adsm08 2,759 #1 Posted April 18 I have been having repeat failures of the PTO foot control on my 855. The setup itself seems basically sound, it's the cotter pin at the pedal that is the weak link. I was just wondering if anyone has designed something better. If not I'll have to get out my FTEMAB hat, but I also don't want to reinvent the wheel if someone else has already worked something out. 1 Share this post Link to post Share on other sites
Achto 28,897 #2 Posted April 18 (edited) 2 hours ago, adsm08 said: it's the cotter pin at the pedal that is the weak link. Do you have a washer on the shaft behind the cotter pin? Even a very thin washer will help keep the pin from failing. All else fails, maybe a roll pin would be a better option ??? Edited April 18 by Achto 1 1 Share this post Link to post Share on other sites
adsm08 2,759 #3 Posted April 19 (edited) 2 hours ago, Achto said: Do you have a washer on the shaft behind the cotter pin? Even a very thin washer will help keep the pin from failing. All else fails, maybe a roll pin would be a better option ??? I'm not sure a washer would help much. A roll pin would be useless. I don't like to assume what other people know, but I'm not sure you have the setup envisioned properly. The cotter pin is inserted upward through a hole in the pedal and then opened. The folded end creates a loop that the spring attaches to. The force of the spring is too much for the pin and eventually it straightens and pulls out. The roll pin wouldn't provide the loop, and I'm not sure a washer would prevent the straightening. Edited April 19 by adsm08 2 1 Share this post Link to post Share on other sites
wallfish 17,578 #4 Posted April 19 37 minutes ago, adsm08 said: The force of the spring is too much for the pin and eventually it straightens and pulls out. Seems as though the pin being used is too small or not bent properly and or the spring is too strong. Maybe post a pic of the cotter pin inserted and bent. It should be very very difficult to pull a properly sized and bent cotter pin back out through that hole. 1 Share this post Link to post Share on other sites
Chaz54 73 #5 Posted April 19 Would a small eye bolt work? 1 Share this post Link to post Share on other sites
Racinbob 11,771 #6 Posted April 19 (edited) There's got to be an issue causing the problem. Wrong pin, wrong spring, excessive wear, something. I as well as many here have used that setup for years with no issues. As Dan mentioned, a washer helps. I always use one. That picture would help. Edited April 19 by Racinbob Share this post Link to post Share on other sites
ebinmaine 70,996 #7 Posted April 19 10 hours ago, adsm08 said: I'm not sure a washer would help much. A roll pin would be useless. I don't like to assume what other people know, but I'm not sure you have the setup envisioned properly. The cotter pin is inserted upward through a hole in the pedal and then opened. The folded end creates a loop that the spring attaches to. The force of the spring is too much for the pin and eventually it straightens and pulls out. The roll pin wouldn't provide the loop, and I'm not sure a washer would prevent the straightening. I agree with the above comments on the cotter pin being a likely fault point. I find that modern new cotter pins are incredibly soft and weak in comparison to some of the downright artillery grade ones I'm replacing. The cotter eyelet has the spring retention job. The rest of the cotter has the job of holding itself in place. If you could get a looonnger cotter you'd have more "wrap" around the pedal pivot shaft to allow more holding. Another possibility would be to use a pin one size up and also longer. Drill the hole just enough to clean it out for the next size. 1 Share this post Link to post Share on other sites
adsm08 2,759 #8 Posted April 19 11 hours ago, wallfish said: Seems as though the pin being used is too small or not bent properly and or the spring is too strong. Maybe post a pic of the cotter pin inserted and bent. It should be very very difficult to pull a properly sized and bent cotter pin back out through that hole. 2 hours ago, Racinbob said: There's got to be an issue causing the problem. Wrong pin, wrong spring, excessive wear, something. I as well as many here have used that setup for years with no issues. As Dan mentioned, a washer helps. I always use one. That picture would help. Up until the end of last summer the pin and spring were the ones that the tractor came to me with. The spring looked original, the pin, who can say, but it finally broke. I had it pulled through as far as I could to still have it work and then wrapped it back around as far as it would go. 1 hour ago, ebinmaine said: I find that modern new cotter pins are incredibly soft and weak in comparison to some of the downright artillery grade ones I'm replacing. I am really wondering if this is the issue. The metal just isn't what the designers had originally. 1 Share this post Link to post Share on other sites
Achto 28,897 #9 Posted April 19 14 hours ago, adsm08 said: I'm not sure a washer would help much. A roll pin would be useless. I don't like to assume what other people know, but I'm not sure you have the setup envisioned properly. Now I'm picking up what yer laying down. I just put all this together on my 633. Have not used the PTO on it, probably never will but at least it all there. Could you drill the hole out and use a thicker cotter pin? Might help compensate for the new cheaper metal. Share this post Link to post Share on other sites
WHX?? 50,860 #10 Posted April 19 6 minutes ago, Achto said: Could you drill the hole out 3 hours ago, ebinmaine said: Drill the hole I have this thing about removing old metal ... 8 minutes ago, Achto said: at least it all there. Yes sir better than getting lost in a parts shed ... 1 Share this post Link to post Share on other sites
adsm08 2,759 #11 Posted April 19 I'll look into drilling it. It's together for now, we will see how long this one holds up. Amazingly, the other end, which I just today realized is also a cotter pin, is still together, however the angle the stress is placed on that one is different. 2 Share this post Link to post Share on other sites
ebinmaine 70,996 #12 Posted April 19 6 hours ago, WHX?? said: I have this thing about removing old metal ... I absolutely agree with that but not to the cost of discontinued use of the machine. When I say drill out the hole I'm talking a literal 64th of an inch being removed around the outer diameter of the bore. It may already be worn or rusted more than that. 1 Share this post Link to post Share on other sites
peter lena 9,104 #13 Posted April 20 @adsm08 a base line for me on any linkage lever set up , is to firm up connection . insure lubrication , and verify what is / isn,t working . would only use a drawing set up as reference , and try / test / try as you go . more often than not , the change was easy , went to each stage / point of function , might also try a , HITCH PIN CLIP , instead of a cotter pin , for easy stage test , done a lot of typical original set up mods , more often than not , VERY SIMPLE HOLD CONRTOL , MOVEMENT EASE . have also added a HEIM JOINT , to any ANGULAR PUSH / PULL , CONTROL SPOT , my gain on plow frame , set up function , was really simple , also used a roller stool , so I could easily , stay right there , for every , intended move . try / test / try . just my experience , to a repetitive problem , pete Share this post Link to post Share on other sites
