Our 953C serial # 746 has a leaking pivot bar seal. Pulled it up on SIS and I didn't know the machine was equipped or partially equipped with waste handler parts. It appears the belly pan is as well. Anyway how do we replace the seal? It appears the outside cap comes off and gives access to the shaft and the seals? Any advice would be greatly appreciated!
That is the easy part. Removing the track frame (the pivot bar seal is on the inside) is slightly harder with hydraulic press tooling required. The track has to be split before starting.
Usually bad things going on when the pivot shaft seal is leaking Make sure you check ring on pivot shaft for pitting, shaft and bearings for wear and if you are a really lucky person check for broken bolts or worn plate on the retainer plate on the outside of the pivot shaft
Uggh. Thanks for the info Nige and PCM. Looks like this is a job for a professional shop. Our season is just getting started and I can't pull people out of the field to do repair work. I hate to ask - like what else? It's leaking on the inside if that makes a difference.
usually the pivot shaft is worn and bearings are bad There is only about a quart of oil in the pivot shaft cavity in the frame the seal is just a rubber donut that has pressure held on it by the thrust plate on end of pivot shaft
Kind what I figured. The OEM shaft is $3600 each..
A good machine shop could probably recover the existing shaft for way less than that.
years ago we used to weld them up and machine them Nige might be able to find info on salvaging the shaft I seem to remember a paper about that
Worst thing looking at the shaft is that they only install one way. You can't turn it 180 degress or swap shafts from side to side in order to present the bushing with an unworn surface on the part that is most heavily loaded. It appears that all BBX-prefix machines above S/N 00186 are so equipped. I have no idea as to the reason why although there was a Service Letter for the 3W-7551 Shaft that was used on tractors up to 186. I wonder if there were issues with it failing and as a result it was decided to use the 5Q-6023 (Custom Shop part) Waste Handlng pivot shaft to fix the problem.? Certainly it's been my experience the a Waste Handling Arrangement of any model generally has beefed-up undercarriage and/or powertrain parts. I'm surmising that the 5Q-6023 is just a beefed-up version of the 3W-7551. I can't see anything that gives specs or a procedure for the surface reconditioning a pivot shaft.
I was studying The 3w7551 goes back to at least a 953b I checked the roller frames on the c they are the same bbx1 to bbx2012 so I can't imagine they could be much beefier possible different material or finish I'll have to think on the repair directions
Same here. I was surprised to see the shaft and belly pan are from waste handler parts. Certainly not upset to find that out. Everything else on the loader seems to be non-WH spec'd.
Any idea on the man hours required per side?
That's almost a how long is a piece of string question. I would say it depends on a couple of things. First having all the necessary parts available before the job starts. Second how easy the tracks split and how much faffing has to be done to remove the E-Bar pin. You could even end up oxy-lancing it out. Everything else ought to be pretty straightforward provided all the necessary tooling is available.
Yes,as Nige says,those center pins can be more than a pig to get out. Thermal lance is often the last resort that has to play its face too often
Dumb question from a non-mechanic - Why not just fill it with grease and let it ride for a while?
I've gone through that type of reasoning. "How bad will it get, if I don't do anything?" Usually it gets worse. And more expensive. In a similar vein, we were recently on a job with my 120ton crane, a different companies 275ton crane, and a flown in work crew. City inspector came and slapped a stop work order on what the contractor was doing, with a potential $500 fine. Threatened to send the cops for any "non-compliance" , and the cops would write a ticket. Didn't take a lot of napkin math to determine the fine would be far cheaper than stopping work. Somehow, I don't think your track loader is going to fix itself, get to digging under your mattress. Mother Cat needs to keep its doors open too.
In the vernacular, "it's not going to magically heal itself if that's what you're asking."
Yeah I get that but it's 22 years old and this is the original seal so the shaft is probably worn on the bottom. The shaft will either have to be replaced or "rebuilt" by a machine shop. Lol - heard. Under no expectation it's going to heal itself just looking at an option to keep it in the field for a little while longer. If this doesn't make any sense I have a blazing sinus infection and I'm on cold medicine. Probably caught it in Vegas at Conexpo.
I'd expect the shaft can be metalized and turned down as long as it could fit in a lathe. My backhoe uses the infamous rotary swing cylinder. It was leaking out the bottom because the constant turning wore the shaft down. Don't even know if new was available but would cost a fortune if it was. The shaft is special because it has slots that the vanes bolt to. I was so relieved when the shop I took it to to repair said it could be metalized. They sent it to a specialty shop where they spray welded it with the appropriate hardness material and turned it down to size. It was about $330 if I recall and I think will last longer than the original. The top of the shaft was still in pretty good shape. The total parts and labour to R&R it unfortunately was about $3600. I think a replacement shaft would probably be double that or more.
Well,I see your point as it’s 22 years old. If you were only running it on occasion,it may well last you another few years with some grease slapped on so to speak. As for the cost to repair it further down the road,you may have long since finished your tip and have no use for it and simply sell it on through auction.
I am the primary operator and the machine has spent the last 6 years at our inert fill dump. It has racked up maybe 200 hours over that time. We found the leak when we swapped the D5 for it at the dump and brought the 953 to the yard for some TLC. Plan on keeping the machine if nothing more than I have an affection for track loaders and I bought it new. It's been a slow start to Q1 of 2026 so not wanting to rack up a huge repair bill on a support machine at the moment. If it needs a new shaft, which it probably will, probably looking at a $10-15K repair bill because we'll do both sides if we do one. I don't mind investing that in the machine since it has a basically new undercarriage on it and I have at least 10 more years of work for it. We aren't a heavy equipment repair business, we make our money moving dirt so the repair will be farmed out.
Sometimes it's just better to let someone with experience do the repair.