I just received my first batch of parts for timing belt/oil pan gasket rebuild and both tensioners have plastic gears. Should I be worried? All the belt pulleys are INA brand which I've heard good things about. Also, the timing belt idler is plastic while the balance shaft idler is metal. All the plastic ones are made in Slovenia while the metal one is made in Germany.

Just wondering if there is any experience with the plastic parts or if it's a relatively recent switch to the plastic versions. Seems like metal is a much better choice for these parts...

 

If you have a 1986 turbo then the timing belt tensioner and the balance belt tensioner are plastic body on metal bearing/center section. No worries.

The "late style" water pump which you should have by now uses a 46?mm diameter plastic body on a bearing.

Balance shaft idler is metal, yes.

 

Nothing wrong with plastic ones, usually when bearing becomes bad, plastic still looks brand new.

 

When was the last time you did belts?
They have been plastic for at least 11 years (since I bought my car )