"Everythings Leaking" According to Mr.Lube

So everytime I go into Mr.Lube for an oil change they tell me how everything that can leak, is.
 
But the funny thing is, I've never seen a puddle or even a drip under my truck. I have alot of skid plating underneath so I cant really see everything and im definatly no mechanic (yet)
 
but what exactly am I looking at replacing? One guy mentioned that my axle something or other was leaking and if I drove in 4hi that it would grind and mess up.....low and behold I used 4hi many many times without a hitch, other than the fact that 75% of the time I hit 4hi I could hear and feel it engage, whether thats bad or not i dont know.
 
but anyway, I can see at the bottom of my motor that its all black and crusted up, yet I very very rarely have to add oil between the 5000km intervals.
 
any insight appreciated and I can get pics of anything if you want to see them.

Probably just looking to make more money. I would take it to someone you trust to take a look at it.

thats what 1 would think, but they dont even do those repairs there......fluids only.

I would honestly put your blazer up on jack stands and take a look for myself if they said its leaking! Inspect the undercarriage for wet spots then touch them to see what it is!! Take the skid plate off to reveal what you can't see!!

Alot of the times there will be a small leak near the top of the engine, and over the course of time, the grease boils down and coats the engine block so no one really knows what exactly is leaking..it just looks like a terrible mass of lube and grease and black nasty.

Use some engine degreaser, clean it off real good, and then see what comes back.  And of course check all your fluids and what not in case something actually is leaking.

ya, lol if only i had some place to work on her.....

You don't have a buddy's house or family member that would let you use there driveway for a little while???