Engine - Coding System to Match Bearings to Crankshaft
90nissan02Classification: Section:
EM90-002 Engine Mech.
Reference:
TECHNICAL BULLETIN NTB90-011
Models:
All 1987-90 Models
Date:
February 15, 1990
IDENTIFYING CRANKSHAFT BEARINGS FOR SERVICE APPLICATIONS
APPLIED MODELS: All 1987-90 Models.
SERVICE INFORMATION
Beginning with engines manufactured in 1987, Nissan has utilized a coding system to precisely match bearings to the crankshaft. Certain ways of marking/coding the crankshaft have varied. The purpose of this bulletin is to explain those coding variations so that the correct replacement crankshaft bearings can be selected.
Some Crankshafts utilize marks on the No. 1 Counterbalance. There may be one or two rows. If there are two rows, the top one identifies the grade for the main bearings; the bottom one identifies the grade for the connecting rod bearings.
If there is only one row, it will indicate the grade for the main bearings and the engine rebuilder should use the "standard" bearings for the connecting rod application.
NOTE: Some Crankshafts were additionally marked on the No. 5 Counterbalance. In this application, the marks on the No. 5 Counterbalance represent the grade for the connecting rod bearings and the marks on the No. 1 Counterbalance represent the grade for the main bearings.
One other variation in Crankshaft marking is the use of horizontal scribe marks on certain Crankshafts and Arabic numerals (1, 2, 3, etc.) for others.
^ Those Crankshafts graded with Arabic numerals need no interpretation because their grades directly correspond to the Parts Microfiche and Service Manual for the respective vehicle.
^ Those Crankshafts graded with vertical scribe marks can be interpreted by using the following table.
Crank BRG. Counterbalance "vertical slash"
Grade Grade #
0 no mark
1 I
2 II
3 III
Refer to the "S.D.S." chart at the back of the EM section of the appropriate Service Manual for bearing color code application.