I recently bought a used L4701 HST with 50 hours on it. At about 65 hours i let a stick knock the hydraulic filter off breaking the filter base. I lost majority of the fluid. Once i replaced the filter base i bought 5 gallons of hydraulic fluid at TS that ended up being way thicker than what came out. I put enough in to get the tractor out of the woods and back home. Once i got it home i decided to drain it completely and put all new UDT2 in it since it’s supposed to be flushed at 100 hours anyway. Once that was done the transmission screams a louder than it did originally and regardless of load. Previously it would scream when going uphill or under serious load. Has anyone else experienced this? Is UDT2 the right fluid for L4701 HST in Alabama? Dealer claimed that the only difference between UDT and UDT2 is price and the UDT2 maintains viscosity in super cold weather. He tried to sell me UDT but manual calls for UDT2 so i used it.
L4701 HST Hydraulic fluid
- Thread starter JWesB
- Start date
fried1765
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Equipment
Kubota L48 TLB, Ford 1920 FEL, Ford 8N, SCAG Liberty Z, Gravely Pro.
I think your dealer probably gave you good advice, but others here are far more knowledgeable about such things.
North Idaho Wolfman
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L3450DT-GST, Woods FEL, B7100 HSD, FEL, 60" SB, 743 Bobcat with V2203, and more
It's SUDT2 and UDT.
And there is the possibility that the cheap hydraulic fluid damaged the HST.
I would run it a while and see if the noise goes back down.
This screaming, could it be considered a whine? That’s what I hear on the HST Kubota CUTs when operated in High range (pretty much only for transit) or with too much load in Medium range. Really have to get aggressive (abusive?) to get much of a whine in Low range with the half dozen Kubota HST CUTs I’ve operated.
I seriously doubt the flavor of Kubota UDT matters much. It probably had Super UDT2 as a factory fill. My older L came with UDT in it. When I changed it I put in Super UDT2, no change in function or sound. I live where there are maybe 10 days a year that get below 32F (and maybe one day in 5 years below 25F). The local dealer only stocks Super UDT2.
Since you had to replace the filter base, is there anyway something up in the trans might have gotten dislodged when the stick had its way with the machine?
I seriously doubt the flavor of Kubota UDT matters much. It probably had Super UDT2 as a factory fill. My older L came with UDT in it. When I changed it I put in Super UDT2, no change in function or sound. I live where there are maybe 10 days a year that get below 32F (and maybe one day in 5 years below 25F). The local dealer only stocks Super UDT2.
Since you had to replace the filter base, is there anyway something up in the trans might have gotten dislodged when the stick had its way with the machine?
Trapper Bob
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L4701, Wicked grapple, 6’ bush hog, pallet forks, 7’ box blade, 6’ Wicked bucket
My 4701 “screams” under a load. The intensity of the scream is proportional to the amount of the load. It is possible you hurt the transmission with the wrong fluid. Could it be possible you are hyper-sensitive to the noise since you know there might be a problem? I would run it a while & see if a problem occurs. Good luck! I believe you will be fine.
TheOldHokie
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L3901/LA525, B7200DT/B1630, G2160/RCK60, G2460/RCK60
When in high range and heavily loaded my L3901 howls like a Banshee. Mid range is quieter, low range even more, but when stalled they all howl.
When I was test driving machines at the dealership i about jumped out of my skin first time i touched the pedal on an L3901. Salesman assured my it was normal. It was not - selector was in high range and parking brake was still set. Tells you something about salesmen.
Dan
