784 international rod bearing

[Mmckim]

I put new rod bearings in std size and when I torque them down to proper spec I can not turn crankshaft what is the issue.

 

[teddy52food]

What does the plastigage say? Caps mixed up?

 

[Mmckim]

Caps aren’t mixed up and bearings are standard and standard came out of them.

 

[teddy52food]

Did you turn it over after each one is tightened? Find the tight one to find what is wrong> Did you mike each insert? Maybe one is not standard.

 

[used red MN]

Sorry if this is common sense engine rebuild knowledge but you are asking. Are the caps installed in the right direction, as in the bearing location tabs are both closest to the same rod bolt? How do the new and old bearing shells micrometer measurements compare? They may be boxed wrong. It was a running engine before no serious damage that may have caused a bent rod? And the crankshaft is what was in the tractor or is it a replacement?

 

[rustred]

I put new rod bearings in std size and when I torque them down to proper spec I can not turn crankshaft what is the issue.

you are asking for a miracle by not giving any info on what u have done. what is your old brg gap measurements ? what is the new brg. measurements? check them with plastigauge. is this the original crank? or has it been turned? have u checked each rod after torquing it for crank rotation? did you loosen them up and see if the crank turns.? .002 under brgs will cause that also , the brgs. can be wrong . you have alot of checking to do. i have no idea if this is your first engine job, or your experience. so with a one sentence question you wont get much of an answer without providing some information. back in 1974 when i was 17 years old i decided to put ring sin my 67 gmc 1/2 ton, 250 cid , went to the gm dealer and asked for rod brgs. the parts man said how many miles u got on that engine. it was around 100k. he says well u need .002 brgs then. how would i know any different. took them and installed them torqued the rods and engine would not turn over. pulled them out , took them back to the parts man and said my engine will not turn over with these brgs. so he gives me standard brgs in replacement. put them in and all was good. this is my example of me being young inexperienced.

 

[Janicholson]

Caps aren’t mixed up and bearings are standard and standard came out of them.

Unless the crank's rod journals were measured with an accurate/calibrated real micrometer, guessing the size of an insert, or the clearance is just a pathway to grief. Plastigauge is not guessing, and if it won't turn is is for sure wrong. Invest in, or borrow an appropriate "C" shaped micrometer with a calibration standard. Watch a video on both the measurement, and the use of plastigauge before going forward. Jim

 

[Mmckim]

Bearing set came with 2 .010 oversized bearings. Packaging mess up

 

[Fritz Maurer]

That’ll do it…

 

[Janicholson]

Bearing set came with 2 .010 oversized bearings. Packaging mess up

Those are actually undersize inserts. The journal is smaller for them. and correct term is undersize. Not a flame. Jim

 

[used red MN]

Bearing set came with 2 .010 oversized bearings. Packaging mess up

Better have someone with the proper equipment check that rod end ID to make sure it is not distorted after torquing down on the wrong size bearings. At least plastigauge, and check it for being free to move side to side freely after final torque down. Side to side within the crank pin side flanges, as in front to back if the engine is installed.