Front right tire clunk and lock up

[reco31]

Hello everyone, looking for assistance please. Was out baling this afternoon when the tractor seemed like it was under some abnormal load or resistance (not from the baler) and then the right front tire locked up and then let loose with a loud bang. That was the end of baling, I brought her home with a few more clunks from the right side along the way and locked up once more. I was in 2 wheel drive and it's an '88 7745 4x4. I haven't looked at it yet, just switched tractors and kept baling. Any thoughts would be greatly appreciated.

Thanks in advance

 

[Renze]

That means hub damage. Had it once on a 5245 but that is the light axle, yours is the heavy.

Before we blame the hub internals, does it happen straight or when steering ? If the U joint yoke is bent too wide similar effects show.

 

[reco31]

Thanks for the reply, going in a straight line in 2 wheel drive is when it started. So I think I start by removing the "hub cap" held on by 3 flat head bolts? There is also 12 bolts around the outside of the rim?

 

[Renze]

As far as i can remember from the parts manual , you should get the input shaft bearing behind the cap and able to inspect the satellite gears after removing the cap with 12 (or so) bolts.

Jack it up because the actual wheel bearing will have no support with all those bolts undone.

 

[brenten5]

Almost bet it being the bearing, the race in the bearing will have buggered up and the clunking is the balls shifting around and grabbing on each other, if you look at your hub compared to the axle it probably won't be square and maybe rubbing

 

[reco31]

Yeah got the hub off and disassembled, big inner bearing has completely, and I mean completely failed and 4 or 5 rollers have disappeared, crunch crunch. Thankfully everything else looks fine, but I will be changing both bearings and seals obviously. Planetary gear looks fine.

 

[Renze]

Then youre Lucky. The light duty axle has the driveshaft seated in needle bearings. With a failing shaft seal, dirt enters this bearing with no connection to "open water" so all crap would stick in this sensitive bearing.

The wheel bearings are 20cm diameter ball bearings that still rolled even with the driveshafts wallowing out the needle bearing bore untill the pinion was so misaligned that a single tooth would touch two ring gear teeth. It really is an economy axle, not great for a heavy loader.

The UR1 planetary axle like yours, is HD though

 

[reco31]

Got her all back together and running smooth as ice. It even holds oil now.