L48 or L4610?

JATO_RaT · Jan 2, 2002

Re: L48 Loader Problems

John, I just measured my bucket and it is exactly the same as yours and the pivots on the cylinder/4 bar linkage being about 11". As far as the Super UDT and UDT go, I suspect you are correct. I have 2 cut sheets on Super UDT and UDT from Kubota. They have some info but not as much as I would have liked. Once I scan them, I'll post it here and let you guys see. It would appear however that the Super in Super UDT is for the super cold climate more then for the high heat quality/attributes. MChalkley mentioned that he saw a decrease in hydraulic oil temperature when using a pure synthetic (Amsoil) hydraulic fluid. I stilll don't think your problem is so much oil makeup as much as something else. A temperature reading of the oil after the problem shows up again might be very valuable way to help diagnose. Rat...

MChalkley · Jan 3, 2002

Re: L48 Loader Problems

johnjc - I'm concerned about your dealer's recommendation of regular UDT for your L48. I think you should contact the closest Kubota Regional Center, or ask your dealer to do so, if you trust him completely. I was under the opinion that only Super UDT was recommended for HST machines. I don't have any of my old Kubota info, because it went with the L4310HST when I sold it. As Rat mentioned my L4310 performed significantly better when I switched to full synthetic. Personally, I wouldn't use an HST machine with UDT in it at temperatures below 30 degrees or so without extended warm-up time - and before I moved it, I'd put the range selector in neutral and run the HST pedal forward and reverse for a minute or two. This will let the parts warm up and warmer oil circulate through the pump and motor before you put a load on it. And, again, I'd encourage you to think very seriously about the UDT/Super UDT issue, and get the right information from somebody you're sure you can trust. If you can prove your dealer recommended UDT, or preferably that he installed it, then you can get the HST replaced under warranty if it bites the green weenie due to improper lubricant, but I'm sure you prefer to not damage it in the first place. And what if it croaks 5 years from now? How would you ever prove that was because of the wrong lubricant? You'd be stuck with a very expensive bill that you shouldn't have had to pay at all. As you can see, it's not a minor issue. Considering the investment in that fine piece of equipment, semi-synthetic (Super UDT) or full synthetic (such as the Amsoil I use) is very inexpensive insurance.

FWIW, Amsoil synthetic cured the power steering problem you mentioned in my '93 Dodge Cummins 4x4 - and for a lot less than $38/qt - closer to $5/qt, I believe.

johnjc · Jan 6, 2002

Re: L48 Loader Problems

Rat
Thanks for taking the time to check the measurements for me. I had hoped there would be a difference but guess not. Stopped in to talk to the dealer Monday. He doesn't have any idea what to do next. So he is going to have someone from Kubota give me a call. Said It might take a week so. For now the only thing to do is wait.
Started snowing here about 2 hr. ago and we have 2" on the ground. May get to push snow in the morning.
john

johnjc · Jan 6, 2002

Re: L48 Loader Problems

Mark
Thanks for the reply. I am waiting for my dealer to set up a call re the problems with my loader and while I have Kubota on the line I will be sure to bring up the UDT - Super UDT issue. Your idea of putting the Range selector in neutral sounds interesting hadn't thought of it. The Service manual does call for Super UDT for the HST and is optional for the front axle. My old Case 580 won't move until it warms up, when it is below 20 degrees. What I do there is pick the rear wheels off the ground with the backhoe jacks and put it in gear. The wheels just barely turn at a fast idle . After about 15 min. it warms up and everything works fine.
Its worked this way for the 10 years that I have owned it and doesn't seem to get any worse. The fact that the wheels are turning slowly means that some fluid is going through the pump. The pump must caveat when the oil is thick.
John

MChalkley · Jan 6, 2002

Re: L48 Loader Problems

John - I expect the pump does cavitate when the oil is thick - and any pump manufacturer's service information says that cavitation is a major cause of pump failure, so I'd be concerned. Letting it warm up with the wheels off the ground is a very good idea, too. I forgot we were talking about a machine with stabilizers on the back. Most folks don't have that luxury. /w3tcompact/icons/smile.gif

johnjc · Jan 8, 2002

Re: L48 Loader Problems

Got my call from the Kubota factory service rep today.

First there is an update to the hydraulic leveler that he described as an additional stack on the valve. Told me that It would increase the curl uncurl force. Said he would call the dealer with the part numbers. When I ask if this was a service bulletin he said it wasn’t published yet .

Next - Told me that there is a detent when you push the loader control hard to the right. Its function is to purge air that enters the cylinder when the bucket dumps faster than the pump supplies fluid. This makes the cylinder give when draging the bucket backwards.
I never noticed this on mine will have to check for it when I get time

Next – questioned me about the temperature of the hydraulic oil. Said it normally should go no more than 100 degrees above ambient temperature.

Next – He is going to have the dealer check the hydraulic pressure when the tractor is hot. This may be hard to do because it takes about 3 hr to get hot. Told me it is normal for it to drop up to 100 pounds when hot any more is a problem.

Next – I ask about using Super UDT vs UDT . He told me that it was formulated for cold operation problems on shuttle shift transmissions. And that it wouldn’t cause any problems with the HST . Said that it is thinner when cold but when hot both types have the same properties.

JATO_RaT · Jan 9, 2002

Re: L48 Loader Problems

John, thanks for the info. Keep his number handy as I may want to find a direct chance to find out more regarding my situation.

The following is a little information about 3 hydraulic oils, Kubota UDT, Super UDT and Amsoil SAE 30 ISO 46.

Respectively in this order UDT, Super UDT, Amsoil

Kinematic Viscosity @ 100 deg C 9.5 9.0 9.3

Kinematic Viscosity @ 40 deg C 60 45 50.1

Viscosity Index (ASTM D-2270) 140 192 171

Pour Point deg C -35 -46 -40

It would appear that the Kubota Super UDT has the best cold performance of the 3, but I'm no oil tech and can only guess that based on what common sense tells me. The info about Super UDT also mentions superior "lubrication" at high temperatures where as the UDT does not. I think based on what Kubota tells us and what MChalkley has experienced using the Amsoil product, it might be best to use either the Super UDT or perhaps Amsoil type synthetics particularly for the cold weather attributes. Rat...

johnjc · Jan 11, 2002

Re: L48 Loader Problems

Bad News
Stopped by my dealer's at lunch time to check on the new valve section that the Kubota Rep had talked about, and it turns out that it is one of the parts that were already installed in my loader.
Kubota told the dealer to install a gage so that I can watch the pressure while it is working.. So we will see where that leads.

Anonymous Poster · Jan 12, 2002

Basically from a dealers stand point, we look at the L48 as a machine destined for people in the industry; landscapers and contractors who need/want a smaller TLB, in many cases we have sold them to contractors who have nursed older Case 480 TLB in hopes that Case would introduce a lighter line of TLB than the 580 again. The price issue is a little strong for most residential customers to justify when compared to the L4610. The other thing to cosider is this; the L4610 is an L4310 with a couple more HP and a heavier front axle for increased loader capacity. The couple HP will NOT show up appreciably when running your implents, and is'nt enough jump to justify bigger implements, so unless you NEED the increased loader capacity, why not grab an L4310 and save a few bucks? This attitude shoews in our sales...we sell LOTS of Kubotas, quite a few L4310's, a respectable number of L48's, and about 3 L4610's since their intro. Pete

JATO_RaT · Jan 14, 2002

Pete, as a owner of a L48, no doubt you're correct about the L48, its just a heavier tractor with a few more features and even some less options (ie. transmission) then either the L4310 or L4610. I myself would not have even considered the L4310 over the L4610 simply because in my opinion, you can never have to much loader power. That plus a few extra HP as mentioned, larger front axle, larger hydraulic pump volume and more powerful steering definitely would shift me to the L4610. Here in CA its probably different then in NY as I believe the L4610's out sell the L4310's. The few thousand extra one pays for the L4610 over the life of the tractor is miniscule. Thanks for the information, Rat...