2010-04-11
Re-Work Alignment of the Balance Shafts on the 1993 Honda Accord Wagon
Since the last timing belt change ten days back I felt a "tingle" vibration in my feet at 3000RPM. The vibration didn't lessen in the 1200 miles since the work was performed so I had a suspicion that at least one of the two balance shafts was out of sync. Today I disassembled the car to the point of performing a timing belt change so that I could check, and if needed, adjust all belt alignment items.

The timing belt (crankshaft to camshaft) alignment was suspect but after double-checks looks to be correct. The front balance shaft was off "one tooth". I hoped the back balance shaft would be in alignment once the front was changed, but no, the back was out a different amount.

These top photos document the final settings while two bottom photos show the out of spec balance shafts.


Engine crankshaft Top Dead Center for cylinder #1 alignment marks.



Camshaft pulley with "forward" alignment mark - flat to the head's top machined surface



Camshaft pulley with "rearward" alignment mark - mostly flat to the head's top machined surface
(difficult angle to get a good camera shot).



Front balance shaft. Alignment marks now aligned.



Rear balance shaft
The shaft is in alignment if a 74mm depth shaft fits into the hole to the sealing surface.
With a 2am test drive complete I know the 3000RPM tingle in my feet is gone. With the last photo taken at 10:24pm it's taken me right about 3.5 hours to reassemble the vehicle. One task scratched off my ToDo list.

Before the alignment procedures were performed, this is what things looked like:

Front balance shaft - out of alignment



Rear balance shaft - out of alignment - 74mm shaft not fully accepted into the inspection hole.