Why in the world do they not make the U joint itself rebuildable like every other car I have ever worked on I can't belive it could cause a blance problem.

I once had a 68 Caddy that had a bad center U joint the Dealer told me that it could not be rebuilt, but a mechanic friend that worked at the local Olds dearlership said that was a bunch of crap and got me the parts saving me several hundred dollars.I got a sneaking idea that somehow that MB joint could be rebuilt by a DIY'er.........
William Rogers..........