Tubular upper arms-I feel lucky tonight

70Hardtop said
72bluNblu - here are a few photos of my tube UCA's. These were bought over 6 years ago, i bought them a few years ago from the guy, but although he told me the brand, i can't remember. CAP does NOT sound familiar though, but these do look like ones in the original post. I would like to think that if these were manufactured over 6 years ago, then the incompetent welder (responsible for the failed ones) might not have done these ! Its not the CAP products in general that are at fault, its the poor welds turned out on some of them by some idiot who shouldn't be working there. These ones here have the Hiem joints, and i have also posted some closeups of the welds. Can you or anyone ID the brand or see if the welds look MIG or TIG? Someone on this forum said that gussetting (a la Magnum Force, Hotchkiss and Firm Feel) is not necessary. I disagree. You only have to look at the small amount of material on these welds and know of the huge loads that they have to carry, to see that some sort of gussetting would be adviseable. Its liek a road bridge - most well designed bridges could easily perform well 98% of the time with 25% of their support material removed -but its that freak strong storm combined with a load of heavy trucks that will bring it down, so the engineer's have to allow for this. So too the UCA - they should be able to withstand radial and side loads that would not be experienced in normal driving.

Those are CAP arms and they are MIG welded, but I would have to agree with you in that those welds look good. Not sure what 1qwkScamp is talking about, they have good penetration and look to be right on for a MIG weld. The edge of the weld bites into the metal, there's no shoulder or build up of filler rod to suggest that the weld was too cold, and the weld has a good fillet to it. There's a little blob of filler metal on the bottom of the one weld, but the underlying weld looks good, that's just where the welder overlapped the start and finish of the weld. I wish the welds on my CAP arms looked as good. On that note, I've still not broken anything in about 10k miles now, and I drive a lot of backroads that have pavement quality issues. I will be replacing them though, just not worth it. CAP seems to have a quality control issue, MIG welding to begin with is less than others do, although as long as the welds are good it shouldn't be a problem. Their design seems fine as well, but they definitely let poorly welded arms out of the shop, which is just unacceptable. If you got a set with good welds they should perform fine.

The TIG welds on the RMS welds are good too, almost too hot right at the edge of the ball joint socket where it did undercut the edge a little. Not a problem, and far better than a cold weld, but just a little more filler rod in that area would be perfect.