Reviving a G1900

[lmichael]

So, how many hours on that 1900 of yours again? Overall what kid of shape did you find that little alternator in? I opened mine up to add the tachometer tap to the windings but didn't feel the need to go into it all that far. My buddy has a brand new Delco alternator (back when I was a Cadillac tech in the late 60s/early 70s we weren't allowed to call them "alternators" we had to still call them "generators" per GM because since they were internally rectified they did output DC. Unlike Chrysler corp who IIRC copyrighted the name "alternator" because their units had external rectifiers, and preceded all the other companies.
I even remember their ad campaign from like 1958/59 showing the hood up on Chrysler and a bunch of guys standing around with electric shavers all running off the "alternator" with the engine "idling". Big things was then, a generator produced very low power at idle while Chrysler's "alternator" produced near full power at idle.
Anyway I digress: Just curious how the overall condition was. My 2160 just tripped over 1000 hours last summer. I'd love to have a "resettable" hour meter on it so I could actually "time" my service intervals rather than writing labels on my oil filter/air filter and so on

 

[Hugo Habicht]

D722 Generator Assembly

We push in the front bearing into the housing. If it has to be pressed in only apply force onto the outer ring. You can use the outer ring of the old bearing for a mandrel for pressing it in. Never hammer in a bearing, this will damage it and it will fail prematurely! Never press in the outer ring by applying force onto the inner ring or vice versa! This will also damage the bearing.

Put in the cover plate and tighten the four bolts.



Push in the stator (if removed), I had pushed mine out in order to be able to clean the housing. Make sure the orientation is the same as before, visible at the marks of the bolts holding it in and the wire position for the rectifier / regulator. Screw in the two standoff bolts holding the stator and tighten.



Press in the rear bearing onto the rotor, thin cover washer first, then bearing, then rear cover washer, flat side towards the bearing. Use a short piece of pipe as a mandrel. Again the warning: do not hammer onto the pipe / mandrel. The inertia of the outer ring will damage the bearing when applying hard hits!



Push rotor shaft into front bearing. Now put wavy spring washer (red, shown in housing) on top of the rear bearing and push the rear housing over the shaft / rotor / bearing.



Make sure the four stator wires are fed through the appropriate holes in the enclosure. Insert the two bolts and tighten and put the two nuts over the standoff bolts and tighten.



Feed the four stator wires through the small holes in the rectifier / regulator assembly and push down the rectifier carefully.



Push back the brushes (yellow) when they reach the slip ring in order to push the rectifier fully down.



Bend stator wires into nice loops again, wire going clockwise direction and insert and tighten four stator wire bolts (red) and regulator bolts (blue).



Put rear cover over the rectifier and insert and tighten the three ground contact bolts (red). Then push insulating plastic standoff (blue) over battery stud, nut (yellow) over the battery stud and tighten and spring washer and flange nut (green) onto the stud as well for later assembly of the battery cable.



Slide spacer ring and pulley over the shaft and tighten nut holding shaft on the hex end. Apply a new home brewed nameplate sticker if it was damaged when cleaning the housing parts and we have a fine fully rebuilt generator ready to go into the tractor.

 

[Hugo Habicht]

So, how many hours on that 1900 of yours again? Overall what kid of shape did you find that little alternator in?

The G1900 had 6045 hours on the clock when I collected it.



I have no experience with those Denso generators but judging from car generators I would find it hard to believe that it was still original. There is still about 25% left in the brushes and slip rings now, so considering easy access to the generator I left the old ones in and did not wait for the spare parts order.

With respect to "generator" versus "alternator" I believe both expressions are used concurrently. I prefer generator because I think it better describes what the thing is doing and I think this is also what Kubota uses in their manuals.

 

[Hugo Habicht]

Radiator

Did not want to do it at this stage but since the radiator was out already I did some corrosion removal on the side brackets, straightened all remaining bent cooling fins and sprayed the frame and top and bottom parts. Also sprayed the new drain plug. Should have left the nice brass maybe ...

Looks good now with the refurbished mounts.

 

[Hugo Habicht]

Seat mount

Corrosion was pretty bad here.



So everything taken apart. The loops holding the lever had to be bent open to get the lever out. Everything sandblasted, zinc electroplated and sprayed black.





Bonnet (hood) hinges

Also sand blasting and zinc electroplating here.





PTO brake

When taking off the brake pad to get the mechanism electroplated the pad cracked. No problem, just buy a new one, thankfully most parts are still available from Kubota.



162 quid for a 1 square inch size brake pad? I don't think so.

So made a new brake pad from brake lining material, made two rivets and riveted the brake pad on.



Done:

 

[lmichael]

Wow you are doing a number on that machine. So nice you saved that little "classic" from the scrap heap

 

[Russell King]

@Hugo Habicht are you doing your own electroplating or do you sent it out to a vendor?

Have you tried a product like this for rust removal?

https://www.amazon.com/Evapo-Rust-ER012-Super-Safe-Remover/dp/B00M0TLQ66/ref=sr_1_5?dib=eyJ2IjoiMSJ9.dXThK3FtMee5ZslkRJuRxarD2AvDevI4dIhXSrM62e74xfS76hfKkbVRa2LzIEYyMbEPhH3yAIqFaqxD3rwNzieNKUb2GRiQJwPFUrDVCkQWeFF2LyP3MX6PM_zALxjhSD55WQ01LvITFtRbNQjdE6t1kvlJqhCo9_-7dD79cBWgx5v4-iB502mk4qTjmMLcKOXXu09H8YW9he0IE_yd5IwNE3WWxXq8WMiecGmyXlsjnJpCaU7uPuSliarsavLDGN3YNIAcSts9k8L4XhYu6mHdb6ogqyOtuSXkv419P-gr5Mk-qpnLr4VJ5kHWquilL8h_YiUwVx6741s7GWjGiwNE3v1tW81k2j8TiYytelDiZoZ9gpme6Goo-maytmAPNGi1O35OM9GKWuntCrZ5suiuJbKcU9GwMmty-Nfl24BrI1UtbkqQ4-jaO7H6wHr_.6K418bMt2QUJlasWxcDL90ralJFXhlzaGvlEben8VDY&dib_tag=se&keywords=rust+remover&qid=1739150347&sr=8-5

 

[Hugo Habicht]

@Hugo Habicht are you doing your own electroplating or do you sent it out to a vendor?

For a few items or if I need them urgently I would do it myself but for bigger amounts, like here, I go to a company abroad. First three pictures is this batch of Kubota G1900 parts, the last picture is a bunch of car parts. A bigger amount of smaller parts can be done in a drum which is very cost effective. At home it's basically doing parts individually which is fairly time consuming.





Those are parts I did myself

Have you tried a product like this for rust removal?

Yes, I tried products like this in the past but what I do now is mechanical rust removal (sand blasting mainly) followed by chemical rust removal with phosphoric acid. The latter gives an iron phosphate passivation layer which is a weak rust protection already in case you spray the parts at a later date. In my humble opinion only mechanical or only chemical does not work long term.

 

[Hugo Habicht]

PTO clutch / belt tensioner / brake

Since the idler wheel halves were welded together after inserting the bearings I had milled out the welding spots in equidistant angles and I bolted together the two halves now.

My replacement bearings got lost in the post, so I did not want to wait for the new order and decided to reuse the old bearings which are still usable. With the possibility to take the halves apart it is easy to change the bearings now. I took the seal disks off, cleaned them out and put new grease in.





I also replaced the grease nipple. The thread size on all grease nipples on this tractor is M6x0.75. You can buy them from aftermarket suppliers at very little cost.

 

[Hugo Habicht]

Crankshaft seal D722 engine

When I took the flywheel off it was obvious that the front crankshaft seal was leaking for a while already.



I did not want to take the cover off, so I made a mandrel (aluminium ring, second from right) to press it in and a tapered bolt holder (left) for the crankshaft. Kubota seal ring 09560-00007 is very reasonably priced, no point looking elsewhere. Dimensions are 80mm outside, 63mm inside. M16 bolt (top) and round flat disk (right) from my collection of press tools.



First everything has to be cleaned.



Then I levered out the old seal ring with a screw driver. The surface area where the seal runs must not be scratched. Cleaned everything with acetone.



Now I attached the tapered plate to the crankshaft. Used M10x1.25 bolts with heads turned off to 16mm, so that they do not protrude into the seal ring. 5 holes on 22.4mm radius.



Seal ring with thin layer Elring Dirko-HT on the outside and molycote grease inside the ring. Slide over the tapered plate and crankshaft.



M16 bolt with nut, disk and mandrel for seal ring screwed in and tighten nut until seal ring is flush with the cover. I do not think there is an end stop in the cover, so you have to stop in time.



Wipe off excess Dirko sealant.



Attach flywheel. 56Nm and bolts oiled.



Attach pulleys (electroplated and painted).



Done.

 

[lmichael]

Love the attention to detail on the work you're doing. Really nice!

 

[Pete O]

You're doing an amazing restoration job on that machine. I totally understand the urge to do a not-economically-viable restoration project, I did a similar thing with my old Ford tractor a few years ago.
I have a G1900S that I bought from a machinery auction when we bought our property 25 years ago. It had 2000hrs on it, was missing half of the PTO driveshaft to the deck, apparently lost during transport. I bought the machine and had the propshaft rebuilt for about the same total money as a consumer-grade mower. What a machine! I mow about 2 acres of lawn. I eventually got a burnt-out exhaust valve seat and no repairer would touch the cylinder head so I bought a low-hour import motor, then years later I spotted a new-old-stock 48" deck from a different model that I bought and modified to replace my flogged-out deck.
Sadly after about 22 years the Kubota just got too tired to keep as a main mower so I bought a mega-dollar Cub Cadet and put the Kubota into semi-retirement, it now does duty such as towing a weed sprayer or a plastic garden trailer. Going from the G1900 to the CC I liken to getting out of a clapped-out old Rolls Royce into a brand new Hyundai.
I've just posted a query that you might be able to assist with re the lost transaxle dipstick on my machine- I plan to make a replacement but need the length.

 

[Hugo Habicht]

Hi Pete,

I totally understand the urge to do a not-economically-viable restoration project, I did a similar thing with my old Ford tractor a few years ago.

A bit mad, isn't it? Glad I'm not alone

I eventually got a burnt-out exhaust valve seat and no repairer would touch the cylinder head so I bought a low-hour import motor, ...

How many hours has your G1900 now?


That reminds me to check the valve play, it's on my long to-do-list, maybe I should move that item up the list. I have to read up how often it has to be checked and how to adjust it. Plenty of cylinder heads and rebuild kits on the market, I will propably buy them and put them in storage. So I am not too worried about the engine, gear box is the big unknown.

Sadly after about 22 years the Kubota just got too tired to keep as a main mower so I bought a mega-dollar Cub Cadet and put the Kubota into semi-retirement, it now does duty such as towing a weed sprayer or a plastic garden trailer. Going from the G1900 to the CC I liken to getting out of a clapped-out old Rolls Royce into a brand new Hyundai.

Ahhh, poor swap , I would have fixed the Rolls Royce and drive in that.

Lack of maintenance is the problem on my G1900, using a grease gun as per operators manual would have made a huge difference. But a few bearings and bushings are cheap, just a bit of work.

Kind regards,
Hugo

 

[Hugo Habicht]

Dashboard (Visor)

The dashboard cover had faded a bit, the symbols were partly missing and there were deep grooves in the top from the bonnet (hood) scraping along due to the missing rubber bumper on the radiator. Also it had broken almost all around the starter switch.



I cleaned everything thoroughly, straightened the broken out starter switch part, glued butyl tape on the top to prevent resin seeping through, roughened up the inside with coarse sandpaper and laminated two layers of fiberglass mat using two pack epoxy resin.



I filled the grooves with epoxy resin and gave it a thin coat of semi gloss black paint. Then I repainted the symbols with a very fine brush.



Looks acceptable again.

 

[lmichael]

I have to talk to my son in law and see if he could 3D print me a nice panel

 

[Hugo Habicht]

I have to talk to my son in law and see if he could 3D print me a nice panel

You can always make a wooden one (or other material if you like), then make a plaster cast mold and then laminate it with fiberglass and epoxy resin. The old fashioned way before 3D printing was invented. Also much stronger than 3D print.

 

[Hugo Habicht]

Did not feel like doing my tax return today so I went into the workshop and made a replacement for the nut holding the starter switch. The original one had pitting, the usual problem with zinc die cast parts, so I used brass. Made two while I was at it. Sending them out to get them chrome plated tomorrow. Thread size is M20x1.

 

[lmichael]

Might look cool leaving them brass and simply clear coating them

 

[Hugo Habicht]

Do you know a clear coat that sticks to polished brass and that lasts and does not yellow over time? So far I have not been successful finding one.

 

[22R]

I honestly am little clueless on that. The story of my G2160 is a little comical. My first foray into garden tractors was with an old Allis Chalmers B10. All beat to hell, blown head gasket, bad rod knock, burning enough oil to not see the tractor when it was running. I did a full teardown of it to the frame. Ended up replacing the engine with a brand new cast iron B&S Commercial 16 hp single cyl. Rebuilt the PTOs, steering, electrical system, mower deck. Sanded and repainted it from the frame out. Back when I had the S/N the local dealer told me they believed it was between a 61-64. I ended up selling it and all the accessories I'd accumulated (snow blower, plow blade, belly grader, rototiller, various hitches and such.
But at that time I was exposed to a Kubota and just loved that little diesel and it's "sound". Swore someday I had to get one. Well, time goes on, I'd had the AC for about 30 years and found parts to rebuild the mower deck were nearly non-existent. So, I sold it and ended up with a smaller but pretty cool Honda 4514. Little 2 banger water cooled and it ran like well "a Honda" smooth, quiet, fuel sipper. Honestly all the machine I really needed.
But, a few years ago, perusing FB Marketplace, I see an ad for this G2160 with the magic words "diesel engine". After some cajoling wife said go look at it. It was a little beat up but low hours, good engine, and bones. So, wife allowed me to buy it. Seller even knocked off $200 and delivered it to my front door from close to 90 miles away.
Wasn't without need of plenty of work. Faded paint, headlights, non working power steering, messed up electrical system, filthy cooling system, mouse nests.
I got some things repaired right away. Power steering right off. Which wife appreciated, because when my allergies act up and kick in my COPD, she gets pressed into service.
In the end I did a partial restoration on it, (repaint, used brush on bed liner in place of rubber mat, lots of other things. Mods to electrical system as well, retrofitted very bright LED headlights inside the original housings which I polished.
Bottom line I have my Kubota and a nice machine. A bit too much with the 60" deck (would love to trade someone for the 54"). But, it is a nice machine. And my oldest granddaughter LOVES it. Taken this past October. She's 3 1/2 and wears her papa out. Her little sis hasn't warmed up to it yet
View attachment 147832 View attachment 147833 View attachment 147834

Is that seat stock OEM? I have tried to find a direct replacement with armrest for my G1900 but due to the offset mount pattern I cannot locate one.
Nice looking machine too btw. I do not have grandkids but my daughters Golden Doodle loves riding in the cart behind my Kubota

22R