Recipe - Ram 6.4L HEMI Gasoline (Ram HD 2019+)
Specific Fix build
Reliability tier: verified - verify before ordering, see /disclosure/
Lifter/valvetrain repair for the 6.4L HEMI (mode Lifter / cam wear (HEMI tick source #2)): the 6.4 HAS MDS - deactivating lifters (5038788AD) sit beside standard ones (5038787AD), and a failed deactivating lifter reads as a cold-start tick plus an MDS DTC. Match the lifter type to the position; renew pushrods/rockers as inspected; valve cover gaskets are single-use.
Parts
- 6.4L HEMI Hydraulic Roller Lifter, standard yoke (OEM) - standard hydraulic roller lifter (5038787AD) (qty 1)
- 6.4L HEMI Hydraulic Roller Lifter, deactivating (MDS, OEM) - MDS deactivating lifter (5038788AD) (qty 1)
- 6.4L HEMI Push Rod (OEM) - push rod, renew as inspected (68447792AA) (qty 1)
- 6.4L HEMI Rocker Arm (OEM, per position) - rocker arm per position (5179087AB) (qty 1)
- 6.4L HEMI Valve Cover Gasket (OEM) - valve cover gasket, single-use (5114179AB) (qty 1)
Install order
- confirm the cylinder: tick timing + MDS DTCs; a deactivating-lifter fault shows on the MDS side
- match the lifter TYPE to the position - standard vs deactivating are different parts
- inspect and renew pushrods/rockers on the serviced side as required
- single-use valve cover gasket on reassembly; fresh oil before first start
Expected outcome
Quiet valvetrain, no MDS DTCs, stable oil pressure.
Do not
- never mix standard and deactivating lifters by position
- do not run the engine after metal contamination in the valvetrain oiling
Parts budget
About $25-$350 in parts. It depends on what the diagnosis finds; each option below is what you buy together. Prices marked "at Dave's" are Dave's Auto Center's, the same as in his store; the others are approximate prices from OEM and maker catalogs, rounded (a manufacturer's list price can run higher). Parts only, no labor.