So as I posted a few weeks ago about my truck making this slam noise whenever I start it up and shift into gear after I drive about 10-30feet I heard this slamming noise almost like my front axle was trying to engage but it didn't. I don't think that was it though because I tested my 4wd out and it shifted in and out with no problems. Anyway that only has happend about 5 times in the last month. But today when I was leaving work , I pulled out of my spot and I was going about 10mph and heard this grinding noise coming from up front , and then it stopped and it didn't do it again....yet. I replaced both front hubs about 6 months ago. But maybe the hubs went bad again ? Or I was also thinking maybe the brakes could be locking up ? Any help would be greatly appreciated (:

 

check the front axle u-joints. they turn all the time, even in 2wd. they should be tight, no wiggle, bearing caps and grease seals intact.

if nothing obvious, put the the front end up on jack stands and rotate everything.

 

I'd also check the vac line going to the cad for 2wd.

 

Was also thinking that. So our trucks obviously have vacuum going to it all the time, about 8 months ago I had a CEL on came out to be small evap leak, went off,went on, etc....2 months ago came back on and now it's a large leak. Thinking since I have that leak maybe the front axle is trying to engage ? Also could a bad plenum cause a vac leak?

 

I don't think evap leaks would coincide with the cad's vacuum. Check the lines for the cad like zman said. And yes a blown plenum is a vacuum leak.
I know someone who had a similar problem with grinding up front and it ended up being the engine (or transmission) mounts.

For the evap codes, what are they? Make sure the gas cap is on tight obviously... Check the evap lines around the charcoal can and the purge valve, etc.

 

I forgot the code I had. I don't think it would be the mounts because all of the symptoms happen under 15mph. And the line that comes off of the cad leads to where ?

 

P0442 and P0455 are evap leaks, usually on the hoses in/around the evap canister and the purge solenoid. they're actually very easy to fix with some medium (5/16ish) and larger (9/16-5/8ish) vac hose.

its maybe possible that a vac leak could allow the cad collar to flop around and grind, but i think its unlikely. if the cad collar is grinding, its probably a stuck vac cad shaft, not a weak vac.

evap fix
https://dodgeforum.com/forum/2nd-gen...-leak-fix.html

 

Your CEL ever come back?

 

nope. been off for about 2 months now.

 

I'll try to take a look at it tmrw If not I'll lift it up at work Monday and check the vac lines , I'll give an update, btw mine goes on and off , been off now for 1 month, but it will come back, starting to think my plenum is poping the code off ?