Engine Work - Update

[Stanton]

are those the correct rod nuts, they should be a locking style nut ? yours looked like a normal nut

Came across this picture of a locking rod nut from another site:

Here's another style:

Which style would you recommend?

If I remember right, mine were just regular nuts. I don't recall any locking features. There were the ones that were on there when I removed them to do the rebuild. I'll double-check, since the underneath side of the crankcase is still open. Now that you mention it, IIRC, there were a couple connecting rod nuts that were very easy to back off when disassembling.

Thanks.

[tst]

the nut on the right in the top pic are good to use

[Gary S.]

How do you get the correct torque reading on a distorted thread nut?

[ricky racer]

I think with proper torque and maybe some blue Loctite, regular nuts will work just fine. I've pulled some engines apart with lock nuts and some without (with no Loctite either) and there never seemed to be a problem.

[Stanton]

How do you get the correct torque reading on a distorted thread nut?

Don’t believe they are distorted. TST just noticed that they didn’t appear to be locking type nuts.

I dropped by Fastenal and picked these up:

They confirmed that Grade C was equal to Grade 8 or better. A 100 count bag, I have enough to do 11 more overhauls!

[Gary S.]

The ones you originally used are not distorted- the ones tst pointed out are. You will not get an accurate torque reading on them. The most accurate tightening method is stretch measurement which is the more modern way of doing things. But I'm sure there is no spec's out there for that. Google loctite on rod nuts for info on that

[Gary S.]

Stanton when the deformed part of the nuts you bought come into contact with the threads of the rod bolt your torque reading on your torque wrench will increase because it will take more force for it to move on the threads. Your torque wrench will think it's now tight when in fact the nut is not up to factory torque spec's. The bearing will not have it's proper crush and can spin. Do some google research. When a rod bolt has the proper torque the bolt will stretch. It is that stretch that keeps the nut from vibrating loose. Even though your 60+ year IHC rod bolts are far from ARP's standards go look on their site and read "fastener tech" https://arp-bolts.com/

[Stanton]

The ones you originally used are not distorted- the ones tst pointed out are. You will not get an accurate torque reading on them. The most accurate tightening method is stretch measurement which is the more modern way of doing things. But I'm sure there is no spec's out there for that. Google loctite on rod nuts for info on that

Well, now I’m confused. Are you talking about the connecting rod nuts? There’s only two per connecting rod. These?

[Jim Becker]

you can come fairly close torquing a lock nut. See how much torque it takes to turn the nut before it contacts the rod cap. Add that much to the target torque reading. Do the first reading on each nut. Don't expect them to be the same.

[Gary S.]

Your talking about using those Fastenal nuts you bought for your rods right?

[Clemsonfor]

you can come fairly close torquing a lock nut. See how much torque it takes to turn the nut before it contacts the rod cap. Add that much to the target torque reading. Do the first reading on each nut. Don't expect them to be the same.

I thought he was talking about the deformed nut will take more effort to tighten.

[Jim Becker]

you can come fairly close torquing a lock nut. See how much torque it takes to turn the nut before it contacts the rod cap. Add that much to the target torque reading. Do the first reading on each nut. Don't expect them to be the same.

I thought he was talking about the deformed nut will take more effort to tighten.

So did I.

[SamsFarm]

What was wrong with the old original nuts?

[indy61]

The parts lookup shows a center lock nut for the connecting rod bolt but I don't know if it matters.
It also states "EXCEPT FARMALL CUB TRACTORS W/ENGINE SERIAL NO. 501 TO 57557 AND 59290 TO 59482"... I don't know what would have been different on those engines.

https://www.mcmaster.com/centerlock-nut ... e~5-16-24/

[Gary Dotson]

While I have no issue with using lock nuts on the connecting rod bolts, it’s really not a very common practice. Mostly, I’ve seen them used on smaller single or twin cylinder engines. Some engines have used the thin sheet metal jam nuts that are installed after the nut is torqued. Connecting rod nuts coming loose are really pretty rare. I seldom use any form of thread locker although I’m not opposed to a bit of lock tite.