Yes, a loug BANG! followed by smoke and then the idiot lights come on...then you know you have 1.4 seconds to replace them.

 

21k, you will be safe for a while, mine lasted 76k (luckily) i did my cams,now i wish i did gear drive cams, that is what i would do now! go gear drive cams

 

No it takes out your motor real good....

 

30 k around when you have to start thinking about it

 

The tensioners in this photo have 27 k on them. You need to start looking sooner.
I have personally seen them last far longer, I saw some with 48 k look like he just replaced them,..... but some go much sooner.

27,000 miles did this:

 

The previous owner did the gear drive on mine, and I'm certainly thankful for it. I know if he had not, after reading the posts here, I'd be sweating bullets.

 

I changed out my cam chain tensioners at 35k miles and put in the S&S 510G gear drive cams. Also, put the S&S 510G's in my GF's Dyna. Best mod to both bikes that we have done. The torque difference between the California stock cams and the S&S is very noticeable. And, I don't have to worry about those damn tensioners anymore!

 

Was it done at a dealer shop? And, how much?

 

Feuling also has a kit for upgrading the cam drive but it costs a bit more than the H-D kit if I remember right.

 

+1 on just check 'em.
Only about an hour to do yourself. Cheap insurance.