JD 3720 CUTS HST Sluggish

   / JD 3720 CUTS HST Sluggish #22  
Just might be talking about different filters in this thread... from what I'm reading.
 
   / JD 3720 CUTS HST Sluggish #23  
The inline filter as it is refereed to here or also the "charge inline filter" located along the side of the engine,simply supplies "charge oil and make up" oil to the hydra static pump. The hydrastatic pump sends oil to the hydrastatic motor in a closed loop and not back to the sump. Any oil that is lost through case leakage is made up by the charge pump, aka power steering pump at 219~290 psi.
 
   / JD 3720 CUTS HST Sluggish #24  
Yeah, There's the big round filter under the sump down bottom, and the inline screen filter on the side above the oil level. You won't lose fluid above the level of the reservoir unless there's pressure (which there isn't when its not running).
 
   / JD 3720 CUTS HST Sluggish #25  
Belzington or Deere Dude, did either of you ever get your problems solved? My 3120 just started the exact same behavior!
It use to move slowly at an idle, and increase speed linearly with increased rpm's. Now it barely moves in any gear unless I rev up over 1500+. Cold or warm.
I found something interesting when checking inline filter/screen... it was crushed flat (sucked flat??). Had to be majorly restricting flow, and who knows for how long. But I temporarily removed the screen all together and tested and made no difference. So coincidence??
Hoping you guys solved your issues??
 
   / JD 3720 CUTS HST Sluggish #26  
When cold, mine would hardly move until I ramp up RPM to above 1500. Until then it was very slow. Still does, at times at 1100 hours. Mine seemed to have gotten bad after my first transaxle oil change.

One thing I noticed, when the dipstick showed 1/2" below full, it was actually 1.5 gallons low. After I topped it off with lo-vis it seemed better.

After subsequent oil and filter changes, sometimes when idling the tractor when cold it will move very very slow until I boost the RPMs above 1500 and when above 1800 it starts acting like it should.

Generally when warmed up a little all is good. Filters always look good with no debri.
I would be nervous with a filter sucked flat. Chances are it was crushed at install.

Mine seemed to get better after using it a few times and only is irratating at cold idle for the first minute.
 
Last edited:

Tractor & Equipment Auctions

2006 CHEVROLET EXPRESS SERVICE VAN (A51219)
2006 CHEVROLET...
2019 FORD F550 XL SERVICE TRUCK (A51243)
2019 FORD F550 XL...
CFG MH12RX Mini Excavator (A49461)
CFG MH12RX Mini...
2015 CATERPILLAR D6T LGP CRAWLER DOZER (A51242)
2015 CATERPILLAR...
1997 GROVE TMS750B 50' TON CRANE (A51222)
1997 GROVE TMS750B...
2017 F-550 Bucket Truck (A51039)
2017 F-550 Bucket...
 
Top