Very stiff focus ring in Ai-s Nikkor 105mm 1:1.8

Ai-s Nikkor 105mm 1:1.8 with a very stiff focus ring, is not that hard to repair. One of the most important thing when working with old lenses is to remember to set small marks BEFORE take the helicoids apart, and also remember to, AT INFINITY!, measure the distance from the front of the inner helicoid to the very back of the lens body, without the mount. Also remember to measure from the front of the focusing ring to the back of the outer focus helicoid, it's where the index ring sits. Then remember to set a small mark on the inside of inner helicoid barrel and the inside of the back helicoid, BEFORE unscrew, it's the same with the middle helicoid. and count how many turn (s) it will take before the helicoids gets off the thread. I use #10 helicoid grease from Japan Hobby Tools in this lens ( links down in the list ). Here are some link's to different repair tool's and lubricating stuff: "ORBIT" HEPA Blower: https://photosol.com/products/orbit-h... You can buy it here: https://www.adorama.com/cpkhjdb.html "Liqui-Moly" LM 50 Litho HT: https://www.amazon.co.uk/Liqui-Moly-L... "Liqui-Moly" LM47 MoS2 grease with Molybdenum disulfide: https://products.liqui-moly.com/lm-47... or on Amazon: https://www.amazon.co.uk/Liqui-Moly-3... Contact glue: https://www.loctiteproducts.com/en/pr... SpyderLENSCAL: https://www.datacolor.com/photography... Japan Hobby Tool rubber cone: https://www.amazon.com/Japan-Vacuum-C... 18 different size rubber repair tool's: https://www.amazon.com/Sizes-Lens-Fil... Divider Caliper Wing Compass: https://www.amazon.co.uk/Divider-Cali... You can also buy this set. Lens Repair Set with pointed, flat, half flat tips: https://www.amazon.com/dp/B00QRPWCN0/... JIS cross head screw driver's: https://www.amazon.com/Moody-Tools-58... Or this set, that is the set I use: https://eustore.ifixit.com/en/Tools/D... Lens cleaning wipes (PEC-PAD): https://www.amazon.com/dp/B0161VIZZ8/... Thin Cotton Buds x 200 you can buy them here: https://www.muji.eu/pages/online.asp?... DSLRKIT Pro Lens Vise Tool Repair Filter Ring Ajustment Steel 27mm to 130mm: https://www.amazon.com/DSLRKIT-Repair... Japan Hobby Tool Herical Grease (Helicoid grease #10) Made in Japan: https://www.amazon.com/Japan-Hobby-He... Loctite 222 50ml Threadlocker https://www.amazon.com/Henkel-Loctite... And you will also need some Isopropylalcohol 99% And sometimes Lighter Fluid that is very good to clean lens element's. NOTE: Do NOT! use Acetone on platic part's, it will damage / melting the plastic!!!