Bolting the Front Crossmember
 

Hey Guys,
I'm bolting my front crossmember onto my car since I'm not set up to do the correct riveting. I'm using grade 8 bolts with nylon locknuts in every hole where there would have been a rivet (14 total). My question is......Is there anything I should or shouldn't do when bolting my crossmember in? Thought I'd ask y'all since i couldn't find nothing in Andrew's book or by using the search function.

Thanks in advance,

Josh

Re: Bolting the Front Crossmember
 

My advice would be to find a shop to rivet it in.

Re: Bolting the Front Crossmember
 

Before tightening I would ck and double ck the frame for "squareness". I, personally would use regularnuts w/lockwashers WITH loctite. JMO
Paul in CT

Re: Bolting the Front Crossmember
 

Josh,
For what it's worth, I think your way is dandy and stronger than rivets, I'd do the same with a drop of blue Loctite. Loctite just makes me feel GOOD!:D
If I were ever to build another car for dependability, I would replace EVERY castrated nut with self locking nuts, and, OH YES, that little drop of blue LOCTITE! Bill W.

Re: Bolting the Front Crossmember
 

You couldn't go wrong with loctite, lock nut, and lock washer if you are bolting it in.

Re: Bolting the Front Crossmember
 

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.

Re: Bolting the Front Crossmember
 

A friend has a bolted in front crossmember in his '32 Ford and is happy with it. I believe he has counter sunk head bolts on top that have an Allen head socket.

Re: Bolting the Front Crossmember
 

Re: Bolting the Front Crossmember
 

So to muddy up the water a bit, why the need for Loctite? Over time the frame will twist & flex, and just as Marco has said, there will be subtile squeaks ...but why the squeaks? The obvious answer is because the bolts are loose but is it because the nuts backed off, or because the fastener has stretched? My thoughts are that the fastener has more likely stretched but I would like to hear your thoughts.

Re: Bolting the Front Crossmember
 

Since the screws have threads and not solid metal, the threads wear down due to the flexing and produce a loose fit as if a smaller dia. bolt was used?

Re: Bolting the Front Crossmember
 

You probably won't be driving this car every day as it was designed to do, but there's a reason why they engineered rivets in these cars, and I would stick with the original intent if you can. Maybe find someone that can put rivets in for you.

Tommy-

Re: Bolting the Front Crossmember
 

I did one years ago using flat head Allen socket screws,I believe were fine thread along with split l'washers and nuts either 5/16 or 3/8 (don't remember). These are the black oxide strong machine screws and never had a problem with loosening up.

Re: Bolting the Front Crossmember
 

Re: Bolting the Front Crossmember
 

Bolts will never replace rivets. When a rivet is installed, the rivet swells in the hole creating an interference fit. When a bolt is torqued, the stretch actually cause a slight reduction in cross sectional area. That said, the correct bolts will work. Use a fine thread bolt. For a given torque, it has more clamping force and a larger cross section at the minor diameter than a coarse thread bolt. Also, try to find a bolt that has an unthreaded portion to go in the hole. You may have to buy longer bolts and cut them to length to get the correct unthreaded portion length.

Bob

Re: Bolting the Front Crossmember
 

Worry, worry, worry! Most of the twisting & flexing will be absorbed in the length of the frame rails.
Why rivets originally: Probably faster and cheaper, and I doubt they were grade 8.
Don't forget, a number of years back, Ford trucks had rivet problems in the frames causing all kinds of horrible popping and groaning sounds. You can re-tighten bolts, if they ever loosened, but it would be a "BEARCAT" to re-tighten rivets. Yes, I know it's not PROPER, but sometimes we have to be practical. Bill W. Oh! and why Loctite, why not??

Re: Bolting the Front Crossmember
 

I gotta question or two, ....if you have used Loctite on the threads, how you gonna "re-tighten bolts" once it has hardened??

Also, to re-tighten those bolts, how do you gain access to the top of the bolt to hold it while you attempt to tighten the nut when the fender is covering the bolt head? Maybe I am wrong but it don't seem too practical to remove the headlights & wiring, the headlight bar, radiator apron and the fenders just to be able to put a wrench on that bolt head!! Maybe I am overlooking something and if so, I apologize in advance for my ignorance in this.

.

Re: Bolting the Front Crossmember
 

I really don't see them loosening up in normal use.I have taken a lot of old frames apart with bolted crossmembers,I usually have to cut the bolts off.Most seem to have a few original rivets left,so it appears they were rebolted to tighten rather than replace.I did some on A's years ago,but I used bolts with a short shank that almost fit through both layers of steel.I don't know what they look like now,but they are all still being driven.I have a 96 Dodge 3500 with a Cummins in it,it has a two piece frame that is riveted and the rivets are shearing.I have to take it apart anyway as the back of the frame is rusted.I will just bolt the rear section of the frame back on.I use frame bolts,or I believe they are called body-bound bolts.The threads just fit through the holes,but you have to hammer the rest in.

Re: Bolting the Front Crossmember
 

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:D) Bill W.

Re: Bolting the Front Crossmember
 

Interesting.:cool: Never seen these before. Have a link to where you can buy them?

Re: Bolting the Front Crossmember
 

Hey Bill, I thought RED was the strongest:eek:. Have to use the torch to remove it, at least here on the east coast:confused:

Joe,,,

Re: Bolting the Front Crossmember
 

That's what I was wondering 'bout!

Re: Bolting the Front Crossmember
 

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.

Re: Bolting the Front Crossmember
 

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.


.


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.......

.

Re: Bolting the Front Crossmember
 

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

Josh

Re: Bolting the Front Crossmember
 

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?

Re: Bolting the Front Crossmember
 

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.

Re: Bolting the Front Crossmember
 

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

Re: Bolting the Front Crossmember
 

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! :D

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??

Re: Bolting the Front Crossmember
 

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.

Re: Bolting the Front Crossmember
 

Does anyone sell ready made frame bucking bars?

Re: Bolting the Front Crossmember
 

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.

Re: Bolting the Front Crossmember
 

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!

Re: Bolting the Front Crossmember
 

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

Re: Bolting the Front Crossmember
 

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

Re: Bolting the Front Crossmember
 

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

Re: Bolting the Front Crossmember
 

Re: Bolting the Front Crossmember
 

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.

Re: Bolting the Front Crossmember
 

SQUARE IT UP, BOLT IT, WELD IT, DONE1

pAUL IN ct

Re: Bolting the Front Crossmember
 

Re: Bolting the Front Crossmember