Wonder if many of you out there have had problems with this setup. Last year built a house with two showers, both have Talia level handles and 29 273 rough-in valves. There are a couple of plastic parts that link the valve to the lever, the problem part being the inner one, which is a black plastic tube with ribs on the outside, and on the inside of one end. So far we have replaced one due to stripping and the other is developing some play. My plumber installed these but I did the replacement on the first one and it appears that he installed the parts correctly. I checked the other and it's the same, appears to be correct. It is beyond me why Grohe can't furnish metal parts for these valves. Anyone else had problems with these?