"Defective" is misleading. The wheels aren't really defective, but the engineering was (or more likely, the corporate decision-making was defective). These wheels simply aren't strong enough for the backhoe application, especially in a real construction environment. I'm a utility (telecom) contractor and we use this machine on the job. The reason the lug nuts like to go loose is because the wheels have too much flex when subjected to the typical side-to-side lateral forces they experience when coming onto and off the outriggers, re-positioning the machine with the backhoe (like all backhoe operators do constantly) and occasionally having to use the hoe without the outriggers down, etc. These wheels are probably OK enough for a Homeowner Bob situation, but they won't stand up to the real uses this machine was supposedly designed for.
Mine started loosening up often pretty early on (less than 50 hrs) and the spider cracks were noticed not long after. Others I know have had the same issues. As the cracks kept appearing and spreading on both wheels (by 500 hrs) and I figured out why it was happening, I approached dealer with the problem (had the 5-year bumper-to-bumper) and they wouldn't fix it under warranty because it wasn't from an 'accident', and there was/is no factory recall.
So, with fine cracks spreading out several inches from every lug on both wheels, and not wanting to try and weld all of that and couldn't have expected that to be successful anyway, I got out the plasma cutter and drill, and fabricated some plates out of 1/4" steel (see pic attached). It took a bit of regular re-torqueing over a few real-world machine hours to finally get them properly cupped into the wheel curvature, and I haven't really had any problems since. Lugs stay tight and it pretty much halted the cracking for quite a long time.
Over 1600hrs on the unit now and I'm just beginning to see that a couple of the already-existing cracks that I sandwiched in with the plates have finally made it out past it on one wheel and I'll be re-placing both rims before long. Plates let me get over 1,000 more hrs out of rims that were already heavily damaged & otherwise beyond repair. I will absolutely be re-installing them on the new rims and hopefully prevent the issue from happening again.
As noted above; These factory rear wheels just aren't up to the task they've been given. I'm sure they are used on other models/applications without much issue, which I assume is why there hasn't been a recall because the overall failure rate is probably fairly low all told) but they just can't handle the typical abuses of a backhoe.
So, for you other l47/L45 owners and fleet guys, here is the DIY 'fix' that has worked out fairly well for me so far. Hope it helps.
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