[elefantrider]

Only can find 4, but it calls for 6. Anyone have 2 extra laying around.
Look like this:

[tom s]

Chris,I dont think it is a big deal to swap them out for 6 of aftermarket correct thread and strength.I know I have some in my drawer that work.The reason I know is I lost 2 for awhile and put 2 diff ones in.Tom

[elefantrider]

Ropeshaft became disconnected after only 10 min at idle! Heard a loud bang and looked underneath to find 4 bolts on the floor. They were as tight as I could get with a ratchet and the limited space. I guess not tight enough.

[tom s]

Chris!They HAVE to be TQed to spec!ASK me how I know!That is how I lost 2,they came out and went back in the tube.I TQes them to spec and repaced with 2 others untill I pulled the tube and ound them.Tom

[tom s]

That might be where the other 2 are!Tom

[c5farmer]

Looks like your bolts are toast. Spec new ones, add locktite, and torque to spec. I think around 45 ftlb.

[tom s]

35 lb,it's tight in there to do it and it wants to rotate while your doing them.Tom

[GaryK]

Hi Chris,
I should have an extra set of 6 for you. Will check tomorrow.
Gary

[tom s]

Chris,I have to go to Brea in the AM,can meet you up that way with a set that will work.Will be leaving LB about 8:30,let me know.Tom

[elefantrider]

Hand tightened with a ratchet, probably got to 30lbs. Was not loose.
Will use a torque wrench next time and 40+lbs.

I could not believe how soon they came out. 5-10 minutes of running, maximum!
Will see if Fastenal has any grade 8. Need to get this thing running this weekend.

I see that 1-2 of the crankshaft threads are a little buggered up now. Might need to run a tap through them.

Locktite is a great idea. Will try the blue first.

[wojo1963]

If you go to fastenal you will be able to buy sae grade 9 bolts. These are highest strength available about 180000 psi. If for some reason they are not available you can use grade 5, which are the next highest strength
Look at the existing Bolt head if there three lines 60 degrees apart, that is a grade 5. If you go to the fastenal information. Section there will be charts with info for all bolts. Second do not use loctite on torqued specified bolts. Some one years ago calculated how much force would be needed to develop the preload in each Bolt needed. If you put on locktite, you may not reach that preload and the two surfaces will not be properly mated to perform their function. Torque values are calculated for dry clean surfaces. They knew home to put things together 50 years ago. The engineers did need a "computer program" to tell them how, they went in the shop and did it.

[elefantrider]

Got the grade 9 bolts and bought the remaining box full so have spares if they fall out.
I used red locktite, and torqued to 45ft-lbs which is not a lot but requires you to lock the starter ring with a screwdriver. Engine begins to turn at 35ft-lbs of torque. What is the factory torque value on these?

I did not wait for the loktite to dry before driving.

[elefantrider]

For some reason, when the original bolts backed out and the ropeshaft let loose, it sprung so far back that the original legth bolts would not reach. I had to use a longer bolt to pull the shaft back to the crank. Many four letter words were said before i ran to the store to get a longer bolt. Even afterwards as it takes a lot of effort to lift the shaft into place, and it always wants to rotate around, when not located by the center hub. Impossible to pull forward by hand!

[tom s]

Factory bolts called for 35

[elefantrider]

Glad I used 45 with the locktite. 35 seemed like just a little more than finger tight.

[JohnFromVentura]

If I remember bolt markings correctly, grade 7 bolts (~150,000 PSi) have 5 bars on the head, grade 5 bolts have 3 bars, grade 3 and butter bolts have no bars? As a reference head bolts are grade 7 ... grade 5 bolts are more than enough for most applications. Never heard of a grade 9 but they probably exist?

[tom s]

it was the correct yield for the factory style bolts to require no lock washers or lock tight?Engineers do thing for a reason!Tom

[Bill Hanlon]

I'm no mechanical engineer, but it would seem to me that changing to a higher tensile strength bolt and tightening it to the higher rated torque without changing the material that the bolt threads in to may not be a smart thing to do. You may pull the threads out of the "nut" (in this case the crankshaft flange) because it might not have the same strength.

Just an uneducated thought.

[elefantrider]

Those crank threads are tuff. After my factory bolts all backed out, there was no damage to the crank threads. Look at my photos of the damaged factory bolts. I am not too worried about 45 ft lbs in them. Rods get as much. Hardware grade 5 offshore bolts quality are all over the place. The grade 9 bolts were the only ones which matched the large head size of the factory bolt. And had a rolled tip.

[elefantrider]

I have done some research on how Locktite affects torque values, it seems it does not. In hindsight, 35-40 FT-Lbs would have been an adequate torque. With Red Locktite, they should not back out if left to set 24 hours to cure.