Remove the valve cover and rotate the camshaft so that the base circle of the cam is against the follower intended for removal. If equipped, remove the retaining spring from the cam follower. Using special tool T74P-6565-B or a valve spring compressor tool, collapse the lash adjuster or depress the valve spring as necessary, then slide the cam follower over the lash adjuster and out from under the camshaft. For installation, reverse the removal process, ensuring that after any procedure requiring removal of the rocker arms, each lash adjuster is fully collapsed after assembly and then released before turning the camshaft. For the 2.2L Diesel Engine, remove the valve cover, then the bolts attaching the rocker shaft to the 
Cylinder Head, and remove the rocker shaft. If necessary, remove the pushrods, noting their positions for reinstallation. Install the pushrods with the ball end toward the tappet, position the rocker shaft on the cylinder head, and install the retaining bolts, ensuring the rocker arms are fully seated in the pushrod cups before tightening the bolts alternately from the center to the ends. Adjust the valve rocker arms and install the valve cover, connecting the heater tube assembly, then run the engine to check for oil leaks. For the 2.3L Diesel Engine, follow a similar process, ensuring the rocker shaft is installed with the oil holes down and tightening the bolts to 25-28 ft. lbs. For the 2.8L and 2.9L Engines, remove the valve rocker arm covers, loosen the rocker arm shaft stand attaching bolts, lift off the rocker arm and shaft assembly along with the oil baffle, and disassemble the shafts by removing the spring washer and pin from each end. Mark parts for reassembly, and if necessary, remove the plugs from each end of the shaft. When assembling, ensure the oil holes in the rocker arm point down, install plugs if removed, and lubricate the assembly with engine oil. Install the oil baffle and rocker arm shaft assembly to the cylinder head, guide adjusting screws onto the pushrods, and tighten the rocker arm stand attaching bolts to 43-50 ft. lbs., adjusting the valve lash to the specified setting. For the 4.0L Engine, remove the rocker cover, loosen the rocker arm shaft stand bolts until free, lift off the rocker arm shaft assembly, and if pushrods are removed, tag them for correct reinstallation. Reverse the removal procedure for installation, tightening the rocker arm shaft bolts to the specified torque of 52 ft. lbs. before reinstalling the rocker cover.