I Still Hate My Tractor

[kuboman]

Thats the same banjo bolt my 5740 has and the turbo is still turning on it. There will be a lot of oil come from that at 60 psi!

 

[The Fred]

Thats the same banjo bolt my 5740 has and the turbo is still turning on it. There will be a lot of oil come from that at 60 psi!

Kuboman could you pull it to verify hole size? I know it's a lot to ask. I work on so many turbo cars (mostly euro stuff) that has full holes through the banjo bolts, all the restriction is through the turbo plate/orifice.

I have pix just can not believe the orifice would be there and not in the turbo itself. 1.5mm hole is TINY! This is a single 1.5mm hole, not even drilled all the way through the udder side. Just one hole.

Thanks! Fred

 

[bandaidmd]

If you go to big on the line feeding the turbo it may pull down your overall oil pressure. had that happen to me on a truck that i added full flow bypass filters on. Theres not a unlimited amount of extra oil flow avaiable.

 

[GolfAddict]

Dos Equis. "I don't always complain about my tractor's horsepower. But when I do, I put a turbo on it." The most Interesting Tractor Owner In The World.

:laughing::thumbsup::laughing::thumbsup:

 

[kuboman]

Kuboman could you pull it to verify hole size? I know it's a lot to ask. I work on so many turbo cars (mostly euro stuff) that has full holes through the banjo bolts, all the restriction is through the turbo plate/orifice.

I have pix just can not believe the orifice would be there and not in the turbo itself. 1.5mm hole is TINY! This is a single 1.5mm hole, not even drilled all the way through the udder side. Just one hole.

Thanks! Fred

Yep you bet, I will try and get that done today. Just got another dump of snow to deal with on top of the 4 ft we got already. Arrrgggg.

 

[TripleR]

Right. I noticed the naysayers are starting to be outnumbered by us Fred fans. I appreciate the work of the entrepreneurial members on this forum.

I believe that is because there are really two separate issues:

1. Is the L3940 truly a "gutless wonder" or is there something wrong with this tractor?

2. Will adding a turbo increase power?

In reading the reviews and knowing someone who owns an identical tractor, no one reports the problems described in this and other threads. So many advocate making sure there are no underlying problems.

Adding a turbo has been used for years and is accepted as a good way to produce more power, so no real arguments there, just that adding a turbo will only enhance performance not fix an existing problem.

There appears to be several layers to this.

 

[The Fred]

Fred, sorry to hear this. I've got the same tractor and overall I'm pleased with it. I've only got about 35 hrs on it so far though. I've mainly ran two implements so far, a 6 ft new Landpride cutter and an older 6 ft extremely heavy duty 35 series box blade. The box blade alone weighs roughly 1300 pounds. Believe me, loaded with dirt, it's a load.
At first, like you, I was disappointed in the power. But I'm figuring out how to use the HST+ to maximize power vs speed. I too live in a hilly terrain area and usually find myself in L gear when working an implement. I've also found when cutting tall grass or climbing hills when cutting tall grass it's best to disengage the throttle auto advancing feature and set the engine RPM to match 540 ish PTO speed. From there you can control the ground speed using the foot control or the cruise control lever. Depending on what I'm doing, for example mowing a large field or grading a long drive, I use the cruise lever. Using my left hand to control the ground speed gives me quite a bit of control, after I got used to it. I still leave Stall Guard activated, so if I hit tall thick grass suddenly, it just slows down.
I mowed the same 25 acre field with this tractor with 105 degree temps outside, air blasting, within 10 minutes of my best time on a 70 hp tractor. Ran the RPMs up manually, used cruise. Worked great. Someone recommended the DK-40. This would be a similar method of running that tractor. I've spent some time on a DK-40 cab too, I like the Kubota.

As to cold starts, I've never tried to start it using one cycle below 25 degrees or so. I always cycle twice below 25 degrees. Old habit starting a Ford 3000 Diesel. But, with two cycles mine fires right up even down around zero.

I have noticed, like you, that operating the FEL while moving can cause the a jerk in motion. I'm assuming that the HST needs hydraulic pressure to operate. Using the loader will cause a sudden drop in pressure. Of course the severity would depend on the pumps ability to recover, which, in this case, depends on RPM. Remember that using the throttle advance and the foot feed basically matches the engine RPM to the current load, nothing more. Other HST equipment I've ran has similar
results, unless it has two pumps. With other tractors, like the DK -40 for example, if you match the same conditions you will get similar results. That being said, I think the loader is a bit weak. But it really isn't causing the problem.

Without comparing your tractor to mine, from the seats, it's hard to tell. But, it sounds like you have something wrong. I'd call Kubota directly and see what they say.

This gent and oversized who's brother has one both have similar explanations as myself. I feel I have covered the bases engine wise with the exception of the cranking compression not matching ther workshop manual (400 vs. 530 psi). Unless it is a hydraulic power robbing issue what else could it be. The gent from Messick's and my dealer both said they rarely get power complaints with this model. Maybe there's a rag stuck in the intake??

Maybe I'm just a power freak or simply put just a freak. Either way the show goes on.

Back to the turbo oil line fittings, obviously if I had bought them from Kubota I wouldn't be questioning the size of the orifice, these are from a boy ricer rocket place. This is the first time I have run into a question about oil line restriction, if this was a ball bearing turbo I could see why the small size. I've had a few Mitsibushi turbos apart before and they need pressurized oil to the sleeve bearing which has a tiny oil restrictor built into it and the thrust plate. Hate to tear up a new turtlecharger from oil starvation, best to start big and cut back the flow.

Fred, measure twice cut once and weld 3 times. Check out the tiny orifices in these bushings, same turbo as mine. Hard to believe 1.5mm hole will supply the pressure for 5 of these oil passages.

http://shopping.kinugawaturbo.com/td02td025td03turboturbochargerrebuildrepairkitflatback.aspx

 

[Baby Grand]

I believe that is because there are really two separate issues:

1. Is the L3940 truly a "gutless wonder" or is there something wrong with this tractor?

2. Will adding a turbo increase power?

In reading the reviews and knowing someone who owns an identical tractor, no one reports the problems described in this and other threads. So many advocate making sure there are no underlying problems.

Adding a turbo has been used for years and is accepted as a good way to produce more power, so no real arguments there, just that adding a turbo will only enhance performance not fix an existing problem.

There appears to be several layers to this.

As to bullet #1, would a restriction in the flow out of the hydraulic pump create all of the described gutlessness symptoms? If so, then bullet #2 may become irrelevant.
In other words: adequate pressure from the pump, but at restricted flow. If so, then increasing power may not change much if the restriction is downstream from the bypass valve.
Not naysaying, per se ... just sayin'.

 

[V1Rotate]

If there is a restriction to the hydraulic system's oil flow, the temperature of the fluid would increase sharply.
While running the tractor, use a laser infrared themometer to check the oil temps at various points in the system.

 

[The Fred]

Hydraulics stay cool.

Fred