Flywheel bolt, nut and washer question

[lonejacklarry]

 I just installed new bolts in my 230 truck flywheel.  I cannot tell from the shop manual whether or not to use flat washers on the bolts.  Part 2 of the question has to do with the nuts.  Are they simply a grade 8  7/16-20 or a thinner nut?

 

Thanks.

[wayfarer]

Standard nuts. The oem used an internal tooth washer.

[lonejacklarry]

Great.  Thanks for the quick response.

 

[TodFitch]

1 hour ago, wayfarer said:

Standard nuts. The oem used an internal tooth washer.

Maybe the car side is different: I don’t see any lock washer of any kind in the 1936-48 Plymouth parts book. And the bolts and nuts are numbers not found in the standard parts list so they aren’t just “standard nuts” though I don’t know how they differ. Since most nuts and bolts in the standard parts list were grade 0 or 1, it could just be the flywheel hardware was more equivalent to modern grade 4 or something. But that is just a guess.

[Los_Control]

Not sure if this helps .... Just showing what Ford did in 1951.

 

The bolts going to the fingers are grade 8 fine thread and flat washers.

The bolts going to the flywheel also grade 8 but uses lock washers.

 

Just saying a lot of pressure here and you want it right.

 

 

[Dodgeb4ya]

Here are pics of the flathead flywheel bolts/nuts with groove/notches around the perimeter and factory external tooth star washers..grade five or higher... 7/16" X 20.

Torque I think is 55lbs.

Edited September 28, 2021 by Dodgeb4ya

[kencombs]

I have the nuts from different flywheels/cranks laying around.  All the nuts look like those pictured.  But, they are a little bit thinner than the generic ones in the bin at the parts store.  Maybe a hardware brand thing.

[Dodgeb4ya]

Those crank bolts are not overly long...that's why the slightly thinner special nuts I suppose and for clutch plate clearance too.

Edited September 28, 2021 by Dodgeb4ya

[kencombs]

17 hours ago, Dodgeb4ya said:

Those crank bolts are not overly long...that's why the slightly thinner special nuts I suppose and for clutch plate clearance too.

And they help provide wrench clearance.   It’s kind of tight up there. 

 

Edit to add:  If my memory is right, the other difference is in the wrench size.  My flywheel nuts are 11/16, while the standard for a 1/2 thread bolt is 3/4.

Edited September 28, 2021 by kencombs

[Dodgeb4ya]

2 hours ago, kencombs said:

And they help provide wrench clearance.   It’s kind of tight up there. 

Yeah it is tight...I forgot about that..and I have and use the special thin long wrenches to tighten those crank nuts...especially the FD and torque converter nuts on the Powerflite/Torqueflite converters.?

[lonejacklarry]

Thanks for the information.  I got the flywheel mounted today after I got some 7/16 star lock washers from Fastenal.  I had to buy a sack of 25 so I have a lot left if anyone is interested.

 

[JBNeal]

These small items are tricky getting ordered these days...I've stalled on several projects because of the non-negotiable 15 buck shipping fees from vendors that could ship in a small padded envelope for 5 bucks 2 yrs ago, it's like they want to make up for lost sales from last year or sumthin'ruther ?