B7100 front knuckle/final drive/portal broken

[2drx4]

I'm not sure what this is specifically referred to on a tractor. I'd call it a portal if it was on a truck. Anyways, it's broken, see pictures. I discovered it when I pulled the drain plug and realized it was filled with grease, and then started to ask the question of why that was. Cleaning up some of the schmoo around it determined that it's cracked and epoxied, and a gooder of a crack at that.

My initial plan was to pull it off and weld it, but I already found a used one, so I'm hoping the used one isn't in worse shape than this.

What other parts will I need when I swap it over? I'm going to assume the gears are not damaged too badly from being run in grease, if they are I will cross that bridge when I get there. I'd like to order parts now so I can tackle this when I'm back in town, as I regularly leave for long periods.

Out of this diagram:

I believe I need the #24 o-rings that seal the kingpins, and possibly the #17 gasket (or is it reusable???), and should I just do the #13 dust seal and #25 "packing cushion" (I believe the felt that goes around the knuckle ball) at the same time?

I think I just need the #9 seal from this one, but since it's been running in grease for god knows how long I might try to order the bearings # 10,11,16,17. My "new" portal appears to be stripped of all parts, but I can move my stop bolts/plugs/etc over from the old one.

Is there anything else I should need? Should I do anything else while I'm in here? Thanks for any help.

 

[PaulL]

I wouldn't have thought running in grease would cause major issues, it's still a lubricant. It's more that whatever was supposed to have the grease probably didn't any more, that's more likely to be the part that's damaged. The bearings I presume?

 

[2drx4]

I wouldn't have thought running in grease would cause major issues, it's still a lubricant. It's more that whatever was supposed to have the grease probably didn't any more, that's more likely to be the part that's damaged. The bearings I presume?

It currently is still working fine and I have no idea how long ago this happened. The previous owner knew nothing about the tractor other than some basic info, used it for snowblowing and that was it. He may have changed the oil in the engine a few times, but otherwise didn't seem to have performed any maintenance. Inside the operator's manual there is some notes from 20 years ago, one indicates that a hub/portal gear was broken and replaced. I could see this damage having occurred at the same time, but I would question why you would not replace this part at the same time, as it was likely available then. Cost would be the only reason I could think of. I do not think grease would lubricate the bearings adequately long term, hence leaning towards ordering them at the same time. I don't know how much grease was in it, it was not full, and I am not sure how they greased it or the last time they did. I at least put a grease nipple in place of the previous fill plug and purged it out the drain.

 

[PaulL]

Ah. Are you saying that the fluid (UDT or gear oil) was all gone, and had grease instead? If so, that's not so good. Whereas if it had both grease and fluid, that doesn't seem as concerning.

 

[2drx4]

Ah. Are you saying that the fluid (UDT or gear oil) was all gone, and had grease instead? If so, that's not so good. Whereas if it had both grease and fluid, that doesn't seem as concerning.

Yes, no oil, just grease. The "repair" to the broken casting was not oil tight, not even close. I believe they attempted to fill it with grease instead, but I'm not even sure how they did that. At least with a zerk on it I could pump quite a bit in.

So yes, not good.

 

[rbargeron]

Looks like someone did a quick clever fix on an expensive broken part. It has lasted fine this long so I'd pack or inject a bit more grease in there and close it back up with silicone adhesive sealant. The axle gears will be ok submerged in grease instead of oil. They may only last fifty years instead of a hundred.

 

[2drx4]

Looks like someone did a quick clever fix on an expensive broken part. It has lasted fine this long so I'd pack or inject a bit more grease in there and close it back up with silicone adhesive sealant. The axle gears will be ok submerged in grease instead of oil. They may only last fifty years instead of a hundred.

I already ordered the part, so I am fixing it. I could have just TIG'd that back up too and put new threads in it, but for what it cost for a used portal housing I decided not to bother. The part was not expensive. Being hack is fine when you either have no tools, time, or money to do it right, but I've certainly at least got the tools or money.

There was still oil in the differential and the other portal, so they will be okay. I'm more concerned that there seemed to be very little grease in this one, and I have no idea how long it was like that.

 

[rbargeron]

Glad you found a part - another older machine returns to full duty ! Good doing !