Lost 4WD L2850DT, ideas?

[Eastinlet]

1988 diesel 4WD, standard 2x4 transmission and shuttle shift. Been a great tractor, no problems until now and who knows how many thousand hours on it.

Never heard a sound, went to disk a field and she was no longer there. Diff lock works fine but does not provide adequate traction for the work, so I am stalled until we can get the 4WD repaired.

Linkages are fine.

Took the propeller shaft off last night... couplings are fine and shaft is not broken. Problem is in the back end, not the front.

Drained the oil and took what Kubota call the "front wheel drive case" off. Can see no problem with shafts or other internals. The forks we can see appear to function fine.

My buddy (transmission man) is helping, he sees a loose (on the shaft as in maybe a broken key?) gear back in further, but parts are not matching exactly to the parts manual I downloaded yesterday. So far unable to figure how to get any shafts out of the transmission short of breaking everything apart?

Any ideas or diagnostic help would be useful and much appreciated.

Also, does anyone have the service manual for this tractor... be willing to copy a few pages appropriate to this repair?

Or advice on where to get a less expensive service manual? Checking around they seem to want over $100 and closer to $200 for this, seems a little salty to me but I am probably out of touch with pricing.

Thanks in advance for any assistance.

 

[rbargeron]

If I'm not mistaken that tractor was available with and without mid pto, with dual or single dry clutch, even with wet clutch. Having the right parts list for it is pretty important to figuring out what connects to what.

The gears inside Kubotas slide on splines or on smooth bushings - no keys to break. Taking a shaft out can be a project - but at least all the shafts have splined couplings at the end of each gearcase.

The little bent pin that shifts fwd in and out (010 on the diagram) can break or jump the groove - but you probably already checked that. The fwd gear is driven by a gear directly above it - with the engine off & trans in gear, that gear should not be free to turn. Jack up one rear wheel and roll it to see what's turning. You'll find the problem.

 

[Eastinlet]

THanks very much for the advice, lbargeron. Did not know this model had the options you mentioned. This one has no mid-pto but do not know about the clutch. Maybe I can run the serial number by a dealer and see if they can help.

Will jack up a rear wheel tomorrow as you suggest.

The gear above that you mentioned turns freely when in gear, it does not appear to be attached to shaft by splines. That does not seem intuitive to me. Does that free turning mean anything to you?

Is the .pdf diagram you attached from an L2850? It has different part numbers than mine.

I'll report back with what we find. Starting to turn into a job. Any advice welcome.

 

[rbargeron]

When you are checking on what turns in there, make sure your range selector is in high or low (not neutral).

Yes, a free turning gear usually has a drive collar next to it and another gear (bigger or smaller) next to that. The collar can engage either gear (leaving the other free to spin).

The diagrams I have are from a parts list for an L3450 - made around the same time period and should be similar (no guarantees). If you look while somebody turns the tire and shifts the levers, maybe things will clear up. It's technically possible a gear broke in half and fell down out of the way without jamming anything - but that's extremely unlikely.

This diagram shows the hi-lo drive collar 150 engages either gear 100 or gear 110. Gear 190 is splined to the shaft that's the main drive to the rear differential. Gear 190 or one like it is the one that engages the gear down in the fwd box. Your rig may not be identical - but it should be similar.

 

[J252]

Look again at the pdf that RBargeron "fwd shift.pdf" posted a few posts up^^

Though different, the mechanical setup in that pdf looks similar to our old L345DT. In my case the tip of the shifting shaft (indicated as part 010) wore down and eventually broke off, so it could no longer hold the gear (which slides on splined shaft) in the 4wd position.

 

[Singlemalt]

Messick's | Dealer for New Holland, Case IH, Kubota, Cub Cadet and More | Online Parts, Sales & Service.

These guys have a section under Kubota parts diagram that lets you select your tractor and they email the section requested.

They would also be happy to supply any parts that might be needed.

 

[Eastinlet]

Thanks for the diagrams and advice.

Had no time to work on the old girl today, but did get her jacked up on one side to turn a wheel. Kind of a problem because I had no helpers today so I could not see the gears. Far greater problem is that I am unable to turn the wheel at all... tractor in gear as is hi-lo range. I am unable to turn it, will try with another guy. May have to arrange some leverage to rotate it. Have turf tires, no ag tire lugs to grab onto.

What I am seeing does not seem to jive with the recent schematic Rbargeron sent. I will take a photo tomorrow. I am seeing a gear above that has a smaller gear both fore and aft of it, both of the smaller nearly touching the larger central (presumably the driver for 4wd) gear. This larger gear spins freely but the neighboring gears do not move. Unable to see whether the shaft is splined because the gears are close together.

Have got to turn a wheel to see what moves in there.

I broke down and bought a service manual from Messick's yesterday... not cheap but can't afford not to. Be handy to have around for future repairs since I plan to keep her running for a few more decades. Also is a resource to help others with.

I may not be reading the the latest 3450 schematic right... and thanks so much for sending it... but I will study this some more and attach a photo tomorrow. Perhaps we can get this figured out yet.

 

[rbargeron]

Sorry - I'm used to wet clutch machines. If the tire won't turn, it's trying to turn the engine too. Don't force it - the engine might start! This means your tractor doesn't have the wet clutch and the trans needs to be in neutral to roll the tire by hand.

The gear that drives the bottom fwd gear is actually an "idler". It turns on its shaft but isn't driven by it. It's driven by another gear further up on the main pinion drive shaft. This stuff is hard to visualize without a cutaway drawing - which the WSM usually includes.

 

[art]

After the DT part there is a number, that will allow someone to tell you how the tractor is equipped for transmissions and PTO.

 

[Eastinlet]

@ J252: Yeah, had checked that before by flashlight but took a closer look today. The shaft and groove are in good shape, no visible wear which is amazing considering the hours. Linkages are good as well, the problem is definitely internal and starting to think in the back end. Trying to confirm that.

@ Singlemalt: Good idea, especially in light of what I learned looking at the serial number today, see below.

@ Art: I have never looked at that number in years but did today. Feeling a little stupid as it is an L2850D NOT DT. Dunno where I got the DT in my head, but it was planted so firmly that I ordered a manual on that solid foundation without ever checking. Too soon old and too late smart. Unfortunately there is no number following "L2850D 50898". I would appreciate if you have any information to share about what I've got. Best I know is it is about an 1988, know nothing about the clutch type etc. Guy before me wore out a backhoe on it but barely turned a tire except to plow snow.

Right now can say with certainty that the issue is not linkage or shifting shaft.

All contents of the front wheel drive case look fine and operate properly.

Can say that it does not APPEAR to be front end ring/pinion engagement, rbargeron suggested that as a possibility to be ruled out before getting into difficult transmission dissassembly. Have not done a visual inside front pumpkin, but manually turning the front wheels turned the propeller shaft back to the front wheel drive case. Can I assume that rules out ring/pinion engagement issue? Could they maybe slip under power but not using gentle manual turning? I hear no gear grinding under power, in fact no sounds at all.

If the front end checks out and the propeller shaft, linkages and internals of the front wheel drive case are all ok... then we're going to need to start on the back end. All advice and diagnostic tips are welcome. Thanks for all the help so far, appreciate it.