Even though I live in a State where Inspections are not required there is no way that I would use Spherical Rod Ends (SRE) in steering linkage for a street driven vehicle. Race cars are different, have no problem using them there but really only for weight reduction.
Tie Rod Ends (TRE) were designed for street use and they're more than capable off-road. They do have an angularity limit that is exceeded by an SRE's angularity limit. Do you really need that much angularity in a tie-rod or a drag-link? A TRE is wear compensating and the act of greasing one flushes out contaminants. An SRE with a grease zerk has no business being in any steering system, those are the weakest possible option.
If you insist on using SRE's in steering then at least put some Seals-It washers on them.
Sorry, but this is a sore spot.
The whole phrase "DOT Approved" is purely marketing. The DOT doesn't approve anything. They have no way to test anything for conformance to their stds. Each Mfg of DOT compliant part(s) certifies thru testing and written QA/QA policies & procedures that their parts comply with DOT standards. If/when they don't and have been determined to be contributory to a problem, then they get a visit from some unhappy Feds. If a mfg is going to mark "DOT" on the part then they'd better be able to show that the production has been holding to the DOT stds for that part.
The chinesium clones of a reputable mfg's parts is a particularly foul offense.
The German TUV DOES test parts for compliance. The TUV's set of standards is nearly identical to the DOT stds, so if a part is marked "TUV", then it can be assumed to meet DOT stds., but it's still not "DOT approved".
