lump 531 Posted January 7 Hello group. Because my parents used to own a very rare 1921 Grant Six roadster (and because I have still have some of their Grant Motors memorabilia), I belong to a Grant Six Facebook group. Today I saw a post from a lady asking for help identifying clutch material (or material from something near the clutch). I figured if there was any group that might be able to assist her, it would be the knowledgeable folks on the AACA forums. So below is her question, and the photo she included. Any ideas? Any Grant roadster owners on here that can help identify the material that this part of the clutch/drive assembly is made from (blue arrow)? My car has 1/2'' conveyor belt rubber. Another car (the one pictured) has 4.5mm laminated stainless steel. Both seem like strange materials for this application. What's correct? Stumped! Share this post Link to post Share on other sites
Tinindian 1,031 Posted January 7 That is a universal joint disc.At least one person on the Studebaker section has/makes these. Do a search. "universal joint disc" or " fabric u-joint" Share this post Link to post Share on other sites
edinmass 2,227 Posted January 7 It is called a "Hardy Disk" and was a common way to connect a driveline back in the day with a car that didn't have very much horsepower. They were originally manufactured by Goodyear. They were die cut, multiple layers with cotton reinforcement back in the day. Today they use rayon. There were bunch of different sizes, and almost none are available today. The Studebaker source is actually from my old shop, which is still making them for water pump drives on several diffrent makes. Your going to have to make one yourself. You need to source the material from a supply house that specializes in rubber products. Convayor belt would be fine IF it is the correct thickness and has the required reinforcement. Do not just cut it with a knife or blade, it should be done with a die in a press. Since you are only making one, turn a thin piece of steel in a lathe and sharpen the edge like a knife and press it out. Do the same for the drive holes. Get it right, or you will have a mess on your hands. Good luck, Ed 1 Share this post Link to post Share on other sites
PFitz 429 Posted January 7 (edited) Thermoid was another company that made them. They were used in many auto and truck drive shafts, water pump/generator drives, some clutch disc hubs until about 1929, and all Franklin cooling fan hubs from the early 1920's until end of production in 1934. They were originally layers of cotton saturated for natural rubber that were then vulcanized in a mold. Even good originals don't last long because moisture wicks into and weakens the cotton, oil and grease softens the rubber, and even if kept dry, the internal friction of flexing during use causes the natural rubber to keep hardening until it cracks. I've pictures of dozens that have failed that way. I've been riveting new ones in clutch discs and cooling fans for about 35 years. A number of years ago I bought out the operation of a man in Connecticut that for many decades had been making the rubberized fabric discs for many cars and trucks, including custom sizes not available otherwise. Modern synthetic rubber and fiber sheet materials are much stronger than the original cotton/rubber discs. I've made many sets of u-joint rings for members on this site. Just made a custom set for a car owner who adapted a different magneto to his teens engine. I can make any size up to 8 inch and any bolt hole size and pattern. If you need help, pm me. Paul Edited January 7 by PFitz (see edit history) Share this post Link to post Share on other sites
lump 531 Posted January 8 Thank you, Paul. I copied your reply and that of the other guys here, and pasted them into that Grant Motor Car Facebook page. I told the poster (Catherine Strutt), that if she wished to be put in contact with you, that I would help her with that. IF she replies, I will do so. Share this post Link to post Share on other sites
PFitz 429 Posted January 8 That's fine, Lump. Thank you. Paul Share this post Link to post Share on other sites
lump 531 Posted January 14 On 1/8/2019 at 12:53 AM, PFitz said: That's fine, Lump. Thank you. Paul Paul, The lady who posted this query on Facebook would indeed like to be put in touch with you. I copied the website address for her Facebook page here, in case you would be willing to send her a message. Catherine Strutt member of Grant Motors Facebook page Thanks for the information, and for hopefully assisting this person to fix their Grant Six motor car. Share this post Link to post Share on other sites
PFitz 429 Posted January 14 I just messaged her on FB to see how I can help. Thank You, Lump for your help. Paul 1 Share this post Link to post Share on other sites
