the screw head, an action known as "cam-out", thus showing that maximum torque had been achieved. JIS lack this rounding and are truly X shaped, thus allowing much more torque to be applied without rounding out the screw.
As long as they aren't very tight a Phillips head screwdriver may work but if they are, there is a good chance that they will strip out, leaving you with a whole new problem.
If you are going to work on cameras or pretty much anything made in Asia a lot, they may be worth your money. A good way of identifying JIS screws, other than the perfectly square inner corners, is a little dot stamped inside one of the corners, like +X except a real dot.
Google JIS screwdrivers and you should find a number of them on Ebay and Amazon.

Anonymous said...

I love the 18-105mm lens because it is versatile and after 5 years I accidentally dropped it and it snapped open. Part of the flange on the retaining rim broke so it wouldn't fit tight unless I press the lens against the body to keep all electronic contacts intact. I finally ordered 2 sets of the covers from Nikon Canada in Ontario. Pity they closed out the repair depot in all other provinces and now if you need any repairs or parts you got to go through head office in Ontario. No idea why for 2 small parts they had to ship via Courier Service and came in a BIG box with lots of air bubble foam inserts. They said with the Purolator so they could keep track of the order and they charged 20$ for something less than couple ounces. They would not ship via other means. To remove and replace the broken parts was relatively easy except that black wire is not soldered on but rather a small rubber cap you just snap it off and on. Now the only parts I need to replace is that big piece of rubber band around the lens. It is not that bulky and still they want to ship it in a big box which is a nuisance. If I can find a generic parts I would just that Nikon is still selling this rubber band for an archived item.

Unknown said...

I snapped the wire on my Nikon lens and freaked about! So that's how I found this site. I read several comments with the same issue and figured out how to fix it. The black cap is just that and it uses the pressure of the wire to lock in place. You will have to CAREFULLY strip some plastic off the wire. I used a small curved trim scissors that I knew were sharp. I just pressed down enough to be able to pull the plastic and expose the wire...you don't need much and since you will be taking away, your length will be less to work with. Once you expose your wire, you'll have to place the black cap on to the wire (don't let it slide into the camera body). Before I forget, I worked on a white towel to keep pieces from bouncing off the table. I placed the 3 hole plate on the pin and placed the wire on the pin (down far enough to lock in place) and slid the cap on with a LITTLE pressure and it worked!

viter dayunior said...

Yes thats my question too, i want to know whats that thin wire is for because i can not solder it back i assembled the lens without this wire connected and it seems no problem the camera is still working, lens and body focus drive is working perfect. But Im still worrying about that wire.

Unknown said...

There does not appear to be any electrical path for this wire. It probably has no function with the plastic mount

Unknown said...

There does not appear to be any electrical path for this wire. It probably has no function with the plastic mount

Tex said...

Nikon U.S.A. refuses to sell 1C999-729-1 but says that this is the same part they use to repair the lens themselves at a cost of $99-$160 plus shipping and insurance. No way to tell ahead of time if it will be $99 or $160. I got the part on e-bay, performed the 10 minute repair at a cost of $42. Works like a champ.

Tex said...

Nikon USA refuses to sell the part but admits that it's the same one that they use to repair in their shop for $99-$160. No way of telling if it will be $99 or $160 in advance. Paid $42 for the part on e-bay and it works like a champ.

Purnima Chhabra said...

Hi, I know this thread is from a few years but just a query. We replaced the mount but now everything seems very dark... something wrong with the aperture I think but. It sure if we need to redo the mount??

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