Rod Bearing installation problem, need help!

[Irish Pride]

Need some help guys, I'm at a loss right now.

I'm in the process of changing the rod bearings on my 89. All the old bearings looked great. The number 5 cylinder showed more wear than all the others but none of them showed any copper. I'm only changing them because I've had the car 4 years now and didn't know the history on the build. I easily could have gone several more years looking at the old ones though.

I started this last week and I still have not been able to finish it. When I torque the number 3 cylinder rod cap it completely locks up the crankshaft. Locks it to the point that I cannot turn the crank with all my strength. When I loosen the nuts on the number 3 cylinder rod cap the crank frees up and I can easily rotate it with my breaker bar. Has anyone ever run into this problem? I've got the plug out of that cylinder so there is zero compression on it.

I thought that maybe the new rod bearing was misboxed and possibly oversized so I ordered some new bearings from rockauto and the new new bearing is doing the exact same thing. What could be going on here?

This is the new bearing after being installed and me trying to rotate the crank .

 

[sperold]

Any chance the rod caps are mixed-up? I know it sounds impossible as they are numbered and maybe have arrows, but something is wrong that has been caused by disassembling only. A mix-up always involves 2.
Put the old bearing back in and see if you can turn the crank.
Use some old fashioned plasti-gauge and see if shows this 0 clearance situation. But do it last, and watch for one rod to be very loose in the first 5 that you do.

The oversize bearing exercise that you followed could still be a possibility. What we have not been told is whether this is the first cap you have tightened. If it is, then there is a good chance the bearings are mis-labelled.

At this late stage in the game, the standard size bearings are the most in demand and are likely gone. That leaves, in the supply chain, all the bearings that have been dry fit and returned, as they are mislabeled.

Very much a long shot, but that is all there is left. Time to get a micrometer to do some comparing.

 

[rubydist]

the only time I've seen this symptom is if the bearing tang is not fitting into the notch on the rod or cap correctly. it could be something in the notch, or it could be the tang is too large (unlikely if multiple bearings have the same symptom) or it could just be miss-assembly. from the wear marks on the bearings in the photo, it looks like the bearings were tipped on the cap/rod, which would bind it up.

of course, as sperold points out, the bearings could all be the wrong size.