Jacobs Super chuck rebuild

[PT Doc]

I had a USA 18N chuck that was difficult to open, so I pressed in a part, degreased everything and used Super Lube as the grease on the innards. It is very smooth now but it seems like maybe the Super Lube was too thick. I bought a unused NOS USA 18N, and that chuck just spins open really easily. It must have a heavy oil or thin grease inside. The Jacobs chuck rebuild info says to use a “good grade of grease.” Kind of vague. Super Lube is NLGI 2. I have a bunch of options in my shop. I have Mobil synthetic NLGI 1 and 2 grease, Mobil Vactra 2 way oil ISO VG 68, Mobil DTE 24 hydraulic oil light, hydraulic oil AW ISO 32, white lithium grease, 50 wt oil, 10 wt oil, 5w30 and 10w30 motor oil.

I just got a USA NOS Jacobs 11N that is really sticky. I wasnt to get this little guy running nice and smooth. What lube would you recommend that will allow the collar to spin easily but be effective on keeping the bits inside well lubed? Thanks in advance.

 

[mksj]

Nice review of rebuilding the chucks by darkzero, recommended not using grease for the balls but oil, I would use Vatra #2 as a medium weight oil with tachifiers. He recommended grease for the scrolls, probably use a sythetic NGL1 or some light moly grease. See video where he also uses moly for the balls. I have some high speed moly grease in a small tube, it is very light grease for use in high speed ball bearings, that may also be an alternative. I have seen some older chucks where they used thick grease and it dried out and was thick and difficult to turn, using some oil helped clean out the grease and restored smooth function. I have a Jacobs 14N that has work great for years, surprisingly holds very good accuracy and have not had to rebuild it yet. My other mill chucks are Llambrich .

Jacobs Ball Bearing Chuck Rebuild (14N) Done My Way

I wasn't going to document this as I'm sure there are plenty of posts on how to do so on the net. But what the heck, here it is my way, more like a refurbish since my intent was not to replace anything. Plenty of pics so beware.... First off, I'm a keyless chuck guy, they're what I prefer to...

www.hobby-machinist.com

 

[EmilioG]

SuperLube clear grease works just fine. A little SuperLube oil on the balls/race is also helpful.
Jacobs chucks are very simple in their design. Any long term grease that won't dry over time will work.
Albrecht uses a green PAO thickened lithium grease that is difficult to source in small quantities, so I just use SuperLube products and they work fine.

 

[PT Doc]

I decided to use white lithium grease in the 11N. It cleaned up super well and is super smooth. My NOS 16N is so freaky smooth that I might press it apart just to see what is inside. I’ll try way oil on the next rebuild.