UCA Bushing
 

On a similar note, can the UCA bushing be replaced?

Ya, people have said that you can, but I just replaced mine since there were so old. I also didn't want to deal with putting the bushings back in.

If the bushings are history, it's a fairly safe bet that the ball joint isn't exactly in mint condition. Given the cost of bushings versus the cost of the complete UCA, bushing renewal does not make a lot of sense.

Ya, that's exactly why I replaced the whole unit (because the seal around the ball joints was gone and I would just rather replace the whole thing while I am down there).

I would be worried about a Lowe's bolt, you need to match size and hardness to the original to be sure you will not have a bolt failure in the future. the reason it was so hard to cut is that it is a high grade bolt. If you cant get one from a PNP, I would go to the dealer and get one. here is a metric bolt properties sheet FYI

http://euler9.tripod.com/bolt-database/22.html

Be careful with the smaller bolt...it can wallow out the holes, and then even the proper bolt will not fit properly. Also, due to movement, the front suspension geometry will not be good, resulting in a poor or self adjusting alignment.

I had to special order my bolt from the dealership. I'll bet you could get it from Phil at Fastlane though, if you aren't close to a dealer or want to save a little (it wasn't exactly expensive). The part number for my 78 240D was 000960 012315. I would guess the bolt is universal across the w123 line.

I'm guessing it's not urgent but I'd go in and replace it with the factory spec bolt at some point. Pain in the butt but personally, I'd do it.

Glad you were able to get the bolt out ... it was quite an adventure when I went through it so I know what you had to deal with. I actually just used heavy duty metal-cutting blades on the sawzall and they did get it done, although I had to go through 2.5 of them (part of the problem was only a very small portion of the blade could be applied to the bolt due to the restrictive area, so that spot on the blade just got wiped).

X2.

The hardness, corrosion resistance and strength of bolts in automotive applications is usually fairly important. If a dealer is not available, at least go to NAPA. They should be able to provide something appropiate. A suspension component is one place not to save a few $.