Replacing the rod bolts

Bkpigs · Nov 28, 2015

Doing an in frame on a Farmall 504. How many of you replace the rod bolts and how many just re-use? Also, this tractor doesn't have a lock ring for the bolts. Would you suggest using loc-tite or will the torque hold it in like before?

Thanks in advance.

gene bender · Nov 28, 2015

Torque has held tham since new so they still should.

RBoots · Nov 28, 2015

Is that a diesel 504? If so,
I would highly recommend
replacing the rod bolts in
the D166/188 engine.

Ross

Tx Jim · Nov 28, 2015

Using new rod bolts when replacing brgs is a lot cheaper than replacing a cylinder block with a hole in it.

Russ from MN · Nov 28, 2015

If the replacements are made in china I would re-use the old ones!

Steve@Advance · Nov 28, 2015

If it's a gas engine, doing an inframe, I would go back with the old bolts and nuts. No locktite, just
clean everything up, oil the threads, torque to specs.

When torquing, you will feel the bolt come into torque. If it continues to stretch, not come up to torque,
or binds up before it pulls tight, there is a problem.

I've put many, many engines back with old bolts, never had a failure I could blame on a bad bolt. For a
more serious, complete rebuild, or performance build, then the rods get reconditioned with new bolts. You
don't take the bolts out once a rod has been reconditioned, it will change the shape (I tried it). So
wouldn't the same apply to an old rod?

If there were a rod bearing failure, then the rod will need to be reconditioned. But then the crank will
need to be corrected, so that rules out an inframe.

GlenIdaho · Nov 28, 2015

I don't have an Farmall, but when I rebuilt my engine in my Ford 850 one did not feel right when torquing, ended replacing all. As was said, although mine were about $5 per bolt, still cheaper than a ruined block.

RBoots · Nov 28, 2015

The bolts for a D166, D236, and D282 IH diesels are about $14 each. I have a D282 here getting a rebuild. Almost $175 just for the rod bolts, but better safe than sorry with those engines.

Ross

Steve@Advance · Nov 28, 2015

Agree! I don't know where Mr. Gasket bolts are made, but about 25 years ago we were building a SB 400 for a dirt track racer. Bought a set of main bolts, went to torque and they just kept turning, wouldn't come up to torque. Pulled a couple out, they were stretched! Got obviously longer and thinner!

Trashed them, went with another brand. No problems. For ever after Mr. Gasket was then known as Mr. Casket! LOL

CenTex Farmall · Nov 28, 2015

The bolt is like a spring. The torque spec for a particular size and material of bolt will make it stretch but not permanently deform it. This preload is what keeps it from loosening up.

We replaced bolts on a Super A build recently because they had corrosion pits on the shanks and it was unknown how many times that engine had been into before.

RPM rather than power is what stresses rod bolts. Tractors are pretty safe in this area due to the low rpm so you can usually re-use if there is no corrosion or thread damage. There are some engines though where it's recommended to change them at each build.

If you think the engine has seen a lot of hours and multiple rebuilds then it's safest to replace them. You also don't know what the last guy did when it was apart.

Janicholson · Nov 28, 2015

I second this motion. (Centex's) Jim

Replacing the rod bolts

Bkpigs

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gene bender

Well-known Member

RBoots

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Tx Jim

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Russ from MN

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Steve@Advance

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GlenIdaho

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RBoots

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Steve@Advance

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CenTex Farmall

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Janicholson

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