Bob Nakon 55 #1 Posted May 3, 2018 Hi Gents, My C120 is surging, like it goes and then it coasts and then it catches and goes....etc. I have been advised that it is likely the key in the hubs. Does anyone have a drawing of this hub ? Is it a square key or a Woodruff key? Are the hubs difficult to remove? Thanks for any help, Bob Share this post Link to post Share on other sites
pfrederi 17,518 #2 Posted May 3, 2018 It is a woodruff key. If it is surging because the keyway has gotten sloppy then the hub will usually come off easily...but you will probably need a new hub or even a new axle if the keyway has been badly damaged 2 Share this post Link to post Share on other sites
stevasaurus 22,528 #3 Posted May 3, 2018 Along with what Paul said...assuming this is a manual transmission...the hubs and the hub bolts with lock nuts would be the 1st thing to check. For a drawing...go to the Manual section on the main page and look for your year and model number. It could be a worn belt or worn clutch spring. Some more information and a picture (we love pictures) would help. 1 Share this post Link to post Share on other sites
Bob Nakon 55 #4 Posted May 3, 2018 Thanks for the response guys. I went over the tractor 2 years ago and replaced a lot of worn parts. I put on a new main drive belt, new clutch spring did a lot of adjusting and so on. What I don't get is when I go down a slight grade it just starts to coast til it levels off and then the drive kicks in. I'm thinking the easiest thing is to check the hubs, right? What if one key is sheared off but the other is not, would it act like this? Bob 1 1 Share this post Link to post Share on other sites
RandyLittrell 3,862 #5 Posted May 3, 2018 When my 1277 throws a woodruff key it doesn't move. The one axle just spins. I don't thinks its a woodruff key, but I would check that first. Randy Share this post Link to post Share on other sites
stevasaurus 22,528 #6 Posted May 3, 2018 Bob...I am starting to think you do not have a problem. Wheel Horse with their belt drive would really act like what you have going on. I think in their manuals, they suggest that you only go up hill and not down. A little more history here would help us...like how long have you had this horse? did you mow with it OK before and now something is not right?? Did you change things (like he belt) because of what you have going on?? Tell us what you think is going on with some history of your horse. 3 Share this post Link to post Share on other sites
Bob Nakon 55 #7 Posted May 3, 2018 Stevasaurus, I have owned this tractor for 15 years. I use it for everything. It has always run well and never done this hesitation thing before. I replaced the belt because the old one was making noise and I decided to replace/adjust everything else that it needed. I know something is wrong. If a sheared key in one hub shuts down the machine then it has to be something else. I'm thinking the tensioner/idler whatever pulley behind the right-side cover. Or maybe something in the transaxle? I hope not because that is one area I have never gotten into, except for topping it off. I'm replacing the turbine housing on my TracVac right now and not having any fun with it. Set screw on the turbine won't come out. Tomorrow I'll go after it with a carbide drill and hopefully it comes out. Then the C120, although I'm really not sure what is wrong now. Bob Share this post Link to post Share on other sites
953 nut 54,380 #8 Posted May 3, 2018 1 hour ago, stevasaurus said: I think in their manuals, they suggest that you only go up hill and not down. How will I get back down to the Barn? 2 4 Share this post Link to post Share on other sites
Bob Nakon 55 #9 Posted May 4, 2018 I think a high-banked oval in a steady left turn just kinda creep down ½ a lane at a time. Made for retired Nascar drivers. 1 5 Share this post Link to post Share on other sites
Ed Kennell 37,492 #10 Posted May 4, 2018 Have we verified this is a gear drive? Sounds like the common Sundstrand drift to me. 2 Share this post Link to post Share on other sites
Bob Nakon 55 #11 Posted May 4, 2018 Hi Ed, It is an 8 speed. 1 Share this post Link to post Share on other sites
Ed Kennell 37,492 #12 Posted May 4, 2018 (edited) Does it drift in all gears Bob? I would look at the tranny input shaft key. Edited May 4, 2018 by Ed Kennell 1 Share this post Link to post Share on other sites
Bob Nakon 55 #13 Posted May 4, 2018 Yes Ed, it does it in all gears. Uphill it is fine but on level ground or a down slope it happens. Bob Share this post Link to post Share on other sites
KC9KAS 4,741 #14 Posted May 4, 2018 (edited) I started a comment before reading the entire thread....then I had to enter something! Edited May 4, 2018 by KC9KAS 1 Share this post Link to post Share on other sites
953 nut 54,380 #15 Posted May 4, 2018 7 hours ago, Bob Nakon said: Yes Ed, it does it in all gears. Uphill it is fine but on level ground or a down slope it happens. Bob If it is pulling fine up hill I doubt that it is a broken key anyplace. Going down hill the engine compression is attempting to hold you back, but on a steep grade it would not be sufficient in any gear. I have a very precipitous portion of my driveway that will over rev the engine in any gear if breaks are not applied. Share this post Link to post Share on other sites
stevasaurus 22,528 #16 Posted May 4, 2018 It is not the transmission. It has to be something with the belt and pulleys. Make sure the belt is the right one and the right width. It should be a cloth covered belt also. Take off the guard and belt and clean the pulleys with mineral spirits. You are going to have some drift with a belt drive system, but it should catch up before you level out. You probably are doing this already, but if not, I think using 1st gear when going down hill should help. I hope the advise works for you Bob. I can't test it out here in Illinois...we don't have any hills. Illinois is flat. 1 2 Share this post Link to post Share on other sites
Bob Nakon 55 #17 Posted May 4, 2018 stevasaurus, I'm thinking you are right. I'm going to check the hubs, put a mark on the shaft and hub and see if they shift. Then I'll take off the cover and look at the belt. I get all my parts from the Toro dealer and the belt is dealer stock, no substitutions. It could be the tensioner pulley I guess, it is spring loaded as I remember. I wish I had a diagram. 1 Share this post Link to post Share on other sites
WHX?? 48,067 #18 Posted May 4, 2018 1 hour ago, Bob Nakon said: I wish I had a diagram. Have you got the manuals Bob? Might be one in there? Get some pics of how the belt is routed and put them up for us. Share this post Link to post Share on other sites
953 nut 54,380 #19 Posted May 4, 2018 3 hours ago, Bob Nakon said: I wish I had a diagram. This manual could be helpful. Share this post Link to post Share on other sites
roadapples 6,983 #20 Posted May 5, 2018 On the opposit side of the tension pulley check the spring pin holding the clutch lever to the same shaft. Had one shear off on my loader tractor. Sometimes it would work and sometimes not. Gave me a fit 'till I stumbled on to it... 3 Share this post Link to post Share on other sites
Ed Kennell 37,492 #21 Posted May 5, 2018 Me thinks Jay is the winner. I actually bought a tractor for cheap. The PO said the 8 speed was bad. I found the 1/8" spring pin sheared. 3 Share this post Link to post Share on other sites
ronhatch 406 #22 Posted May 5, 2018 Bob;, Pull the hubs and trans drive pulley, check the keys and keyways,then let us know what you find. thanks, Ron Share this post Link to post Share on other sites
ohiofarmer 3,249 #23 Posted May 5, 2018 I went through this with mine having the exact same symptoms. The woodruff key had widened the slot in the axle. My best guess is that it had about eight inches of play in the wheels to the ground.. Your axles are also damaged. My tractor had been used for snow pushing and I think that activity is hard on the axle keyway. One of our members here made a copper woodruff key and added weld around it to repair the axle. The copper key idea is that weld will not stick to copper. Mine was repaired with JB weld [put Pam cooking spray on a new woodruff key so it is not welded to the axle] which is fine for mowing grass but not for pushing snow. If you keep using the tractor in its present condition,your wheel hub will break. DAMHIK 1 Share this post Link to post Share on other sites
kasey54 305 #24 Posted May 6, 2018 I've had something similar on a b-80 , and an 875. One gear drive, one hydro . I don't think either was as badly worn as yours is. On each tractor the issue was the fit of the woodruff key between the axle and the hub. On close inspection I determined each had a bad key way in the hub , and a worn key. While I'm sure the axle's must have had some wear also, they fit with new keys quite well. I had access to a broach kit and made new key ways in the hubs. I installed new woodruff keys , drilled and tapped new set screw holes into the hubs at the new key ways, and added a second set screw because the hubs were thicker where the original key way was. It really surprised me how sloppy the old seemingly not too worn key was in the new key way of the hub The new key fit the original slot in the axle with no feel of slop. I assume as brand new the key would have been tapped into the axle slot. I tightened them well with new set screws with the concave tip that cuts slightly into the shaft , or key when you tighten them . loosen them . and tighten them again. Incidentally when I jacked each side up and rocked each wheel to see if it was loose (before the fix) the loose ones were easy to feel. Its been two years now and each is still working fine with no loosening. Hope you beat it! Share this post Link to post Share on other sites
wallfish 16,780 #25 Posted May 7, 2018 Up hill the key grabs the sloppy worn hub slot, down hill the key is forced to the back of the sloppy hub slot then surges to the front when it levels off. Flat ground while turning, it's gonna do the same thing as going down hill. The key isn't sheared off, yet. But if one or both of the hub slots are worn, it could cause this condition. That pin Jay suggested is a good place to start too but it seems belt slipping would probably happen more while going up a hill. Could a cracked frame at the trans also cause this condition? IF, the axle and hub key slots are worn. Could you just drill and tap holes 1/2 way in each piece then lock it with long set screws? (backyard hammer mechanic style) Those axles may be hardened and tough to drill. If so, the drill bit will want to drift into the softer hub. Probably not the proper fix but to me if both pieces need to be replaced anyway, no harm no foul. Hopefully the axle is good and replacing the keys and hubs will do it. It could be just one side. Just kind of "thinking out loud" and typing it. 1 Share this post Link to post Share on other sites