Hi I just recently purchased a 2004 337 g excavator. It has 3000 hours and is in excellent shape. Very tight and no leaks. I have a question on the swing. When I have the stick fully extended away from the machine body and swing at full speed for 180 degrees or more and stop the machine clicks about 3 times before stopping. It does not do this when the boom is closer to the body, or if I counter swing to the opposite direction during full rotation / speed. Full 360 degrees rotation is smooth and has plenty of swing power. I was wondering if this is normal for Bobcats. I have a Takeuchi 135 that does not do this but does not stop as quickly at full extension as the Bobcat. I really love the 337. Tons of power and very smooth. Such a big step for me from the Tb135. Thanks for helping.
I don't havve a 337 (I have a 435) but I have not had, nor heard of this issue. Obviously there is much greater leverage against the swing brake when you are trying to stop a full extended boom, at full swing speed, than when the bucket is closer to the house. At 3,000 hours it may be possible that you have some wear at the swing brake. Just to make sure you understand the mechanics (maybe you already do-if so my apologies), the swing brakes is like a clutch pack that resides on top of the swing motor. When not on use (the swing motor) a spring applies pressure to the pack, thus acting like a brake. Whenever you ask for the machine to swing hydraulic pressure is sent to a piston that over rides the pressure exerted, on the pack by the spring, thus releasing the brake. Whenever you ask the swing to stop (by centering the lever) the spring pressure takes over again, thus applying the brake. In theory there should be smooth application of the brake-no clicking. It could be that there is debris between the brake plates. It could be that there are grooves on the backing plate (not allowing the plate to engage smoothly) but I would imagine that this would make more of a chattering than (3) clicks. It's possible that the bolt are coming loose on the swing motor (visual inspection should reveal this) or youy could have something as simple as dry ring and pinion gears. They require daily lubrication. Have you greased them regularly? I would start by checking the simple things.
Could quite possibly be with the swing break. I just bought the machine off my bobcat dealer on Friday. I will pull the floor plate and check the bolts, and I will grease it also. I did not do this yet on the machine. Thanks
i have had this issue on 2 of our 435's. However it's more of a chattering rather than clicking, I have sent both machines to my local dealership to be told there was nothing wrong with either machines...I promptly told them that if it's a normal thing i will be sending in our other 2 435's to be adjusted as they don't make the chattering noise (being a smart ass) However, i have noticed that if any of the other functions are being operated at the same time (common in normal operation) then the chattering goes away...so my assumption is the hydraulic pressure on the release on the swing brake is alot higher and uncontrollable for the circuit when releasing without any other circuits being used causing an aggressive application of the brake. If that makes any sense....However, this was well over 1500 Hours ago on both machines and they are still going strong.