[REPTAR15]

Noticed a weird rattling sound coming from under the truck. Was trying to re-create the sound again and found that after making a turn or making complete stop and accelerating to about 10 mph a loud rattling sound happens for about 2 seconds. Doesn’t sound like bad CV joints because they would be grinding.

Could it possibly be a loose bolt holding the exhaust? Maybe Heat shield?

 

[Rapdav18]

Pop your hood. Look behind the brake reservoir if you have a grey one way check valve switch it to a blue. They are available atctge dealership for 15-20 bucks. Sounds like premature independent wheel hubs trying to engage. It’s that or your iwe air lines are leaking. Your losing vacuum. It’s always been an issue on 17 and 18 models. I’ve repaired mine and 5 others already.

 

[Rapdav18]

To recreate the noise you must accelerate on a slight hill or incline. The noise will start as the truck thinks your telling it to go into 4 wheel drive even though your not. It’s the lack of vacuum pressure allowing the hubs to move is being engaged. That’s the rattle. Your correct in hearing cv joints as that’s where the engagement rings are. That small amount of vacuum actually keeps them pulled in until you push 4wd telling the system to cut off the vacuum thus allowing full engagement