My lens helicoid grease turned into glue overnight

I was fixing a 1980s Nikon 50mm f/1.4 lens last Tuesday and everything went smooth until I hit the helicoid. The old grease had turned into this hard sticky mess that felt like chewing gum stuck in there. I tried to rotate it with my spanner wrench and it wouldn't budge at all. Ended up soaking the whole helicoid in lighter fluid for about 6 hours to break it down. That did the trick but then I had to clean every thread with a soft brush and alcohol before regreasing. Has anyone else run into old lubricant that solidifies like that on vintage glass and found a faster way to deal with it?

3 comments

3 Comments

knight.uma16d ago

Just toss it in the trash and buy a new lens, that old junk isn't worth saving.

fionat5516d ago

...and here I am thinking my biggest lens problem would be trying to get the glass clean, not fighting a lost battle with fossilized grease. I swear that Nikon stuff is just ancient superglue in disguise, my spanner wrench almost took a chunk out of my finger when I tried to force it. Glad your lighter fluid soak worked, (I just know I'd have set my whole workbench on fire trying that trick).

nancyramirez16d ago

Oh man, that old Nikon helicoid grease is legendary for turning into concrete. Had the exact same thing happen on a 28mm f/2.8 a few years back. Lighter fluid soak is the way to go, but a faster trick I found is using a heat gun on low setting for a few minutes before the soak. It softens that glue enough to get the helicoid moving without warping anything. Still have to clean every last bit with alcohol though, no shortcut for that part. The worst is when the grease has crystallized into little hard chunks that scrape your threads. At least you got it sorted, that 50mm is worth the hassle.