RTV-X1100C - VHT extreme shake

TimDSM

New member
Hey fellas. I have a Kubota RTV-X1100c that I recently purchased used. Runs and operates great but has developed a pretty extreme shake when accelerating in any drive gear. I have narrowed down the problem to be transmission or hydraulic related. I am hoping that maybe I've missed something, and someone could shed me some light, before resorting to unnecessarily replacing parts..

Here's what I know:
The engine revs great (in neutral).
The machine does not shake as excessively when lifted off the ground.
The shake is caused when the machine is under load.
Axles and driveline is straight and tight.
Oil levels are topped off.
Filters have been replaced.
I have not tested the charge pressure yet.
I have replaced the charge pump suction hose, old hose was not collapsed.
Cables are snug, adjusted to remove excess slop.
Top speed is 22 mph in the air, 18 mph on the ground
 
Hey fellas. I have a Kubota RTV-X1100c that I recently purchased used. Runs and operates great but has developed a pretty extreme shake when accelerating in any drive gear. I have narrowed down the problem to be transmission or hydraulic related. I am hoping that maybe I've missed something, and someone could shed me some light, before resorting to unnecessarily replacing parts.. Here's what I know: The engine revs great (in neutral). The machine does not shake as excessively when lifted off the ground. The shake is caused when the machine is under load. Axles and driveline is straight and tight. Oil levels are topped off. Filters have been replaced. I have not tested the charge pressure yet. I have replaced the charge pump suction hose, old hose was not collapsed. Cables are snug, adjusted to remove excess slop. Top speed is 22 mph in the air, 18 mph on the ground


i would bet your problem is injector related.
 
i would bet your problem is injector related.
Thanks for the reply. Have you seen this problem before to make you suspect that it's injector related? The injection pump was replaced in march, by the previous owner, before I purchased it. I do not know the condition of the injectors or if they were replaced as well, only the pump was noted in the service records.
 
Thanks for the reply. Have you seen this problem before to make you suspect that it's injector related? The injection pump was replaced in march, by the previous owner, before I purchased it. I do not know the condition of the injectors or if they were replaced as well, only the pump was noted in the service records.


start it up and break one injector line loose at a time. if one isn't working then there shouldn't be any change when that cyl is broken. since the pump has been off it could also be a timing issue.
 
start it up and break one injector line loose at a time. if one isn't working then there shouldn't be any change when that cyl is broken. since the pump has been off it could also be a timing issue.

We've since tested charge pressure, reads ~84psi

Also tested injectors by opening each line individually and did not indicate any problem with the injectors. The machine engine still runs smooth.

Much of the hydraulic oil is dark. We are considering replacing the oil and possibly trying to flush out the old. Any thoughts?
 
all of your rubber motor mounts and vibration dampners in good shape? when you broke the injector lines one by one did you notice the engine miss each time you broke a line?
 
I bought one once that had the harmonic balancer put on 180 degrees out. Shook like crazy. Take the balancer bolt out and see if the dots are lined up.
 
Is this the old style with ujoints in the rear like on the earlier RTVs? If so, I was wondering if the rear ujoints had been replaced and were out of phase???? Just a question and not saying that's it but if they have indeed been replaced I'd look at that. if the old style.. If so, see post on "rear ujoints needed again" for complete information or just for the phasing info see https://www.nettractortalk.com/forums/threads/rear-vibrations-after-a-u-joint-change.13755/ . The post there by Kanook has a good picture and Mark has one too. If out of phase ,will act like you mentioned.
 
Got around to investigating this kubota. Unfortunately we've found excessive metal, including chucks, in the hydraulic tank. We are debating to either open the case or just find/purchase a replacement.
 
thanks for letting us know. can't hurt anything to open it up to see what failed. we can learn alot and who knows it might be repairable
 
I'm pretty sure you'll find that the hyd pump piston has come apart. It's repairable for about $1500 worth of parts. I've done 2 of them with the same failure.
 
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