Design Flaws: What would you do better?

[DrJim]

:BangheadMy JD 5425 (green) tractor has some great features. Ah, but the flaws. The fuel tank is a generous 30-something gallons ( Good!) but the tank is plastic. When they manufacture the tanks, I'm guessing they drill, ream, or otherwise do the final shaping on the various holes (fittings) in the tank. The black shavings plug the dinky in-line pre-filter that runs under the tractor--it's about the size of your typical lawn tractor filter. To change that filter, JD says to remove the fuel line and drain the tank first. Yeah, right. How 'bout some needle-nose vise grips with some rubber tubing over the jaws as a pinch valve. The darn filter is so small that most anything will plug it.

When we first got the tractor, it ran great. . . until it didn't. Had it hauled to the dealer, and it took them half a day to realize that their was a pre-filter under the tractor--it wasn't shown in their service manuals nor in the owner's manual. When they figured it out, yes, it was fully plugged with black plastic shavings.

My tank has a drain plug--yes, a plug, not a petcock. The owner's manual says "loosen to drain the water", but by the time you figure out it's not a hollow bolt with a drain feature, the plug bolt is out and the hole is spewing diesel fuel all over you.

The real PITA: The fuel filter on this particular tractor has a drain (yeah, I know, most diesels do). The manual says "loosen and let drain until the all the water is out of the (clear) bowl". But the thing goes "glug, glug. glug". If you drain the fuel filter water/sediment bowl, you'll have to purge the air.

First, loosen the screw on the filter. It's plastic with an o-ring, and it quickly comes apart. Only costs $ 0.99, but you don't happen to have an extra, do you, and you're 6o miles from the dealer. Pump the plunger on the filter until no more bubbles come out, then tighten the now shredded plastic bleed screw. Think you're done? Just getting started.

Now you have to go to the other side of the tractor and loosen a flare nut on a fuel line, and then loosen a hex plug on the side of the fuel pump (this one is steel, and it _is_ hollow, like a banjo bolt. Yes, that's the factory prescribed procedure. Pump the plunger on the top of the fuel filter housing until no more bubbles come out of the bolt on the fuel pump. Hold the plunger down while you first tighten the bolt on the fuel pump, then tighten the nut on the fuel line flare fitting. Wait--how are you gonna do that? The fuel pump is on the other side of the tractor from the filter housing. How are you gonna hold the plunger down while you close the open fittings?

So, this either takes two people or you have to live with some air in the system. This sure doesn't encourage frequent draining of the fuel tank or fuel filter.

 

[DrJim]

As for ATCO's remarks about Bobcat being a pain to work on, I don't think it's that big of a deal. I haven't had any service issues to speak of so far, but for me, that's all easy--I'll just take the machine to ATCO . Better still, take it 3 miles up on the side of Windrock Mountain and call him up. . . .

 

[DrJim]

At least on my Bobcat 773 (56hp Kubota), all the filters are a breeze to access, and the fuel air purge procedure is simply and foolproof. I can drain the fuel filter without getting air in the system--something my JD tractor won't do. Now for the case drain filters. . . where are those little buggers anyway? While I lose $80 worth of hydraulic oil when I change 'em? How 'bout it, ATCO? Where's your tutorial on that?

 

[Randy88]

On bobcats the routine sevice is easy, they made it that way, the work starts when you go beyond the routine service and have to actually fix something, or worse yet pay the bill for some other sucker to fix it, the stuff is beyond miserable to get to let alone replace, the engineers must have had head up the *ss syndrone when they designed it or never gave it a though that it would ever need to be fixed or parts replaced, everything on the machines take three times longer than any other machine out there and more cussing than most vocabulary has words for and thats on a good day. They made service points easy to get to and do and operator comfort and visabilty for sales and operating purposes but it ends there. The best one on my bobcat 743B I had was there was a universal joint on the backside of the engine that drove the pumps if I recall correctly, in the manual to grease it they stated "remove the engine, grease joint and replace engine" yea right like thats going to happen, nobody could design something that didn't require the engine to be removed to grease? How about an access hole in the side somewhere to put a grease gun tip through and shoot some in ever now and again? How about the stupid center mounted gear case that when you needed to get the bearings out you dismanteled the enitre machine to do it since its all backwards and you have to tear everthing out of the inside of the machine to replace spockets and chains, or better yet no drain hole to drain the oil out of the center case, your supposed to suck it out, and thats long before I ever saw Atco's suck bucket!

The best yet is to try and get those drive motors out when they sandwiched in the center case design and limited room to do it but the best is who was asleep at the switch when they passed out brains when they put the input lines to those motors towards the bottom of the housing where nobody can get to, why not closer to the top that would be more handy? I could go on for days about those machines and engineering and how bassackwards they did the simple things and even botched those up, but theres a hose in the back that drains the engine oil thats simple to do and the filter is like totally accessable as well, but they did forget to mention the grease jerk on the backside of the engine that needs to be geased about every couple thousand hours, that the saleman forgot to mention, and you really do want to do it because they couldn't afford the grease jerk on the splined shaft that holds it all together, that you need to lube up, if you don't it ruins the splines and you have to replace that as well when you finally get it jerked apart after it starts to vibrate and shimmy really bad from not being greased, but they saved that access hole and additional grease jerk on the splined shaft??? But the replacement part has the grease jerk in it, you just can't get to it to grease it, now thats engineering at its best, I even called the company to ask why they put a jerk on it at all and they told me that way you only have to pull the engine out part way to expose the jerk???? Part way is aparetnly a whole lot easier than the whole way and when I asked then when its part way out how do you get to it, the answer was simple since you have it part way out just finish removing the engine to gain access?

 

[Muffler Bearing]

oh Bobcat, how about when that top mounted fan bearing shells and eats into the shroud it lives in. Isn't there some weird 90 degree corner on the shaft that drives that fan? I remember some odd drive system.

 

[koldsteele]

Not really a design flaw but hows about the lil fella that climbs in chain cases with his brand new Nicolson file and sharpens everything up for ya....gotta love them cuts ...NOT ..

 

[DrJim]

Randy88, we lost a drive motor hose to the right side wheel motor on our 773 G. That wasted a day and a half, between fetching parts and finding time to fix it. And I don't remember (don't want to remember) but the hose probably cost $ 65 and the gallons of lost fluid another $ 75-90, all because of stupid or intentionally poor design. The hose was about 2" too short and rubbed against the top square edge of the center case. When I went to find the hoses, the Bobcat parts manager said, "Oh, yeah, that's a known problem. They have a hose guard kit to prevent that." Big help after the fact. The hose guards were cheap enough, just pieces of plastic that you zip-tie to the hose. We could have done the same with split pieces of any hose (heater hose, etc.) but you probably wouldn't have gotten them between the corner of the case and the hose. We skipped the OEM hose and had a hose made, just a little longer.

For years all I ever rode was a 742B. The 773 G is light years ahead of the '42. Easy maintenance, belt drive instead of that shaft you can't grease that eventually breaks, and wider/longer track for more stability and less fore & aft pitching. The turbo w/ 56hp makes a difference, too.

I have a leak somewhere, and I expect it's another hose about to give up.

 

[derekbroerse]

A few favorites off the top of my head...

My 1959 International B275 diesel.... who in their right mind designs a tractor that has the steering running THRU a tunnel welded in the middle of a fuel tank? Seriously, did someone really think this was a good idea at one time? Not to mention, this is a tractor known to have major steering problems on top of it all, mine also leaks diesel from one of those fancy welded seams somewhere down inside the tank.

1973-91 (and likely others) GMC/Chev one ton cab-and-chassis rear brake lines and bleeders... the backing plate is less than an inch from the leaf springs and cast spacers, meaning nothing but an ill-fitting wrench can get in there to open the bleeders, probably not a big deal if you like in the desert or something, but up here in the snow belt we get the many joys of road salt, in this case, bleeders and line fittings that rot away and no wrench, even fudging with metric sizes, can grip them tight enough to turn them. I six-point socket would work nicely, but oooops sorry not enough room for one of those, let alone a ratchet to turn it with! A little more space, even 1/4" would probably be enough. Nope. Alternatively, that big clunky cast iron spacer beside it (on one of my trucks at least) could have had an access hole cast in it so a socket and extension could be used. Nope. Instead, you get the joy of either a full brake teardown from the front (full floater axle and all) or dropping the axle housing, also fun on the snow-belt vehicles.

My '96 Cadillac.... does everything have to go thru the computer? Including the radio?? I want to swap in a modern deck instead of the old tape player, but removing it sets off trouble codes in the guage cluster! The solution? An expensive wiring harness that moves the factory radio to the TRUNK and stays connected to the system, and installing the new deck as a stand-alone system. Idiots. All so I can have a message on the speedo that tells me when my tape player needs cleaning, and my seatbelt chime can come thru the speakers instead of the usual dinger thing. Oi.

And my favorite beef, its not just engineers, ARCHITECTS drive me insane. Each should be forced to work a full year as a landscaper, for grass cutting and snow removal, before being allowed to design a building at all. Things that look nice should not take priority over whether they are servicable or not. Moves like placing handicap ramps jutting 30 feet out into open parking lots, randomly placed handicap spots in any place that would make sense to pile snow, or fancy scalloping on the side of the building that collects tons of snow and holds it overhead of people walking on a sidewalk below, just waiting to drop on them, or at minimum re-bury the sidewalk in snow again. Or cheaping out and not making the sidewalk 18" wider so instead to protect the building they install those stupid parking-space curb things... a ton of extra hand-shovelling work in the snow and a tripping hazard for the people walking there. Fire hydrants installed not where they would be easily accessible to use, but where you would commonly have small snow piles from bevelling entrances.

Or designing a parking lot drain system to steeply slope all into the middle of the lot rather than around the outer edges--this creates many low spots where a snowplow can't reach all into the bottom to remove it all, large dips and holes to drive thru for customers, and my personal favorite, run-off from the snow piles you've carefully pushed to the edge of the parking lot.... so when its a nice sunny day and you get a little melt time and the temps drop below freezing again at night, you are greeted in the morning with that beautiful black ice skating rink! All this could be avoided with the drains being around the perimeter and sloping away from the building. Much easier grading too.

I was on a team of electrical contractors once for a government job, they were renovating an office building. Building was square, of course. But the architect thought it would be really nice to have S-shaped sweeping hallways inside.... ie: rounded interior walls. Made for some strange shaped offices. Now, why did no one notice until afterwards, that their furniture is all 90* cornered? Square furniture on round walls is idiocy. Looked stupid and wasted a ton of space.

There, that's my rant for today.

 

[Tulp]

I've got a few, The oil filters on our 535 cat skidders are so close to the fame that once they get about 2000hrs on the motor mounts the filter hits the frame before the filter is free of the filter housing.
or 416 tractor/backhoe you have to pull the engine to change the exhaust manifold gaskets.
There are lots more just few that are buggin me right now

 

[3rdGenDslWrench]

How come on the newer Cat excavators they dont put enough room in the flywheel excavators so that when the coupler starts going bad the material falls out? Instead it starts to pack in there, eventually pushing its way into the oil pan....plugging up the oil pump pick up tube. Then BAMM one minutes she's knockin or just LOCKED up?

 

[lantraxco]

According to CAT the coupler never fails, ergo no need to allow for debris damaging other components. Just ask 'em, LOL!

Cheers,
Lanway
www.lantraxco.com

 

[3rdGenDslWrench]

Yea...thats what the manual even says lol. Yet I've replaced one coupler on a 330C. Then on a 345C and a 330B I had to rebuild the engines when the couplers began to fail.

 

[RobVG]

'05 Ram 2500

Chrysler's "Cab Forward" design. Should have been called engine backward.

 

[rare ss]

330C travel motor's, not sure if its been metioned, but the piston which acts on the swash plate to alter between HI/LO speed is hardened but the bore in which is runs isnt so it wears out and theres only a steal piston ring to seal so when the bore wears to get bypass and them you get one track on high speed, one on no so high speed and the machine wont track straight!!
took us acouple of days to work it out it was a travel motor fault only after we stripped the travel motor to see what was wrong inside
we machined the bore out and fitted a hardened insert into the housing and matched it to a new piston, we had 4 other 330C's with the same issue and the local CAT dealer had 20 travel motor housings in the machine shop getting the same thing done

 

[STRPETE]

I don't even know where to begin with trucks. Anything built by Volvo/ Mack is a mechanic's nightmare. If you're going to build short hooded trucks with the engines under the dash, then make an access panel on the damn firewall that's easily removed. (Ever try to change the fuel line to the back of a 3406E or a DD60 or N14 in a Freightliner Century?) The Pete387 and KW T2000 aren't any better. Whoever thought a tranny cooler mounted to the top of said tranny with heater hoses going to it with no shut off valves should not be allowed to reproduce.
They should stop trying to make trucks idiot proof, and make things more mechanical, and less computerized. Make high maintenance items such as filters, alternators, D2 governors accessible. The ADIS air drier was a massive brain fart for Bendix. You can't bypass them or do anything but replace them where the truck sits when (not if) it fails.
Another dandy is a Kenworth with the exhaust above the trans with a Super 10. (The super 10 is a marvel all of its own) The flex pipe breaks, melts nylon air lines, and there you sit.

I could go on for hours. I strongly agree that the engineers should have to work in the field to gain some perspective from the poor b*****d who has to fix this crap in the middle of the night in a snowstorm.

 

[RobVG]

(Ever try to change the fuel line to the back of a 3406E or a DD60 or N14 in a Freightliner Century?)

I think I know the one- it's the return line out of the back of the head? You have to do it blind with a couple of fingers. Did that on one of our C15 Kenworths.

 

[wnydirtguy]

I think all engineers should be requare to have a least 5 yr of mechaican on equipment before they get there degrees

I agree. just like doctors have to do an internship. Learn how it works and how to fix it before you can design it.

 

[Impact]

If I could redesign her, the brakes on her car would last longer than 15,000 miles.

If I could redesign me, I'd have an eye on the end of my finger. I could see the dust on top of the fridge, the wax in my ear, and find that screw slot on those hidden hose clamps

 

[typ4]

We have mostly Deere equipment, older but reliable, who was the dumass that put batteries in front of STEEL oil coolers to rot them out.. Also never worked on a skidsteer before, have an 853 w isuzu diesel, put on an exhaust pipe, I am 6'3" and big, read 380, had to death wheel off the nuts to get it off, did they not know about never sieze at the factory, or nuts that nuts rust round.

 

[D11RCD]

Cars...

Oil filters and batteries on new cars. Need i say anything more?
1997 Toyota Camry Vienta: The entire engine has to be lifted out to get to the back row of the block to change spark plugs. So many cars are made like this. :Bangheadointhead. Dad and I have so many more...:beatsme

OOH on the subject of digital in cars:
https://www.heavyequipmentforums.com/showthread.php?23434-7x5-Car-Trailer-light-Problems
One bulb backwards made the computer say traction control fault, cruise control didn't work with the lights on AND the parking lights on the front lit up when we braked.:Banghead

I feel for you all though on the big machines, they have just as many problems.