On an average how long should shocks last. Currently have 51k with original Goodyear tires.

 

Stockers are about shot as soon as you pull it off the lot.

 

Not true. I have 41,000 miles and they're still fine.

 

Ridiculous thing to say.

 

IMO, with 51K on the OEM, I'd be looking at a good set of shocks. Now, I'm one of "those" guys that will take a brand new truck home, and change out to a better aftermarket set right from the gitgo, and get a pretty big improvement in ride, handling, etc. I've even been known to have an aftermarket set sitting there in the barn before I even get the truck.
Yes, good shocks are more $$$ than OEM, but if you're anything like some of us, well worth the $$$.
As said, I'd be looking at new shocks.

 

Same here. I have just over 53k and the ride in the back still feels ok. I do plan on swapping my 5100s this weekend to get rid of the extra bounce/hop that is somewhat there.

 

I just changed my rears a few weeks ago, had 65,000. They were not leaking and probably would have lasted a while longer. Only reason I changed them is that I got a really good deal on a set of Icon shocks. Now that I have changed them I understand why guys like johnday in BFE change out from new to aftermarket immediately, the ride improvement with good aftermarket is very noticeable.

 

Changed mine at 70K.

 

so the rears should easily collapse with light finger pressure at 16k miles? Mine did...

 

My right front blew out at about 65K, started leaking profusely. I upgraded to Bilstein 5100's all around and all is good.