Another bolt question

JohnRowehl · Jul 22, 2020

77 RC. This is one of three that holds the stay rod pivot support. No grade markings. No lock washers were used with it. I presume that the holes in the heads were to thread a wire through them to interlock them instead of using lock washers. Just wondering why. Also seemed odd to me that bolts used there were not of a harder grade. Any insight?

oliver90owner · Jul 22, 2020

I would simply expect they were of adequate strength for the duty.

Perhaps wiring, to prevent coming unscrewed was more the norm, back then? Engine crank bearing cap nuts were wired, as well - rather than
having split pins to secure the castellated nuts - on earlier engines. Perfectly adequate.

There is also less likelihood of the wire being used a second time - tab washers can be a pain, if re-used. One size needed on a roll of wire, for
most applications, instead of different sized tab washers for different diameters?

Maybe you need to look at/investigate the loads applied at the pivot? Those forces may not be as great as you might be suggesting.

Several reasons, might be more. Take your pick. Personally I reckon the design engineers knew what they were doing, so I don’t try to over-
think these issues.

JohnRowehl · Jul 22, 2020

(quoted from post at 13:51:16 07/22/20) I would simply expect they were of adequate strength for the duty.

Perhaps wiring, to prevent coming unscrewed was more the norm, back then? Engine crank bearing cap nuts were wired, as well - rather than
having split pins to secure the castellated nuts - on earlier engines. Perfectly adequate.

There is also less likelihood of the wire being used a second time - tab washers can be a pain, if re-used. One size needed on a roll of wire, for
most applications, instead of different sized tab washers for different diameters?

Maybe you need to look at/investigate the loads applied at the pivot? Those forces may not be as great as you might be suggesting.

Several reasons, might be more. Take your pick. Personally I reckon the design engineers knew what they were doing, so I don t try to over-
think these issues.

All makes sense. And indeed they have withstood the test of time for 70 years.

J. Schwiebert · Jul 22, 2020

My neighbor had a very early 77 with a wide front as he grew tomatoes. I had that front end off and I don't remember any bolts being wired.

alberta dave · Jul 23, 2020

In regards to the strength question, I might have told this story before, but I can recall having trouble with a tandem front steering box constantly breaking the mounting bolts on a service rig.
Couldn’t figure out why our high strength 7/8” gold coloured bolts kept breaking. Sure enough we got out in the boonies and ran out of high strength
bolts and were forced to use standard bolts in their place. We pulled over every 5 miles or so to check but the lower grade bolts were holding. 5 miles
turned into 10 mile checks and once we found a paved road we headed straight for the shop. Turned out the lower grade bolts were stretching And
returning to shape but when the high strength bolts did the same thing they cracked due to their higher hardness.
I went to tighten up what I thought was a loose bolt on the drawbar mount on an 1850 yesterday and it twisted right out. The bolt has that bronze/gold
finish and not black oxide or silver. I have to assume it is a similar type failure. That’s gonna be tough one to extract.

greg krush · Jul 23, 2020

Not so much about strength of the bolt, front main engine seal leaks, drips down on pivot, bolts come loose, cant keep them tight, so use wire. simple
engineering.

gary66 · Jul 23, 2020

harder isn't always better. Harder snaps, softer stretches. Back in the day they didn't try and save a penny on a bolt, if a 3/8 worked a 1/2 was better.

I like the way things used to be built. If they could only combine new technology with old building practices.

gary66 · Jul 24, 2020

just to add...implements that use sheer pins like brush hogs use hardened bolts because they snap right off. A softer bolt would just bend being of no use at all.

Another bolt question

JohnRowehl

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