Q: Where are these L joints? on 2002 Chevrolet Monte Carlo

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How much should L joint replacements cost with labor.Also the mechanic advised me that being I am getting this job done he should replace the belt tensioner being the car has 100k and he has to remove it for access to the L joints?
(1) Answer
I swear I have looked all day and cannot find what an "L" joint is. I was going to advise of U-Joint replacement till the belt tensioner access was thrown in there and I said "self" maybe you should just bite the bullet and ask what it is. HELP