The frount end loader bucket on my 416c backhoe when i raise the bucket up to load a truck at height it will start to try to dump itself......it doesnt appear to be a control malfuction at least mechanically...and i have swapped out the bucket roll sensor from another known working hoe ...and disconnected the bucket roll sensor....none of these have affected the problem...i now assume its a hydralic issue but not even sure where to look any thoughts ??
If its a single bucket cylinder machine, it will start to dump the bucket as you lift. There would be a rod that is on the right side of the machine. If its dumps too much the rod might be bent.
Correct. The rack back rod mechanically moves the dump spool via linkages when the loader geometry is toward the top. To check the rod, put the machine on flat level ground and put the bucket flat on the ground. Now on the right upper loader arm boss there is a black stripe that should line up with the indicator arrow on the linkage.
Why do these rods bend? I had two of them to bend on a 420D within approx. 2000 hours. Also, the actuator bent as well. I think I remember seeing other ones at auctions that had the same bend in them, like it went past the stop. I finally took the rod completely off in disgust.
The ones i have seen bent were from abuse and not greasing the pivots and the rod seizing.
Looked this rod over and it appears to be in great condition and as per factory.....any other ideas......this rolling of the bucket happens about when you raise the bucket to about eye level when your in the seat it happens not as a slow process but as a all of a sudden movement maybe a 1/4 rotation of the bucket... any thoughts appreciated
Lets just step back for a second. If this is a single tilt cylinder machine (you have not said if it's single or dual, dual being the IT style loader) than the machine is equiped with a mechanical linkage that will change the position of the bucket as it raises. The purpose is to prevent the load from spilling, over the back of the bucket, onto the hood. So, just to clarify, the bucket should tilt forward as you raise it. What it sounds like is that the linkage is out of adjustment. I have been told by Cat mechanics that the adjustment can be every sensitive so it is difficult to get it just right. My machine has had a similar issue and it can make a bit of a mess when the sudden motion causes dirt to shake out onto the ground. I have found that if you hold the loader control lever to the right as you lift the loader arms you can reduce, or in my case, eliminate the jerky action of the bucket leveling function. When I say "hold the lever to the right" I mean to hold the joystick close to the point at which you are trying to get the bucket to start dumping. As for the mechanical aspects I suggest that you check the adjustment (I can't help you with the specifics here). I would also check the front of the rod, where it connects to the loader linkage for wear or, as Lee pointed out, siezure. The last thing I will mention is to check the linkage where the rod effects the hydraulic valve for the bucket. This is where I suspect the issue may be with mine.
Thank you for the replys Yes its a single cylinder machine from a visual inspection the rod is in factory condition...the connection point of the rod to the loader area is loose and working if anything maybe a bit too loose same for the rear connection...this machine has about 3k hrs on it and most of its ussage was rear and was well maintained not abused maybe i should just totally remove the rod as a test function??? i do not totally understand how to adjust or service the rear rod connection point and actuator other than grease. on my machine holding the loader control right/left while raising makes no difference to this function Thanks
Hi, thanks for much good advice on my cat 416 over the last few years. The self level mechanical mechanism was stopping my roll function. Tried to free it up but after 30 yrs or so it became too difficult. I disconnected it and ensured the bar preventing the roll back was clear and now it works perfectly. Just need to be careful when lifting loads high.