Aftermarket Kubota Parts

[GeoHorn]

In as much as I'm not nor do I profess to be an electrical whiz (and don't want to be), I'll take your experienced word for it. However, having said that I am planning on converting both my Kubota's to 12 volt electrical cooling fans this summer and I'll make a thread concerning that and the results at that time. The 9 is already half there and has been for years., to enhance the heat transfer of the ac condenser under the bonnet.

One thing you state that I've never seen and that is a painted alternator. All the ones I have ever seen or replaced have been mill finish aluminium pressure die cast bodies.

Amperage draw on both my units is not that much as I run 100% LED lights. and I think (not 100% sure) that both my M's have 55 amp alternators.

If the amp draw is so crucial why do most vehicles today have electric cooling fans versus mechanical ones. I think the answer is they are more efficient.

The re-painted remark was in reference to automotive "rebuilt" parts in general not anything specifically. The 60Amp Delco-10 alternators are all painted black, however...at least the two I've installed on Ford N-tractors and the one on the Buick I gave to my granddaughter for a college runabout.
Your LED lighting is a great way to reduce demands on the alternator. I have a 22-LED bar-light on the front of my Kubota sitting on top of the grill-guard. Works great.. but IT DRAWS 10 Amps, as much almost as the OEM incandescent headlamps and the work light. If idling, the 40A Kubota alternator cannot supply enough to run them all (I installed an Ammeter on my Kubota and can watch the charge rate.) It can only develop a surplus of 5-10 Amps while mowing (2000 RPM) at nite running all the lights.

To answer your question regarding most vehicles today running electric cooling fans.... if you look at the specs you'll see they have alternators rated at 100 Amps or MORE. My six-year-old 2012 Ram pickup with the small 4.7L V-8 came standard with a 160-Amp alternator! (It has both an engine serpentine-belt-driven fan AND an electric fan which runs at certain times and/or with the AC.) Even higher-capacity was available special-order. (And even my old 1978 Ford F-150 ranch-junk-truck came standard with a 70A alternator. No problem for any of those to run an electric cooling fan ...although the F-15- had a common fan-belt fan.)
It's a simple matter to look at the specifications of the equipment being considered and adding up all the amps to see if whatever system you're looking at can handle it. Generally speaking, it's good practice to never exceed 80% of capacity with usual loads. If you don't know the Amps but the dataplate gives the Watts instead, it's a simple conversion to make: Volts X Amps = Watts So Watts / Volts = Amps. The common 75 watt headlamps (incandescent) on my M Kubota running at 12 volts draw 6.25Amps,... there are two of them so that's 12.5 Amps used by the headlamps alone. The Hazard lights are another 8A and the instrument panel is another 4A so that's almost 25A original equipment. Adding my 10
A LED bar puts my little 40A alternator OVER the 80% recommended continuous load, ...so I don't run the headlamps simultaneously with the LED bar. (They don't do much more than light up my FEL bucket anyway.)
Hope all that helps.

 

[dlundblad]

That is not correct. The alternator output is regulated by the regulator (hence it's name) and when the battery is fully re-charged after engine start the regulator reduces the Field voltage which in-turn reduces the output of the alternator (and subsequently the alternator does not require as much energy from the engine.)
An electric fan (or any other accessory) will draw from the battery and the regulator will then demand more from the alternator to keep the battery at full charge. The additional output from the alternator will require more HP from the engine to produce it, ... Therefore, no free ride (but it's a miniscule drag on the engine relative to the need to motivate the tractor so engine/fuel economy is virtually unmeasurable for the average guy)...HOWEVER the alternators on most Kubotas these days are 40 Amp units. If you are running lights or other accessories an added electric fan may exceed the alternator capability to keep the battery fully charged. This may result in a discharged battery at the end of the operating period...OR it may wear our your alternator prematurely due to increased demands.

On another note regarding aftermarket parts for a Kubota: The genuine Kubota 40A alternator is priced in the several hundreds ($299). An identical unit sells on Amazon for $62 https://www.amazon.com/Electrical-A...sr=8-6&keywords=kubota+alternator+34070-75601 which comes with the computer test analysis from the mfr'r (which may be the same who makes it for Kubota because I cannot tell the difference. When I took the genuine Kubota alternator off and opened it up to replace a defective regulator (cost $18 online) the internals were identical in every detail between the two alternators. Now I have a spare (the original) sitting on the shelf .
Addendum: The local auto-electric shop who specializes inrebuilding starters/alternators wanted $185 to "rebuild" my original Kubota alternator even when they agreed that all it needed was a new regulator. In my profession (retired from aircraft) anytime something is "rebuilt or overhauled" then ALL wear-parts are replaced, I.E., brushes, bearings, etc. are completely replaced and electronics (I.E. regulator, etc) are fully tested/recertified. It's my belief the automotive world merely replaces defective items and paints the unit for appearance. In other words, $18 did everything a "rebuild" would have accomplished for 1/10th the cost. Don't be afraid to dig into these things.... they're not airplanes.

Funny, I read the same thing a while back with a cheap $60 starter
being identical to OE, except this was for a JD. Machine lines and internals were identical.

I need one for one of my G5200s. $310 for OE, $120 for a Kubota rebuilt and the eBay special for $60.

Back to the original topic, Id say $144 for a lesson learned is a good deal. Could have been much worse obviously..

 

[torch]

That is not correct. The alternator output is regulated by the regulator (hence it's name) and when the battery is fully re-charged after engine start the regulator reduces the Field voltage which in-turn reduces the output of the alternator (and subsequently the alternator does not require as much energy from the engine.)

That is not always true. My B7100 has a permanent magnet rotor. The alternator produces a constant current (at any given rpm, of course) and the regulator limits voltage by dumping any current in excess of demand to ground. This is pretty common for small engines -- the 50A alternator one of my motorcycles is the same -- as it is cheap, simple and reliable. No brushes or commutator to wear out or gum up, and usually can make more current at low RPM compared to a variable field design of similar size.

I can't speak to the OP's alternator. It could well be a variable-field design such as you describe, and if it is then you are absolutely correct. I just want to make others aware that they need to know which type of design is in a particular vehicle when considering these things.

As for parasitic loads, assuming a variable-field system, an electric fan adds no parasitic load when not running, but a fan providing equivalent airflow to a mechanical design will actually draw suck more HP off the engine due to efficiency losses. Neither the alternator nor the electric fan motor are 100% efficient. Both generate some heat when working, which is wasted engine power.

While an automobile traveling down the road generates enough air-flow that the electric fan can be shut off most of the time, I suspect that a tractor trundling along doing work will require the fan at virtually all times.

 

[SDT]

I would not try to reattach a fan blade. Several years ago at a local demo derby a fan blade came loose and killed a spectator sitting in the bleachers. After that all fans were removed from all cars, that were entered into the derby. I realize that one was metal and yours is plastic. Just not worth the risk.

Agreed.

Repairing a cooling fan, whether composite or steel is a very bad idea.

More than one person has been killed by an ejected blade from an automotive fan, demo derby or otherwise.

SDT

 

[GeoHorn]

That is not always true. My B7100 has a permanent magnet rotor. The alternator produces a constant current (at any given rpm, of course) and the regulator limits voltage by dumping any current in excess of demand to ground. This is pretty common for small engines -- the 50A alternator one of my motorcycles is the same -- as it is cheap, simple and reliable. No brushes or commutator to wear out or gum up, and usually can make more current at low RPM compared to a variable field design of similar size.

I can't speak to the OP's alternator. It could well be a variable-field design such as you describe, and if it is then you are absolutely correct. I just want to make others aware that they need to know which type of design is in a particular vehicle when considering these things. ***8230;..

That's an excellent point...and almost always applies to brushless alternators (or in the case of many motorcycles/lawn-tractors and/or flywheel-magneto types, which also use the main battery as a capacitor/condenser to compensate for the lack of regulation)... however the common Kubota 40A alternator is a brush/field-regulated design.
Back to the damaged fan...if in a situation of necessity, some fan designs which use even number of blades can survive by removing the opposite blade to re-balance for operations until a new fan is found. If you do this, be sure to remove the blades completely, smoothly and leave no fractures.

 

[SidecarFlip]

Don't know what the output of the alternators on the M's are but I suspect more than a compact tractor, again, don't know and I've changed everything over to LED's on the tractor, everything but the feeble glow headlights

I changed out my high mount incandescent (sealed beam) worklights for 2 4000 lumen CREE x 9 LED lights forward and 2 3500 lumen CREE x 9 rears. The amber flashers front and rear are LED bulbs, so it the dome light and tail lights. Only thing not changed is the dash lights.

Reason I suspect my alternator is quite a bit larger is my tractors take Group 31 1100 CCA batteries which are pretty substantial but unlike the newer tractors, I have no power robbing electronics except the magnetic fuel cut solenoid. Everything is mechanical, well almost everything. the PTO light and the fuel tank sender are electrical.

I'd sure like to upgrade the feeble FEEBLE headlights but I cannot find a suitable replacement bulb, halogen or LED. The headlights are sad to say the least.

Maybe Wolfman knows the alternator output on the M9000 and 105X because I sure don't.

As an aside, the electric fan I put in front of the ac condenser to facilitate better heat transfer works quite well and I have it wired into the ac compressor relay so it only runs when the ac compressor cycles.

I've learned the Kubota ac in marginal at best when it's hot out and the sun is cooking you inside the cab. Every little improvement helps. I spend long days in the tractor in the summertime. Had the same deal with the 5030 HSTC I had before the M's.

I may be over drawing the electrical output of the alternator but I don't think I am. When I light everything up, I never notice any dimming in the dash lights and it never seems like the battery is anything but topped up.

 

[GeoHorn]

The little "B's" and "BX's" with a solid sheet-metal body are 14 Amp units. Most other Kubotas with a cast-aluminum open-frame alternator are 40 Amp units.... which can be replaced by the alternators most AirConditioned-cab Kubota tractors have standard, which are 60 Amp units. (All this according to my electric-shops data.)
If you want to see what the little 14Amp and the 40Amp units look like...here's the conversion article that illustrates both types: http://kubotabooks.com/AutoIndex/in...df&AutoIndex=51b545d41ed183bfd9b6fb3654c10cbe

 

[SidecarFlip]

Guess I have a 60 then. I'm pretty sure I can hang about anything on there I want to, so long as the sheaves line up.

I'm definitely retrofitting the 105 with an electric cooling fan this spring and I'm going to make it so it will push and pull (switched). That way I can blow chaff out of the radiator in the field.

Kind of wish I had a PTO dyno so I could gauge the power increase but I bet it's at east 10 ponies.

Europeans figured that out years ago. People here are a bit slow.

I imagine that my 105 also has a 60. Both have cabs and air conditioning. In fact the running specs are the same., just flywheel and pto power changes.

 

[GeoHorn]

...Europeans figured that out years ago. People here are a bit slow....

Europeans had the poop bombed out of their factories and equipment in the last Great War while we kept on keeping on with the same old stuff that was worn out making machines to bomb poop out of people. Result: They got newer technology stuff...we got the Rust Belt.

(Please don't let this turn political. I'm only stating historical info.)

 

[SidecarFlip]

I live in the rust belt and no problem with me. No water issues and no fire ants either.

We looked at a 300 acre ranch in Texas at one time but when I figured out that the land there is about 1/4 as productive as it is here, we passed.