Trouble disengaging front axle

5030 · Nov 19, 2023

I do believe the front drive unit in the gearcase, power is transmitted by straight cut gears which can sometimes be a PITA to disengage, depending on if there is any imposed by the front axle load on them. To be sure, I'd have to get out the shop manual and look and the shop manual is out in the shop presently so I'm venturing just a guess.

mcarlile · Nov 19, 2023

I want to thank everyone for their comments. I'll be trying some of the things that were said and I will post on the forum if I come up with a solution. Thank you again.

rScotty · Nov 20, 2023

5030 said:
Scotty... Keep in mind that Kubota employs a short coupling that is retained by a single roll pin between the output shaft and the input shaft on all FWA units and that is the failure point and is designed to be.

That coupling is just plain (not heat treated) steel and eventually the internal splines (that engage the shafts) wear out and it must be replaced and a good indicator of wear is the noise it produces as the internal soft splines jump over the heat treated ones on the shafts.

I just replaced one on one of my M9's a couple weeks ago and that part is readily available at your friendly (hopefully so) Kubota dealer and it comes with a new roll pin as well for the paltry sum of 52 bucks.

Easy to replace as well. Just remove the machine screws that retain the outer covers, slide one cover over the other to expose the 'sacrificial' coupling, drive the roll pin out with a suitable sized punch, and install the new one and add a bit of grease to the internal splines before installing.

5030, I will keep that in mind. Good post, BTW.

I will remember, because now that you mention that spline coupling, it I have seen them worn now on a couple of tractors and wondered about the cause. I thought it was lack of lube, and believe that is a common enough thought that there have been posts about better ways to grease and seal that joint.

Bit apparently I hadn't thought it through far enough. Lube is good, but your explanation is better.
In fact, with so many owners determined to treat their "part time 4wd" like it was a "full time 4wd", designing a sacrificial part to protect expensive tranny & axle parts makes good sense. Maybe Kubota should advertise it.

Very clever. Good thinking, Kubota.
rScotty

5030 · Nov 20, 2023

Very easy to replace as well. Takes about 10 minutes start to finish, too bad the part cost is 50 bucks for a simple splined soft steel coupling but then today, everything is costing a lot more than say 5 years ago.

I need to rebuild the loader on my OS M9 as It's getting sloppy and there is a ton of lateral movement in the linkages which is probably due to the previous owner's lack of timely greasing and that is pretty typical today.

I had sticker shock when I ordered up just one set of linkage components (there are 8 of them on every loader) plus 4 fulcrum pins. My cost on just 2 of them was $504 bucks and all I really wanted was to 'borrow' a set so I could plot them and cut them on our CNC plasma table and I'll machine my own fulcrum pins. Needless to say, I about had a coronary when I saw the invoice and best part is, I can return them to Kubota but there will be a 100 buck restocking fee, so I guess that it is costing me 100 bucks just to plot them and return them. Oh well

I needed to have a new set so I can plot the centerlines of the pin bosses as mine are basically shot. I'll probably cut numerous sets and sell them online as I bet there are more than a few owners out there in fantasy land with worn out linkages, but I will have to machine the inner bosses from bar stock and weld them on no matter what and the welded on bosses determine the side clearance between the linkages and the loader frame.

I'm going to re-engineer the fulcrum pins and get rid of the recessed grease fittings as well. I find them to be nothing but dirt collectors and a PITA to inject grease into. Hopefully, all that is worn out are the linkages and not the loader frame through holes but I won't find that out until I take it apart in the spring. If the loader frame bores are ovaled out, I'll have to line bore them oversize and press fit in new steel bushings or machine them out of 660 CA Bronze bar stock, I'll cross that bridge when I get there as I have no idea at this point in time.

All I know is, the loader is extremely sloppy, especially when curling the bucket and I'm getting concerned about failure when I'm loading round bales on trucks.

5030 · Nov 20, 2023

rScotty said:
I thought it was lack of lube, and believe that is a common enough thought that there have been posts about better ways to grease and seal that joint.

No, coupling wear is all about running a unit in FWA on dry pavement or packed hard dirt constantly. None of them (no matter what brand it is) are designed to run in FWA constantly. FWA should only be used when absolutely necessary as predicated by the job. In the workshop manual, Kubota suggests greasing the sacrificial spline coupler when replacing it, I presume there is a bit of back and forth movement between the output shaft and the input shaft.

Myself, I rarely use FWA on my tractors, only if I need the added tractive effort for a particular job. Besides, running in FWA causes accelerated front tire wear and a new set of shoes on my tractors is now in the excess of 5 grand. You just cannot replace the worn fronts with new shoes and not replace the worn rears because it throws off the lead-lag ratio and that causes undue strain on the driveline in itself and guess what, that soft splined coupling wears out that much faster.

I don't believe that most owners of FWA tractors really understand the lead-lag concept and how it can very adversely impact the longevity of a unit.

Same thing applies to a full time 'four wheel drive truck or car (AWD). You have to match tire diameters or you will have driveline issues.

DGF · Dec 18, 2023

mcarlile said:
I own a 2015 Kubota M6060 with FEL. Using the FEL, I need assistance from the front axle from time to time. When I want to disengage the axle it will not disengage. I have tried backing the tractor up, lifting the front end off the ground and spinning tires backwards and rocking the axle back and forth by hand to no avail.
My question, has anyone experienced this problem and how did you fix it.
I can eventually get the axle to free up and disengage but for what ever the reason this happens every time. I have had Kubota service to look into this problem without a permanent solution.

Like others have said it sounds like a pressure problem that doesn't necessarily release when you back up or turn the wheels. Try just tapping the peddle forward and/or back without moving the tractor. Just a tap is enough and it should free up. When there is too much pressure the control handle seems to be jammed and if it is this is a sure sign of there being pressure on the gears. If tapping doesn't work make sure the peddle has a valid neutral position. It could be that the peddle biased forward or backward just enough to keep some pressure applied. It would not take much.