I have began to notice, upon acceleration, significant movement in the transfer case shift lever. Back many years ago when I was young and agile enough to crawl around underneath vehicles, that movement in any transmission lever, accelarator peddle, etc... could be a significant diagnostic for a loose or worn out motor mount. Is this a common problem for this year and make? I have a little over 113K miles on the truck and it is a 5.4. Is there a way to confirm whether or not it's a mount issue short of taking to a dealer?
Or maybe it could be a tranny mount?

 

Must be a dumb question, sorry. Heading to the dealer to probably break the bank again.

 

Haven't been aware of motor or tranny mount issues with this generation of trucks. I wouldn't think it would be too much to find. Good luck.

 

Not a widespread problem, many have electric shifts and never will notice it.

Motor and transmission and transfer case are all bolted together, they "rotate" in reaction to the throttle together. Since they are bolted together, it's reaction to torque applied at the transfer case output shaft that you see. In lower gears where torque multiplication is greatest the reaction is often greater.

Could be a worn or torn motor mount, or a loose one, or normal for the miles? One way to check is crawl underneath and check bolts. Then open hood, have friend stand beside truck and watch engine, shift trans in low and hold brake and apply throttle and watch motor.

I tore a mount once, you could hear a thump when you let off. To get through the weekend, I chained the left exhaust manifold down and took it easy. Some vehicles now have motor mounts that use molded rubber but the bolts pass through hoops, etc ... so even if worn they can't rare up like that one did and so they don't tear like that one.