Hey Guys, I have been surfing these forums for awhile, ever since I wanted to buy a skid steer and then when I had questions and now finally, I have my own dilemma. I have a Case 1816 (not B or C) that has been repowered with a 20hp Onan years back. Bought it not running from a family friend for cheap knowing it had issues with a belt. Well, since then, I have replaced all the chains, had new keyways cut, and installed new bearings and seals. Also got the levers adjusted. The last thing I am fighting is my right side pump melting/shredding belts! To date, I have gone through 8 belts trying to diagnose the issue. At first I thought it was just a cable adjustment issue (this is a manual lever engagement, not electric or centrifugal clutch). I adjusted them in and out, tried a size smaller and a size bigger belt. Currently I am running a pair of A30/4L320 belts. I was told this is a size smaller than stock, but I have them adjusted enough to disengage. The pulley on the right side (issue side) is a tapered bushing sheave. I had to grind the sheave down on the side I am having issues with because it was hitting the engine pulley when disengaged. I have over and over again tried setting up the pulleys for proper alignment. Its as good as it gets. I also checked for angularity and it is better than the other side that has no problems! I don’t think the belt is slipping because, with the clutch engaged, the belt feels very tight. Could it be too tight??? As soon as I start the thing up with a fresh belt, it starts smelling like rubber and starts smoking within 1 min of just idling. I can post pictures and video if needed. PLEASE HELP! I have sunk days worth of work and have easily had the engine out over a dozen times. PS, I am running cheap D&D rubber v belts off amazon prime for 4 dollars… I would blame the belt but the left side belt still is the first one I put on it!
Don't know anything about that particular machine but typically if a belt smokes, its because its slipping. Now if these are v-belts they should be driven by the sides of the belt, not the bottom. So if you have worn pulleys and the belt sits too low, it won't grip the pulley correctly and it will slip.
My thought would be that either 1) the belt IS slipping. As 92U 3406 said, the belt needs to fit the sides of the V and not touch the bottom. The key is surface area. More surface area more bite. If it is the belt slipping you may want to consider going up to a class B size belt if the pulleys will accept them. 2) you are transmitting heat to the belt or pulley from another source which causes the rubber to soften and eventually slip. Not saying this is the case but specially with that Onan, heat could be coming from leaking exhaust blowing on the belt. I ran into that on a sawmill with a kohler one time. All I'm saying is check for any heat being produced near the pulleys and belt. Just a couple of thoughts. Hope it helps. Good luck!
My gut says that the pump is demanding too much torque, either from a bad pump or a stalled circuit.
That was a thought I had as well but I am not at all familiar with this machine. Only thing that scared me away from commenting on that was OP said " As soon as I start the thing up with a fresh belt, it starts smelling like rubber and starts smoking within 1 min of just idling." Assuming all functions are at idle and not dumping over a relief valve any pumps whether open or closed loop should be without load. I would definitely check to make sure you do not have a valve engaged without knowing it and the first one I would check would be the auxiliary flow for attachments because if it is engaged it would be deheading against quick couplings assuming there is no hydraulic attachment hooked up.
Thanks for all the replies! I will start checking some of the suggestions above. To comment, the only thing this pump runs is the right side motor, there is a separate aux. pump for the bucket. If I am not on the sticks and just sitting still (no brake on or anything) at idle, the pump shouldn't be commanding any power, therefore it shouldn't be too much torque, right? Also, I will look into the exhaust leak, but I think the exhaust is far enough from the belt, it shouldnt matter.
Theoretically yes, however you should not rule out the possibility that there may be a problem inside the pump (or even elsewhere in the hydraulic system) that's causing it to load up. Pretty much what BE said in post #5.
So a bit of an update. I noticed the pulley on the pump (the side burning belts) was a bit wider than the rest. Turns out it has a pulley (not original) for 4L/5L belts. I replaced it with the correct diameter smaller width pulley. I put everything back together and started her up. After a bit it started smelling and smoking a belt but now its the belt on the other side! I could barely touch the belt after 30 sec of running. I am convinced now that I just have the manual cable clutch wayyy to tight and some how burning the belts. Like, I almost have to use two hands to engage the belts. I dont have a spring scale so I cannot check the actual tension per the manual but they are TIGHT. So the next time I get a chance, I am going to put some slack into the system to see if that fixes it.
I wouldn't think too tight belts would cause them to slip. Maybe if they were used and glazed from previous slippage. I've been wrong before though. As a quick and dirty check, how much can you deflect the belt by hand. Machine obviously not running when you check.