MX5800 4wd

[coolbrze]

I've noticed that when I have a heavy load in my MX5800 grapple & I'm reversing uphill in 4wd that my front tires don't spin & lightly click like somethings not engaging. Is this a safety override so I don't blow the front axle or something since there's so much weight on it or is something messed up? 4wd works fine all other times...

 

[sea2summit]

You never want to back up a hill with a heavy load in the FEL. That moves all the weight forward on those axles and reduces the affects of any counterweight. If all that weight is on them and if they’re spinning you’re gonna break something in a hurry. The front axle is the weak point of a tractor.

Clicking noises would need more looking to tell for sure. Could be differential up front, bevel gear, guess best case is you might only have damaged a bearing. Just because you don’t notice it somewhere else doesn’t mean there’s no damage it’s just not slipping enough to hear when it’s not under strain.

 

[ptsg]

No safety override. There is something giving up somewhere in the front axle. Most likely the splined sleeves on the driveshaft from the transmission housing to the front axle.

It either stripped the splines on the sleeves or the roll pin just slipped out, allowing the sleeve to move and disengage from the splines.

Splined sleeve/coupler - #010
Roll pin - #030

 

[sea2summit]

Easiest way to trouble shoot is going to be getting the front wheels off the ground with the tractor off and see what happens when you spin a tire. It will become pretty obvious pretty quick if any of the above is the issue.

 

[5030]

No safety override. There is something giving up somewhere in the front axle. Most likely the splined sleeves on the driveshaft from the transmission housing to the front axle.

It either stripped the splines on the sleeves or the roll pin just slipped out, allowing the sleeve to move and disengage from the splines.

Splined sleeve/coupler - #010
Roll pin - #030

View attachment 789861

Actually, that is considered a consumable item on a Kubota FWA tractor. I've replaced mine more than once. The coupler is made softer than the drive shaft so the coupler(s) fail and not the shaft. Easy to replace and not all that expensive. Typically, a failing coupler will exhibit a clicking sound under load. Easy repair too. Last ones I bought were 50 bucks or so each with roll pins included.' Just another good reason not to run in FWA unless absolutely necessary.

 

[ptsg]

Actually, that is considered a consumable item on a Kubota FWA tractor. I've replaced mine more than once. The coupler is made softer than the drive shaft so the coupler(s) fail and not the shaft. Easy to replace and not all that expensive. Typically, a failing coupler will exhibit a clicking sound under load. Easy repair too. Last ones I bought were 50 bucks or so each with roll pins included.' Just another good reason not to run in FWA unless absolutely necessary.

I had to replace it too on a Kubota B7000. On that tractor, they still used an U joint since it's not a straight shot from the transmission to the front axle like the newer ones. Cost me €95 at the time and it was a royal pain to find the part.

Mine started clicking when I noticed and also broke the roll pin in two pieces and sent them through the cover, poking holes all over it. Granted the cover was paper thin but ended up fabricating a new one with thicker material.

A bit hard to see but it's still possible to see the splines wore out on the left coupler.

 

[5030]

Both mine are straight shafted, glad of that and yes the cover is thin on mine as well though I've never had the roll pin migrate.