Frame Rivets question?

[Harper]

I am down to the point of taking my cab off, down to the frame,...so why would I want to take the frame Rivets out that hold cross memebers, body mounts etc? and even better question how do you replace those to make them look factory? or would you just replace them with new bolts? which is stronger?

[rickairmedic]

Harper I have never known anyone yet to remove crossmembers or body mounts in a resto ( unless they were switching to newer drivetrain and needed room for the tranny ) . Then usually only the crossmember that is blocking the tranny is removed and the new one is bolted in .


Rick

[ICEMAN6166]

only time i have removed xmembers is because of damage, including spring brackets. i always replace with grade 8 bolts of the next size larger as specified in the factory shop manual. the rivets are between sizes
example= rivet bigger than 3/8" so a 3/8" bolt is sloppy in the hole, drill to 7/16"

[Harper]

thanks...I will soon be blasting my frame, and didnt know how far to take it down...It has lasted 47 years the way FORD built it, however after blasting and epoxy primer, I am hoping my grand kids will be able to enjoy it in another 47 years

[Total Gearhead]

I remove everything on the outer frame. then have it blasted spray it with epoxy primer and replace with grade 8 next size up. I live in the rust belt so if I leave everything on and just blast the rust will crawl out from behind the brackets and all my time is lost when it starts to look bad. I only like to do things once. If you do not have it powder coated then it's best to paint it with epoxy!!! It will last forever if done right! Oh and I guess I should mention... when it comes to paint I am extremely anal.

[Toyz]

Generations ago, Ford stocked the 7/16-20 x 1 1/4" "Body fit"bolts for this purpose. It's pretty hard to find 7/16" body fit bolts with just the right amount of unthreaded "shank" to avoid thread contact inside the drilled hole. I would expect they are still available. Old, and I mean old, p/n was 20431-s8 (B186). Thread contact on the transmission c/ member is probably not a problem; I don't know if I would accept it on other components such as suspension brackets and crossmembers.
It's a real PIA to remove all attachments, drill and replace; but as TG mentioned, it's the right answer. I certainly would invest in an air chisel (hammer) gun and an assortment of chisels. If you aren't building an absolute show truck, I wouldn't be concerned enough to remove unless needed for other modifications.
Paul

[foodstick]

Harper, I think this subject might have came up about the Crew cab that had to change transmissions at SS5.

The problem was the tranny had either been installed from the front, or with the cab off. And the unit wouldn't come off from underneath, and then those pesky rivets on the stock mount had to be removed.. removed in a BAD position for the removee...

[Max]

Factory rivets drill out pretty easily.

[Total Gearhead]

Factory rivets drill out pretty easily.

what he said

[62bigwindow]

I removed all of the spring,shock and cab mount brackets and used 1/2 x20 grade 8 bolts and top lock nuts on my frame.I didnt remove the cross members because it looked to be a pain to put back in.I also should mention that I found a few surprises in the form of rust behind some brackets that needed attention.

[PFM-64f100]

Do your self a favor now and pop out the tranny crossmember rivets. This way you won't be doing this if you have to pull the tranny one day.

We used grade 8 bolts to bolt the crossmember back in.



When I got the truck back to texas and had to pull the tranny again it was a lot easier to say the least.

[Harper]

thanks yea, I had issues putting in the 302 with late 90's 5-speed before i decided to remove everything... my air chisel isnt so great, and the way i have removed even bolts is with a grinder...simular to the above picture...heck I didnt know there was any other way but the hard way lol

[4 Baja]

Great information above, here is my experience:
I've taken many rivets out over the years using many different methods. I usually end up having to use more than one way to complete the job.

One way is to heat the rivet with a torch until glowing orange, then cut the rivet head off with the air chisel, then punch it through. It works fast if you are doing a lot of them.
The problem is, the air chisel can jump around and gouge up the parent material, and sometimes the hot rivet head ends up where you don't want it.....ouch!

The other way is to grind the heads off, then punch them through. This works pretty fast too as long as there is enough room for the grinder.
The problem I have found with this method is sometimes the parent material was made concave from the riveting process so it's hard to grind the head off flush.

The process I use most of the time, is to center punch the rivet. Then using cutting fluid, drill it out working my way up using something like an 1/8", 1/4", 3/8" on up to 29/64" for a close fit on 7/16" bolts.
This way takes the longest but is the cleanest way without gouging up the frame, crossmember or bracket. If there is no room for the drill to work, I resort back to one of the previous methods.
I have noticed that some rivets are softer, some harder. I think maybe there was a higher grade rivet for suspension brackets versus a cab mount for example.

To bolt the parts back together, I use grade 8 bolts, grade 8 flat washers and grade 8 stover lock nuts or grade 8 stover flange nuts if they have them. 7/16" hardware seems harder to find sometimes.

Hope that helps.

[Toyz]

A 1'' wide air chisel bit is my tool of choice. The straight ones with a thin profile work best, but require more sharpening. If obstructions exist, and they always do, a 30 degree shank chisel works well, although not as fast or efficient as a straight shank. A 45 degree is worthless IMO. Heating helps if you encounter a particularily resistant rivet. Several people at Dean's suggested grinding a cross on the rivet head, then hand chiseling them off. This seemed to work, but again, obstacles can make that method impractical. I've got cheap air chisels, and then I've got an ancient Snap-on long-barrel. Guess which gets used on frame rivets. 100+ psi air supply, oiling the air tool, and minimizing the amount of air supply line is also an important part of the equation.
7/16" grade 8 hardware IS somewhat harder to find, but is commonly used on industrial and agricultural equipment. Body fit bolts are a much better choice, IMO, and are readily available from industrial suppliers such as Motion Industries, and as a last resort, Fastenal, if you can find a co-operative salesperson. As another, more expensive, last resort the sales person can find a flexible coupling hardware kit with the required bolting.
Of course if you're using a smoke-wrench for removal, you might as well replace the rivets per original .
If you are going to do a single vehicle, buy a cheap die grinder and a good carbide burrer as well as a cut-off wheel. That and an assortment of cobalt drill bits, as well as the mentioned cutting fluid will put you in business. Or, you could do as Chris suggested, and just remove the ones on the trans crossmember which might present a dilemma at an in-opportune time.
Paul