Grohe volume control... plastic linkage tube

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?

Simply, the valve requires more effort than the material can bear. Retooling can be expensive and Grohe may have decided it is in their interest to just send replacement parts when needed. Ask for several pieces so you can change them out. Also you might suggest to Grohe, that the cartridge my be turning too stiff. A new easier turning cartridge could be the fix.

Europlumber is right,to much stress on the parts.Moen has the same problems on their widespread faucets.The stem could be to stiff or to much pressure when turning off the stem.These are almost a one finger type of system when turning off.

yah, lessen the stress on the parts. Europlumber share a good advice. I haven't tried that but the way it looks that the way how your problem will be solve.