3.5L HO Rocker Arm Tick - What causes it and the fix
In the 3.5L engine over time there can develop a rocker arm tick. Its usually noticed when the car starts up. For some it may go away after a few minutes of driving. over time however, it will last longer and longer and sometimes may come back while driving here and there. The tick is caused by a rocker dowel pin SHEARING, yes shearing off.
(photo credit:Tbird100636 via LX Forums)
when this occurs the dowel that the rocker arms are located on tend to shift when in use. From the shifting the oiling holes become misaligned and the rockers starve from oil a bit.
(photo credit:Tbird100636 via LX Forums)
you can disassemble and reassemble your current setup, or you can simply buy a whole new setup. when i recently did mine, i just bought the new one as i already have 164K miles.
In most cases after shaft removal, you can see where the wear and movement occured
(photo credit: Chickenstrip via LX Forums)
if you chose to rebuild yourself, here are the part numbers (credit Tbird100636 via LX Forums)
If you go the new assembly route:
Warranty pays just about 2.0 hrs for both banks. They may charge 2.5-3.0 hrs cash.
-Exhaust rocker shaft 4663998- $28.10 list X2
-Rocker shaft pedestal kit (enough for one head) 5191332AB- $63.80 list X2
-Intake rocker shaft (generally not needed, issue is with exhaust shafts and pedestal dowels) 4315823- $36.60 list X2
-Left-3 per head, total of 6- 4573459- $26.95 list
-Right-3 per head, total of 6- 4573460- $26.35 list
-Exhaust rocker arms-3 per head, 6 total- 4663996- $50 list
The reason for left and right intake rocker arms is because the exhaust rockers operate two valves, but the intake ones operate only one valve each, so you need three right intakes and three left intakes. List prices, dealer is free to set prices.
The warranty time to do both heads is just over 7 hrs.
Part Number: 4892293-AC
example online: http://www.ebay.com/itm/CHRYSLER-DOD...ht_2856wt_1163
When i checked the parts manual for my car, there is AA listed behind the part number. The current part number has AC behind it suggesting/showing that its an updated part. As of now, Dodge has strengthened the shaft dowels to prevent the shearing. we'll see how they work in the long run.
Our cars rocker arms are technically cam followers. these ride along the camshaft directly. I know some people say "lifters" but lifters are only in OVERHEAD VALVE engines where a pushrod is used to push on the rocker arm and in turn the rocker arm pushes down on the valve.
in an OVERHEAD CAM setup, which we have a SINGLE OVERHEAD CAM (SOHC) setup, the cam lobes raise the rocker arm directly and the opposite end of the rocker pushes down on the valve.
The part of the rocker that touches the valve is called a LASH ADJUSTER.
There was one TSB that came out about this: Rocker Arm Lash Adjuster TSB
This was a problem
on a few cars, but ultimately it came out later that the rocker arm dowel pins ARE the issues.
Lash Adjusters sorta serve a similar purpose as a hydraulic lifter would, when oil pressure comes up from the engine being on, the lash adjuster is pressurized with oil in addition to the spring and cap.
When the lash adjuster isnt pressurized properly, or starved of oil pressure, the ticking noise tends to occur. hence this is the case in the rocker arm tick problem
to the problem
is REALLY simple.
The Rocker Arm assembly can be replaced as one entire assembly. shouldnt take most more than 1 hours time. Heres a run through of what i did with the repair. Sorry its no video, just pics, but they are pretty straight forward in the order you will do things and what has to be done. VERY BASIC.
i started the car and used an auto stethescope to listen to which valve cover had the tick noise coming from it.
after turning the car off, and removing the upper intake manifold
then remove valve cover to head with ticking issue. for me it was the passenger side cylinder head.
remove the 10 bolts and lift assembly off the head, replace with new assembly
and torque the bolts down to 31 foot lbs...
After that just reassemble and start the car and drive.
other posts relevant to the issue:
*****Will edit this post with more info as i search through my computer and forum links that i've saved. this is basically a compiled fix from others and own experiences thats in one spot******.