It's fascinating how long the memories of trips past can survive in your vehicle. I was getting Moab fine dust out of JKU's skid plates for over a year since, but that was fine dust. Here, this collection enough to grow plants in survived on the suspension element for FOUR MONTHS - and three intense washes, each more thorough than the previous. And three other trips over a different terrain with distinctly different soil signature. And I only saw it when I was rotating the tires, when the suspension was extended completely.

It's an interesting design choice - to make grooves that can hold stuff and spread happiness around seals and grommets. Oh well, I guess I'll have to keep learning how to get rid of this stuff as I go

Any tips and tricks as to in which nooks and crannies the dust and mud routinely collects that are not visible to a naked eye?

 

Great picture, and thanks for the warning! When I bought my gray market SIIA 88 back in 1996, it came with English mud packed into every crevice. 10 years later, when I put it on a new frame and switched it from RHD to LHD, I still found deposits of English mud and crud under my own Michigan mud when I took it apart.

 

Those grooves are a result of basic engineering theory. By distributing the material further away from the central neutral axis the force put on the beam is better resisted than if the material was further towards the centre, whilst also saving weight by removing unnecessary material on the neutral axis.

 

I use a gutter cleaning wand to get into and under places on the trucks when cleaning them. Here's the one I use:
It works fantastically for spraying up under the vehicles, getting salt and mud out of places that would otherwise be tough to get to.