C15 Vibration

The gear with the weights is the cam gear, the bull gear is behind the front cover (technically Cat calls it the cluster gear). I don't think that's your issue, I've never seen a gear train issue cause a vibration like you describe.

If #5 is failing a cutout test, I'd focus my attention on cylinder 5. Are you getting any noises from the air cleaner, like a valve isn't seating fully? Flash code 94 is a IVA on #5 or 6 (I assume #5 at this point). Was that checked? Solenoid, housing, wiring?

I have seen many harness failures that don't set injector faults in the early stages. I test the harnesses by totally disconnecting them, supply each wire with battery voltage, then load the other end for a voltage drop test. It only takes a couple strands of wire connected to look good with an ohm meter, you need to load the wires.

 

If an intake valve is not seating, you often get a noise through the intake from the compression blowing back. You get a similar noise when an exhaust valve is not opening. It's a pop - pop - pop or thump - thump - thump type noise. The noise you're hearing in the exhaust could be a number of things. Might just be a minor exhaust leak, or it could be an exhaust valve not seating. With a luod valvetrain, I'd check the overhead adjustment first and look for any issues up there. The Acerts were known for breaking rocker studs, there is an updated stud, the originals should have been replaced by now, but not everyone did it. The original IVA housings were prone to cracking.

 

I don't think that's a good idea. Apart from setting fault codes, you'd have to plug the oil port and find a shorter bolt for the rocker shaft. If the fault code is for the IVA not responding, I'd look very close for cracks in the housing before I changed the solenoid.

After you inspect everything up top, I'd test the injector harnesses. I disconnect them totally, all injectors, IVA's and brake solenoids. Make sure nothing is connected under the valve cover. Then I unplug the main harness connectors at the valve cover base. I use a jumper wires to battery + with a female pin crimped on the other end to power up each pin individually. With a Pin powered up, I use a voltmeter with my LoadPro test leads to check voltage drop. Then move on to the next pin. If you find any that drop more than a few tenths of a volt, the harness is failing. If you don't have test leads that load a circuit, you can rig up a light bulb to load it.

 

you can back the ivas all the way off to eliminate them. once the truck warm up it will throw an iva code tho

 

As far as your c.e.l. for IVA 5 & 6, 94 tells you the circuit is open, shorted or one of them isn't responding. You can test further with cat e.t. or test the harness and if that shows nothing pull off that IVA housing and swap it with 3 & 4. When you have the 5 & 6 housing off look for broken studs and cracks in the housing. Its a common problem if the studs haven't been updated. See if the code follows the housing or stays with the harness.

In the very first post, you said that when you had the clutch replaced the mechanic noticed the dowel pin that positions the flywheel on to the crankshaft was smashed. So who ever the last person was that had the flywheel off (before your clutch job) re-installed your flywheel incorrectly. The dowel pin did not get 100% smashed down to the surface level of the material around it, it just couldn't. So for some unknown amount of time your engine was running with a flywheel slightly raised off the crankshaft in one spot, no wonder it broke clutch springs. I'm sure you had the flywheel machined, but did you check flywheel run out? Next oil change drop your pan and check out your main bearings, see how bad it beat them up with the flywheel and clutch throwing its weight around off center.

I really think the flywheel being installed incorrectly is where you need to be looking as far as the shake.