Engine Roller Tappet - Improved Design
90chrysler12NO.: 09-05-90
REVISION A
GROUP: ENGINE
DATE: Sept. 24, 1990
SUBJECT: Tappet Noise - 3.9L, 5.2L And 5.9L "LA" Engines
MODELS: 1985 Through 1990 ALL VEHICLES EQUIPPED WITH 3.9L, 5.2L, AND 5.9L "LA" ENGINES EQUIPPED WITH ROLLER TAPPETS.
THIS BULLETIN SUPERSEDES TECHNICAL SERVICE BULLETIN 09-05-90 WHICH SHOULD BE REMOVED FROM YOUR FILES. THE MODEL YEAR/VEHICLE APPLICATION THAT THIS BULLETIN APPLIES TO HAVE BEEN CORRECTED. ALL CHANGES ARE INDICATED BY ARROWS.(-> <-)
DISCUSSION
Figure 1:
Beginning in May, 1990 a new improved roller tappet entered "LA" Engine production. The tappet oil feed hole was rotated 90~. The oil feed hole now faces up and can be identified by a paint mark on the tappet as shown in Figure 1. This improvement will allow more oil to be retained in the tappet, resulting in a reduced engine start-up noise.
The new tappets may be used on earlier engines equipped with roller tappets as indicated in the chart on page 2.
Engine Model/Year Old PN New PN PN Includes
5.2L Car/85-88 4494467 4636794 Tappet, Push Rod, And
3.9L Truck/88 Instruction Sheet
5.2L Truck/88
3.9L Truck/89-90 4387682 4636790 Tappet And
5.2L ->Car/89<- Instruction Sheet
Truck/89-90
5.9L Truck/89-90
When installing the new tappet the oil feed hole must face up as shown in Figure 1.
Policy: Information only.