Severe Use

JimMorrissey · Apr 5, 2006

I'm wondering about the long term effects of overloading a loader and/or a backhoe. Relative to the size of the machine, how many "show stopping" boulders can a person attempt to move before a machine begins to breakdown prematurely? I'm not talking about lack of maintenace here (no grease or oil changes/filters) or deliberately pounding on a machine such as trying to move a rock by ramming it with the loader bucket. I'm thinking of daily operations with some brain activity. At what point will loads to the absolute max capacity do permanent damage to the hydraulic system....In other words, at what point does one cross the line from use to abuse? There is not a lot of discussion about this in the manuals.

**In this situation the fuel is fresh, the fluids and filters are changed and the joints are well greased.

Dmace · Apr 5, 2006

The maximum load capacity that tractor companies list is not the maximum that the loader will lift. I am sure they factor in a good 20-25% safety factor that will ensure you don't over work the hydraulics or the loader design itself. Designing a loader that will lift 1500lbs max and limiting it's use to 1100lbs will ensure a longer life expectancy. IMO

SteveM · Apr 5, 2006

Really good question, I would bet the mechanics at a big shop could tell you where the weak links are in any given machine...if you are simply lifting too much it could be hydraulics etc, but if it is a situation of bouncing with too much load it could end up cracking/bending something structural - I have seen an old kubota broken in half near the bell housing once, wickedly overloaded and abused for years... /forums/images/graemlins/shocked.gif

JerryG · Apr 5, 2006

Jim,
I think that the first problem that you will encounter will be cracks. There will also be loose bolts. The bolts that connect the loader to the tractor will start backing out and will need to be check more often. You will give the relief valve a good workout. Over time the valve will have to be changed.

Spiffy · Apr 5, 2006

Great Topic!!!

Ironically, I was just mentioning in another thread how I remember continously lugging 25HP farm tractors, but know the same treatment would be detrimental to my 45HP PT (which I consider quite well built in the world of CUTs).

As far as pumps and engines, not only how hard you run them. but the longer you run them at challenging conditions the more wear will incure, because you'll be thinning the oil (maybe even to the point of lubricant breakdown, also can cause cavitation in pumps) also, as a rule of thumb the higher the temps (yes very cold is bad too) the quicker bearings and other components wear (in the case of pistons etc, don't forget the thermal expansion changing piston shape, also lugging can exagerate blowby making lubrication even more difficult). What I'm saying is that demanding 60 seconds of maximum output on a machine that just got up to operating temp, could be less detrimental on an engine or pump than running 2/3 that output for an hour.

On cylinders, I'm thinking is mostly the one ill fated moment for an actual rod failure; but every force that really strains it or applies lateral force will be a little more wear on the seals.

Low speed bearing and bushings, I'd say the same; you can perhaps find a force that will destroy them, but consistant loads at 20% more than "target" might push the life to half (I pulled those numbers out of thin air, but I do know there are charts on that from many bearing mfgs).

OK, now that I've rambled; let's hear what the experts have to say! /forums/images/graemlins/blush.gif /forums/images/graemlins/grin.gif

edit: also as you mentioned, and I think Jerry referenced; machines don't like impacts (but we're all guilty on occasion). There's a reason construction equipment weighs 10times what it would need to, to just "operate" a given attachment.

scott_vt · Apr 5, 2006

Mornin Jim,
Ive always had a, kind of seat pants sensation, when I knew I was abusing a product, whether tractor or otherwise! That probablly doesnt answer your question unfortunately!

I would have to say, in refering to a tractor and associated hydraulics, is that the machine is being abused when you begin getting premature failures on mechanical and hydraulic systems in relation to the hours on the machine.

In other words, when you go to the dealer and need a new hydraulic pump, and the dealer says how many hours did you say you have on that machine? /forums/images/graemlins/confused.gif

scotty

_RaT_ · Apr 5, 2006

I'd agree with you Spiffy. I can't speak for all the compacts, but with New Holland and Kubota I have had, noticed substantial wear at all loader pivots, particularly at the 4 link bucket locations. I do grease more frequently especially when I spotted how quickly it was happening on my Kubota L48. I do not believe any of the compacts are designed to take the "severe" use at least not to the level of the industrials. I have talked to several dealers who suggested having someone else with industrial equipment do the large work as it is simply to hard on compact equipment. That was Steve Carver and my local dealer. After having several tractors, I concour. Its one of the reasons I would be very cautious purchasing a used backhoe where the many pivots that take high stresses at the pivots purely from the leverage aspect and placement of the hydraulic cylinders. I suggest you take it easy and grease often.

BadDog · Apr 5, 2006

This is a really tough question since different people have different views of what 'extreme' means.

I readily admit that I am particularly brutal on my equipment... but I also take good care of it - fluids/filters/grease are all kept up, probably more often than necessary. If anything does break, I fix it with new parts, under warranty if possible, and by the 'pros' at the dealership regardless.

The TC55 has held up well since I bought it new, with the following 'issues':

I've blown and replaced two sets of front ring&pinion gears in the first year, and then put an entire new front differential on it, all done under warranty. This wear was due to extreme FEL use without maintaining appropriate rear counterweights. Once I added more rear ballast (400lbs wheel weights) on top of CaCl-filled rears from day one, I don't seem to have any more issues with the front end (but discovered the next weak link - see below).

I fried the PTO clutch after installing 500+ fence posts with a PHD over a period of 3-4 days. We were moving pretty good, and I was very hard on the PTO to get that done. The clutch was replaced under warranty and I baby the thing a lot more since then. Sometimes you just have to go slow, or get bigger equipment. No matter... I have a new PTO clutch today.

I've replaced one FEL bucket curl cylinder that blew. It could have been rebuilt, but was replaced under warranty.

I've had the steering connecting rod straightened 3 or 4 times after driving over boulders during some spirited sessions in the mud. This is not really a major issue.

I've had to replace both lift links for my bucket due to bending from carrying too heavy a load. This was after I installed the rear wheel weights, so this is the obvious weak link in the design, and an intelligent one, since the lift links are only around $100 for the set of four pieces.

Tires have been punctured several times; tubes were installed and they've been replaced a few times. I have one tire (a rear) that has never seen a puncture).

I replaced a complete rear fender (not under warranty) after wrapping a chain drag around a rear wheel... that was a scary experience.

The heavy-duty Bradco Grapple bucket has a very slight bend in the bucket from too heavy a load, but it doesn't affect it's use in any way.

I've caught a backhoe line or two in between rocks, and simply replaced them. The hoe has been used well and shows no signs of wear or reduced capacity.

The backhoe frame connecting pins and frame connections take a lot of abuse, mainly because they reduce your ground clearance and I used to have a lot of boulders around here. I've had them bend so much I had to pound the pins in and out attach or remove the hoe. I replaced the connectors and one of the pins with new parts and all is well.

After a little more than two years and nearly 500 hours, the TC 55 still looks great and runs like a top. Everything that failed has been replaced with new parts (except the steering rod which was just straightened with a shop press and put back to use). If I were to wash/wax it and replace the worn tires, you would have a tough time telling it from new.

I bought it to use it; which I have done. I estimate it has paid for itself at least twice over, and possible three times in the past 2 years, if I were to have rented equipment or contracted someone to do the work I have done.

john_bud · Apr 5, 2006

Jim,

Typically every 5-600 hours and/or at the time of yearly maintenance you should closely inspect all of the structural members of the loader, hoe and mounting points for cracks, loose bolts and flaking paint (a pre-crack sign). Cracks should be welded up as soon as they are found. Drill a stop at the ends, v-groove and weld them up. You should also test the joints for slop in the bushings. Too much slop will oval out the bushing mounts, then you have to line bore and use oversize bushings. (couple hundred bucks each hole) You really can't "hurt" the hydraulics thru use as long as the filters are good and the fluid dry (no water). Overloading will release the relief valve. Worse thing that happens is the fluid gets hot and the spring gets a bit weaker resulting in it opening sooner. It's good practice to test and set the reliefs at the same time you check/set the valve clearance for the engine. Every 2-3 years or 1500-2000 hours depending.

Just using the loader and hoe will lead to cracks. Minimize the shock loading and you will maximize the time it takes for the cracks to appear.

jb