Nemo02Z

Got a question but not sure where to go to ask so here we go. we have a 97 4.3 motor out of a gmc pick up, stupid us we did not mark the rods when we dropped them out of the motor, no big deal we thought, now that we are putting them back in we get them in torque them down to about twenty pounds or so and the crank will not turn over locked tight. we know its not the crank, we thought it might be at first so we got another one, now question is this, theses rods have gma and gmb stamped on them is there a certain order they have to go in or do you think that since they use heat to put the piston back on the rods they warped the rods.

Adrenaline_Z

I bet you have the non chamfered side of the rod backwards and it's binding
on the crank.

Look at the big end of the rod and you'll see one side is machined. The chamfered
side goes against the counter weight.

Nemo02Z

Okay I will look at them. what about the rod caps not being put back on the exact rod the came off of....

Adrenaline_Z

Not unless the cap is installed with the chamfered side reversed (which would
be easy to see).

Have you installed new bearings and clearanced the bottom end? Did you have
the connecting rods checked and machined as necessary before installing them?

Nemo02Z

Yep most parts are new the block just came back from the shop so clearances are good, for the most part we know it has to do with the rods and since nothing was labled we are gonna have to go at it by trial and error, and keep switching rods and caps. which with the info you gave me it will be easier. thanks

Nemo02Z

Thanks for the info we finally figured this out,we were putting the caps on the wrong rods, since they were noy labeled when they went to the shop, we had no idea which ones went on what rods so when we torqued them down they were binding. stupid mistake will not happen again....
Thanks again

Adrenaline_Z

Nice, thanks for the update. Good to see it was nothing major.