Bolting the Front Crossmember

[Leathernek]

Originally Posted by Marco Tahtaras

As mentioned, the top six must be countersunk. This is required for clearance and Allen head type screws are all you can get that aren't junk,

That's what I was wondering 'bout!

[Leathernek]

Thanks guys for all the advice! Yeah, I would still prefer the riveting over bolting but time and money are a factor. Plus I'm trying to get this thing back on the road as soon as possible.

[BRENT in 10-uh-C]

Originally Posted by BILL WILLIAMSON

Loctite comes in a lot of different gripping powers, red, the least, blue, next higher, then there's a green, a purple, and I don't remember if there's more. They even have a "stud & brearing mount" for severe applications. I don't think the bolts would ever loosen, if it did they could be re-tightened with blue Loctite. Multiple screws in my full leg braces always fell out until I put "THE BLUE TO THEM!" (No, I'm not a Loctite Distributor) Bill W.

Bill, we use "242" (Blue) Loctite here in the shop but it is not made to be re-tightened once it has been cured. By serviceable, all that means is someone can use regular wrenches to remove the fastener as it is the lightest in gripping power. Also, I think you will find that their "271" (Red) is actually a stronger in gripping power over their "Blue" and is considered permanent. "Green" is actually the same strength as Blue but it wicks into the threads meaning you do not need to disassemble the fastener to apply it onto the threads. Its use is for already assembled fasteners.


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Originally Posted by Leathernek

Thanks guys for all the advice! Yeah, I would still prefer the riveting over bolting but time and money are a factor. Plus I'm trying to get this thing back on the road as soon as possible.

It is your car and do it as you wish but anyway you go about it, you are going to need to modify the frame or the sheetmetal to make bolts work. Just remember the original holes are ¼" so if you drill to oversize and then countersink the hole, you are speaking of time. If you consider the price of what L-9 'Lamalloy' quality bolts cost, you will likely see yourself spending $2-$3 a piece for them plus the other hardware that goes with them. The rivet set from a vendor would likely cost less than $10 freight & all, so in my mind it comes down to getting a better job at about the same money and for less time using rivets. Your mileage may vary.......

.

[Leathernek]

Originally Posted by BILL WILLIAMSON

Loctite comes in a lot of different gripping powers, red, the least, blue, next higher, then there's a green, a purple, and I don't remember if there's more. They even have a "stud & brearing mount" for severe applications. I don't think the bolts would ever loosen, if it did they could be re-tightened with blue Loctite. Multiple screws in my full leg braces always fell out until I put "THE BLUE TO THEM!" (No, I'm not a Loctite Distributor) Bill W.

Bill, go easy on the loctite! And when you're working with it, be sure that no one slips it in your Kool-aid! (I know a guy that this actually happened to) lol

Josh

[Russ/40]

Never having had an A before, just how much of a problem are bolt heads not flush with the frame rails? How much proud can the bolts be before you run into fitment problems? Aren't the hood shelves on a 29 elevated by the wood blocks beneath them?

[BILL WILLIAMSON]

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Brent & Joe,
Maybe I don't know all my colors right, I use blue 'cause Gregg, (Good kid & builder of my new seats) bought me a GIANT bottle that will last me a lifetime! Besides, whaat do I know, I still got "ROOKIE" tape on the back of my car. Bill W.

[d.j. moordigian]

Russ,
It's the front fenders(first the webbing,then the fenders) laying flat on the
top of the frame rail.....hope that's clear.

Dudley

[BRENT in 10-uh-C]

Blue is likely the best because it offers just a little grip, and it definitely is the best for you since you have a free life-time supply!

Russ, think about the radiator shell and rad. apron. If the fender is up ¼ of an inch, what does this do for the alignment??

[Keith True]

I buy the frame bolts from the Mack garage,they are close by but any truck frame/spring shop has them.Most all I have bought have been 5/8 or 3/4, but I did by some 1/2 inch ones for the Dodge frames.I don't know just how small they go down to.Mack used to say they took a special size reamer to size the holes,but in fact there is a dimension for the hole,it is just a drill size.It is easier to use the reamer,as it is tapered at the beginning and transitions into a straight cut for the last 1-1/2 of it.

[RonC]

Does anyone sell ready made frame bucking bars?

[jerry tocci]

I used the flathead socket for the top and the button head for the rest. Remember, the roads of today and the driving you are going to do is nothing compaired to 80 years ago.

[Fred K-OR]

Originally Posted by Fred K-OR

Josh, I used bolts in my front cross member on my 29 huckster when it was an old beat up CCPU back in the 50's. The bolts are still there and going strong.

When I pull the engine from my 29 coupe I am going to have to replace the front cross member also. I plan to bolt it back in.

Another reason for the replacement of my front cross member is the fact that the rivets and loose in the holes-bolts would not be much worse!

[BILL WILLIAMSON]

Originally Posted by Fred K-OR

Another reason for the replacement of my front cross member is the fact that the rivets and loose in the holes-bolts would not be much worse!

Thought: Some Model A creeking may be caused by tired rivets here and there, nothing is FOREVER!
Bill W.

[Bill Goddard]

Originally Posted by Russ/40

Never having had an A before, just how much of a problem are bolt heads not flush with the frame rails? How much proud can the bolts be before you run into fitment problems? Aren't the hood shelves on a 29 elevated by the wood blocks beneath them?

You can probably get by with about .050" high head in the thickness of the webbing.

[Tim B.]

Leathernek. More options from the peanut gallery. I'm with the Bolts should be fine guys on this one. But with the don't countersink the frame guy's as well. As for head height above the frame a 1/4 inch rivet requires a shop swaged head height of .080 to .170 in and diameter of .330/.430 in for max strength. I suspect this is in line with the original head height. If you don't want to countersink the frame or grind a bolt head down A 1/4-20 ASTM 307 square head bolt has a head height of 11/64 or.1718 inch. Low-Strength Steel—ASTM A307 Grade A bolts have a plain finish, minimum Rockwell hardness of B69, and minimum tensile strength of 60,000 psi. Make sure the frame and crosmember flange mate without a gap. Put a self locking nut on the bolt (without locktite) or a nut & lockwasher and torque the bolt. The danger with overtightening the bolt is you have increased the bolt preload and reduced the yield strength. The additional shock from a pothole could cause the bolt to yield. Over torquing a bolt with lock washer & nut may feel good as well but it negates the effectiveness of the lockwasher. Use the locktight if it makes you feel good but it's easier to take things apart without it. The advantage with the square bolt & nut is you can probably squeak a wrench in and check the bolts if you decide to without tearing things apart. If you end up wanting to rivet in the future the frame isn't countersunk. A bag of 15 bolts is about $6 at McMaster Carr. Tim

[Marco Tahtaras]

There is WAY too much confusion here! Folks are trying to solve problems that aren't even problems! As I said initially it's no big deal. I'll attempt to clarify several points.

1. The top six holes (three on each side) are already countersunk in the frame rails so the rivet heads would be flush with the top surface of the rails. This is necessary whether it be rivets or bolts.

2. As mentioned but not explained, due to the flexing of the frame the load on those fasteners are shearing loads or pressures. That is simply the two adjoining parts wanting to slide in opposing directions. Clamping pressure from properly tightened grade 8 bolts cannot fully constrain that motion the way properly installed rivets do.

Ford went through several iterations in the design and methods early on. For the vast majority of production the punched rivet holes were considerably larger than the shank of the rivets used. However the rivets were red hot in their entirety when inserted and set so the shanks swelled and fully filled the pockets. This eliminated the possibility of lateral shifting at the joints.

3. With bolted joints, once there is circumstance where the shear force is strong enough for one or more fastening points to shift from their initial position (even a few thousandths) it/they will do so again. Each time it will require slightly less force to do so. that does not mean a bolt is loosening or stretching. The slight abrasion will begin to form a path for that motion which will increase over time. As one or more fastening points do this it places more pressure on other fastening points that had previously held steady and the issue begins to spread.

3. Nobody has suggested that good quality self locking nuts will back off so keep the darn Loctite on the shelf!

4. With all this said, there is no scenario where there will be any significant failure. Nothing is going to fall apart! There is not enough range of motion to actually shear a bolt. It's highly unlikely that you would EVER find a bolt that feels loose. All that will occur are subtle squeaks as noted in my first post. It SHOULD take years and/or many miles to reach any level of annoyance and even then, only if you keep other improper squeaks and rattles at bay so this one stands out.

Not a big deal.

[Cool Hand Lurker]

If you put some penetrating oil in the joint after the squeaks start, will it affect the strength of the joint? I don't think so, but maybe I am wrong. But it would stop the squeaks, just like on a leaf spring.

[1931 flamingo]

SQUARE IT UP, BOLT IT, WELD IT, DONE1

pAUL IN ct

[BILL WILLIAMSON]

After all, we're not planning on driving these jewels for 300,000 miles! Bill W's Ghost

[Marco Tahtaras]

Originally Posted by BILL WILLIAMSON

After all, we're not planning on driving these jewels for 300,000 miles! Bill W's Ghost

You are correct. Most folks never drive them 10k miles total so no need to worry about little things like squeaks, rattles, or even minor failures. We won't be around to hear the next owner complainin'!