intermediate shat bearings

[e30m20TurbO7]

soo im rebuilding my m20 for the 2nd time , how important is it to replace these, is it crucial , how do you check if you need to replace them . don't really want to go through the trouble of doing this . any advice would be awesome, should i just not worry about it , when i turn the shaft its not very smooth , not crunchy or noisy or anything just doesnt feel as smooth as i think it should . maybe im wrong any opinions

[jlevie]

When clean and lubricated with a light oil (like 3-in-1) the shaft should spin smoothly and not have any detectible side to side motion.

Replacing the bearings is a bit of a bear:


The bearing part numbers are:
11-11-1-280-863
11-11-1-264-196

Measure the IM shaft diameter, chuck the bearings up in a lathe, slow speed,
cut to initial size. Use a standard cam bearing installation tool and install
them in the block, they will crush and become smaller then the diameter of the
shaft. Hand finish with a brake cylinder hone, low speed and a little goes a
long ways. Test fit, finish sizing with green scotch brite. Oh ya, make sure
the front bearing lines up with the oil feed hole from the #1 main bearing
feed (The second bearing does not matter as it is fed through the shaft from
the front journal)

You want about .001-.0015" clearance, I would say .002" max Anything more than
that and you risk loosing too much oil pressure.