I have four different toothbrush sized brushes that I use as well to clean various parts of my Jeep, ranging from soft nylon to stiff brass. I'm extremely OCD about cleaning it after I take it out, and anytime that I work on fixing something I have taken the time to clean and inspect the surrounding areas, and applying proper coats of Rustoleum paint where I can.
The owner previous to the person that I bought the Jeep from took care of the underside mainly with grease, but I have eliminated 98% of the clay mud that clung to it - which probably lightened my Jeep by a couple of hundred pounds overall (I shit you not).
I knew that it was dirty in several spots underneath when I bought it, I spent an exhausting bit of time on my back scraping test areas and checking for rust and damage before I handed over cash, but somehow after having cleaned everything - the only major rust on the entire vehicle was under the hood — mainly on the exhaust manifold that I am replacing at that.
As mush as I dislike an inch of clay under my Jeep, whatever that guy did with the clay-on-grease kept it from rusting. He was also motivated enough to preserve the frame with internal frame paint and a strategic drain holes in a couple of spots on each side.
This Jeep does tell some stories of oddities though. For example, there was a cheap Moog HD steering kit with malfunctioning TREs on the front, where the steering knuckles were drilled out (unbeknownst to me when I bought it) to support the larger TREs. The front DS is a 1310 yoke that mates up with the front pinion yoke, which takes a 793 u-joint.
I still do not know if th DS was replaced to support the 5.5" RE long arm lift or if the previous steering kit got destroyed in an accident or wheeling incident. I found out not long after one of my CV u-joints in my rear shaft had left me broken down that the SAME mating setup is on the rear axle pinion to rear DS yoke (1310 <> 793). Scratching my head at the fact that the owner was pretty well off to financially, spent the money to regear to 5.13, but had the unsafe, garbage steering setup with the Frankenstein yokes.
That said, I'm somewhat ok with the franken u-joints, as I may have mentioned around the time that I discovered it - a trusted old timer that I know who used to build NASCAR rear ends, said that in the late 70's and early 80's, they had to make similar u-joints, since there weren't but a few rear diff options back then, and they stayed balanced and held up to racing.
I guess my point is that it's hard for me to tell where this original owners head was at. He threw money at it to ensure that the lift was well executed and chose to go with higher end shocks that do work very well for this setup (Rock Krawler). He just never bothered to clean some of the mud that was caked onto the headers and some other areas of underneath.
On a side note, these double cardan u-joints kind of scare me, but I have learned that visual inspection is just as important as checking for play. The evening that my rear u-joint went out, I did a thorough preflight check and there weren't ANY signs of the u-joint going bad. It was t until I got the DS on my bench that I saw that the trunion neck where the bearing cap sits over had ovaled out. I also recognized that the bad u-joint wasn't a Spicer, but I have since replaced all of the DS u-joints with Spicers since then.
