40XT Wheel Hub

[FrostyLBZ]

Howdy, got myself in a little bit of a pickle, said I'd help my elderly neighbor with his skid steer. I work as a HD truck mechanic and have worked on a skid steer or 2 but nothing all that in depth. That being said, he's got a 40xt that **** out a front left wheel seal, and its slinging oil/leaving a puddle. Checked out some videos on the subject as i've never pulled a skidsteer axle assembly out before and got some useful information but I still got a few things I need to know before attempting this.

Firstly, what holds bearing pre load in the hub? I assume its the big drive sprocket that gets bolted on the end of the axle and sits in the chaincase but again, never had one apart and from what i've seen this is gonna be a press together project.

Secondly, if that sprocket is in fact what's setting the bearing pre load, what is the torque spec for the bolt/tightening procedure? Does anyone use any loctite on the bolt or is there some sort of lock tab the video I watched glossed over?

Third, I suspect the drive motor is leaking hydraulic oil into the chain case, is there any tricks to confirm this other than just watching it with the cover off running it back and fourth?

Id really appreciate some insite on this, I obviously don't have a service manual for it otherwise id just read up on it. Thanks in advance.

 

[Gearclash]

Did wheel bearings on one corner of a 420 quite a few years ago. As I recall, the bearings are retained by the drive sprocket nut. The sprocket is pulled against a shoulder so the bearing preload is a fixed dimension. The nut tightness does not affect preload. I thought that was a goofy way to set the bearings but it seems to work. Pretty sure the retaining nut is a castle nut with a cotter pin retainer.

Best way to determine whether the motors are leaking is to drain the chain case and refill to spec, then check after some time (100 or 500 hours use) and see if the oil level is now significantly higher.