RK55 HST slipping probelm

[Littlegrey20]

Good evening all,
Sorry for the wall of text but I know having more information is helpful most of the time.

I have a RK55 that's developed an interesting probelm. Started around 30 hours, with the backhoe still attached I experienced a bit if slipping when going forward uphill but could turn around and back up the hill no problem.
Talked with the guys at RK and they suggested changing the filters, which I did and it didn't make any difference. Took the tractor back to them and they kept it for a while and felt they had solved the problem. Changed out a valve on the wet lines.
Once I had the tractor back home I took the backhoe off and all was well.
I plowed the garden with it, bush hogged several times and never had a problem until I hooked the backhoe back up.
I was demoing an old house and there's a fairly steep hill going up to it. I made several trips up and down the hill then the problem returned. I couldn't pull the hill without the tractor lunging. The engine speed stays the same but the tractor just loses momentum.
I figured it's the backhoe that's causing my woes so I unhooked it and continued on without it. Problem was still there just not as severe.

Let the tractor sit for a week and did the 50 hour maintenance then hopped back on to do some more bush hogging and it was running fine.
Another week goes by and it starts the same problem back up. I decided to try keeping the engine below 1500 rpm and see how it did and I had absolutely no problems. I kept it this way for the majority of the day as I was clearing brush but by the end of the day even with the rpms pinned to 1500 it started back.
I'm planning on taking it back to Rural King but would like to know what's going on incase it's something I can fix here at home.
First HST tractor but not my first tractor over all.

Thanks!

 

[oldnslo]

Does this tractor have front wheel assist? If yes does it operate the same in both two wheel and four wheel drive?

curious if possible there is a tire slipping on a rim causing this random problem

 

[Littlegrey20]

Does this tractor have front wheel assist? If yes does it operate the same in both two wheel and four wheel drive?

curious if possible there is a tire slipping on a rim causing this random problem

It does have four wheel drive and the rear tires are filled but it's not slipping on the rim. It does this in both two and four wheel drive.

 

[Deere Dude]

Are the RPMs 2000+ when this happens. What gear (low-medium-high) are you in when this happens.

 

[Littlegrey20]

Are the RPMs 2000+ when this happens. What gear (low-medium-high) are you in when this happens.

It does it in all gears.

 

[oldnslo]

Little grey,
You state the engine speed does not change when this problem occurs but does it sound like the engine is working harder or really no change in sound either?

do you hear any different sounds when this happens?

 

[Littlegrey20]

Little grey,
You state the engine speed does not change when this problem occurs but does it sound like the engine is working harder or really no change in sound either?

do you hear any different sounds when this happens?

There isn't any noticeable difference in the engine noise. If i have the auto throttle button turned on the engine free revs after hitting 17-1800 rpm.

The only noise that does happen is a whining noise that's similar to when you bog the tractor down in too high of a gear. Sounds like a hydraulic noise instead of engine noise.

 

[CH4Ohio]

It does it in all gears.

Just to confirm . . . You say that it does this in Low RANGE and Medium RANGE too? Your RANGE selection doesn't change anything?

 

[rgr33]

Is it possible you are operating in too high a gear for the work you are doing?

 

[5030]

if I'm not mistaken you can turn up the fluid pressure to the hydro but you'll need a shop manual for the correct values.