Backhoe Questions on JD 3320 & 448 Backhoe

[rdp58]

I worked a few hours with the backhoe for the first time Saturday . It worked good for awhile, but then the boom and the dipperstick would not work at the same time after dumping the dirt and coming back to the trench. The hydraulics got hot, I touched the metal fittings on the hoses and I could not keep my hands on them. The boom is not smooth, it jerks, but all other controls are smooth. Is this normal for the 448 hoe? Is this something I should let the dealer look at? Thanks for your input on this problem.

 

[kennyd]

This is definitely NOT normal behavior. Is your BH plumbed through a Power-Beyond circuit or to a rear remote?

 

[rdp58]

The backhoe is plumbed into the power beyond.

 

[slaveToHorses]

Almost sounds like you could have something clogging up the control valves.
The boom and dipper should work independantly, so that is an issue.
The boom swing is more jerky than the other controls, by nature. This is especially true if the dipper arm is extended. It acts like a weight at the end of a pendulem. You get used to feathering this control and bleeding off pressure by moving another valve at the same time.

The hydraulics will get hot but I don't recall them being that hot. A restriction would cause them to heat up so this points to the clog theory. Take a soft mallet and wack a few times on the control valves while the tractor is pumping and jog the controls around. Ya never know, it might free it up.

 

[rockyridgefarm]

Good suggestions. Power beyond is the proper plumbing. Check for restrictions. Especially the hydraulic filters. I am thinking the rockshaft filter screen is the likely suspect.

 

[joshinct]

I also have a 3320 and 448 backhoe and do not find it teribly jerky. I alos do not have a problem moving the boom and curling at the same time. I have used the backhoe for about 100 or so hours of use. I typically use it for about 3 to 4 hours straight. I have found the hydraulic cylinders and fittings to to get hot, but not so hot that I burn my hand. I have found that the joysticks are sensitive and that if I gentlyb apply pressure the backhoe is very responsive and smoth. Good luck

 

[cruzr]

I worked a few hours with the backhoe for the first time Saturday . It worked good for awhile, but then the boom and the dipperstick would not work at the same time after dumping the dirt and coming back to the trench. The hydraulics got hot, I touched the metal fittings on the hoses and I could not keep my hands on them. The boom is not smooth, it jerks, but all other controls are smooth. Is this normal for the 448 hoe? Is this something I should let the dealer look at? Thanks for your input on this problem.

I have a 3320 with a 447 BH. The boom on mine is very sensitive and will jerk in the up and down and right to left movements. I have around 60 hours on the backhoe. It is much more sensitive than the dipperstick. I can opperate both the dipperstick and boom at the same time. Maybe the flowvalves can be adjusted, to solve the problem.

 

[hankus]

I have a 3120 with the 447BH. The boom has a noticable jerk in the up direction, but not in the down. The dipperstick and bucket curl motions are very smooth and can be feathered. Also the boom right and left motions can be feathered to a crawl. I thought I might be doing something wrong until reading some of the comments here. I haven't felt any of the metal fittings yet, but I'll check that out. I've only got 15 hours on my tractor, and I'm also wondering if the boom up motion rate is something that the dealer can adjust for me?