Engine

[Slim140]

Shane N. That pic convinced me to spend the money. Where did you get your new bolts? Alot of questionable stuff on the interweb

McMaster Carr

[Glen]

Hi,
IH changed the bolt head markings on Cubs in about the mid 1950's, to the modern style of markings, with 3 or 6 lines going out from the center of the bolt head.
There was the dot in the center, like before, but they have 3 or 6 lines also.

Then in about 1956, they changed to an IH in the center of the bolt heads, and the 3 or 6 lines.
The head bolts on my 1956 Cub have the dots, and 6 lines, which is grade 8.
The front axle clamp bolts have the 6 lines, also. I think all the other bolts on it have 3 lines, which are grade 5.

Below is the torque table from the Cub service manual. It shows the styles of bolt heads at the lower right of the page. The table is from the manual made in the mid 1970's, IH was using bolts with W P on the heads, and the lines.
Every Cub manual I have seen says to torque the head bolts to 45 ft lbs, if you look at the table, the only 3/8 bolt that they say to torque up to 45 lbs is the grade 8, the grade 5 says less torque.

http://www.farmallcub.info/manuals/gss- ... 000-06.jpg

I think that the first several years of Cubs, with the dot on the head bolt heads, and no lines, were probably grade 8, even though it doesn't say. Grade 8 is the only 3/8" bolt in the table above that they say to torque to 45 ft. lbs. I don't know if it's possible to know for sure about the older bolts with only the dot.
Maybe Jim B. and other experts will comment about that.

[Jim Becker]

If you have spent much time in the parts catalogs, you have seen that many bolts (and other standard fasteners) are listed below the part they hold and are called out by the standard description. It may have a part number, which is usually entirely numeric. If a fastener is specific to a certain use, it is identified by an IH part number (D number, R number, C number, etc.) and will not have a standard fastener description.

The original Cub parts catalog identified the head bolts by part number, with no size description. Therefore, they were not standard fasteners. If you look in TC-37F, the head bolts are still listed by part number, the same number they used in 1947. Since the late Cubs seem to have actually been built using standard grade 8 bolts, they evidently decided standard grade 8 was close enough to the originals. I never tried ordering by part number from IH, so don't know what they supplied as replacements.

Keep in mind that the "dot" head means only that the bolt was made by IH. I am not aware It tells you anything relative to modern bolt grading.

[tst]

I have a couple head bolts in the IH package, they are grade 8 bolts

[Glen]

Another question is how do you get the valve spring keepers off without losing them. It's upside down from what I'm used too. I've got some ideas but thought I would float the question to the experts

Hi,
You could use a small magnet to keep them from falling down, but if it doesn't make contact with them, they could drop.
Your hand might be the best way.
You can also temporarily plug the holes in the block with folded rags.

[inairam]

wrap the magnets in a rag and stuff the rag on the bottom of the valve gallery. The first thing you do after you take the valve cover off. you can buy them and they do not do much harm in the pan but you still do not want them in there. The little hat-shaped valve spring seat is harder to find. you do not want to drop one of them in the pan.

[inairam]

I just saw this in a news feed guess it was replated to bolt searches I did on google.

Fast Facts About High-Performance Fasteners

https://www.enginelabs.com/engine-tech/ ... fasteners/

[Jim Becker]

I just saw this in a news feed guess it was replated to bolt searches I did on google.

Fast Facts About High-Performance Fasteners

https://www.enginelabs.com/engine-tech/ ... fasteners/

Reads mostly like an ad for ARP the fastener company.