Hope this thread will stay with this forum. I think I've read most of the radius arm bushing replacement replies, and still have a couple of questions. My approach will be to remove the radius arm brackets. I know the driver's side bracket has at least one rivet that I will grind and replace. My truck is a '76, F350. Will the passenger side bracket be bolted on or riveted? Discussions I've read are not all in agreement on this. I would verify myself, but it's just too cold right now to crawl under the truck. Next question is the size of the grade 8 bolts I will need. I believe they should be 1 1/2 inch long, but should I get 1/2 or 7/16? Are they all the same size, and how many will I need. Final question: Is the rear radius arm retaining nut 1 1/8, or 1 3/8?

Thanks

 

vettman wrote:
> My approach will be to remove the radius arm brackets.

BTDT both ways and for sure the best way to go is to remove 'em IMO. :)

>I know the driver's side bracket has at least one rivet that I will grind and
> replace.

Four rivets in each bracket and it ain't coming off without all of the rivets
having one head ground-off or cold-chiseled-off and then punched out.

Each one was "upset" to fill all the voids.

>My truck is a '76, F350.

I believe they are the same.
My pictures are from a '75 F150.

> Will the passenger side bracket be bolted on or riveted?

Originally it was riveted, betcha a dollar. ;)
If it came from the factory bolted then the factories alignment guy had to
un-rivet it and move it. BTDT too. ;) That's why my driver's side is bolted.

> I would verify myself, but it's just too cold right now to crawl under the
> truck.

70.7*F ;)

>Next question is the size of the grade 8 bolts I will need.

I used 7/16". YMMV

>I believe they should be 1 1/2 inch long, but should I get 1/2 or 7/16?

Mine are 1+1/4" x 7/16" grade-8 "long" flywheel bolts I picked up at
wrecking yards (they give stuff like that away;).

>Are they all the same size, and how many will I need.

All four of mine are the same size.

>Final question:
>Is the rear radius arm retaining nut 1 1/8, or 1 3/8?

Actually it's a 3/4-10. ;)
But yeah, the "best" socket to use is a deep well 1+1/8".

http://www.panix.com/~alvinj/file12/radiusarm.jpg
The rivets are 3/8" and not any stronger than a grade-2 bolt in my estimation
and along with that will stretch quite a bit before breaking.

The rivet there (in between my flywheel bolts) is the same type and diameter
rivet that was in the radius arm bracket. ~3/8" but has been upset to fill the
hole so there's no movement without stretching the rivets.

I measured the crap;) out of my alignment and finally decided to move that
radius arm bracket forward ~5/16". You can see where it's up against the
body support bracket and I ground off a little bit of the corner too.

My pickup's "square" as anything! :)
Is yours? :/

http://www.panix.com/~alvinj/file12/radiusarm1.jpg
Just another angle showing the lower rear bolt head.

http://www.panix.com/~alvinj/file12/radiusarm2.jpg
You can see they I used 7/16-20 right hand thread wheel lug nuts turned
upside down. They are kinda like extra heavy duty flanged nuts, see? ;)

On the passenger side mine still has the original rivets and my plan is to
remove the rivets and replace them with flywheel bolts and lug nuts too.

In my case, on the passenger side, I don't want that sucker to move any. :)
So I will do each rivet one at a time, reaming the hole using a drill bit and rat
tail file so the bolts are a good snug fit.

In your case, I'd suggest doing it the same (if the squareness is the way you
want it) but when you get the last bolt fit in, only then remove the other bolts
you installed.

No use getting in a hurry and making your pickup drive funny. ;)

Alvin in AZ "takes me longer when I get in a hurry"
ps- I asked my metallurgy teacher about the grade-5 bolts versus grade-8
bolts "automotive newsgroup controversy" and he just laughed. :) What it
took to stretched out and ruin a grade-5... chances are, in the same place...
would have left the grade-8 bolt un-phased.
{edit: do yourself a favor and don't add any washers and especially them
$%&#$%# split-ring "lock" washers! Ok? :)}

 

Thanks for the detailed response, Alvin. I was planning to remove the rivets one at a time, ream and bolt as you suggest. I have a torch, but think I'll just grind the heads off the rivets and punch out--what do you think? I'm the original owner of this truck and it only has 72K miles; always garaged, and never been in an accident. Based on tire wear, steering/tracking, etc., I'm pretty sure the truck is "square", so will be keeping both brackets in their original locations. Also, you've used some terminology I'm not familiar with: BTDT?? YMMV?? Also, what is a 3/4-10 nut, and how/why does it need a
1 1/8-in. socket. I plan to use some loc-tite on the bracket bolts instead of split washers.

 

vettman wrote:
> BTDT??

Been There Done That

> YMMV??

Your Mileage May Vary

> what is a 3/4-10 nut...

The bolt threads are 10 per inch and the bolt's outside diameter is 3/4 inch.
3/4-10 :)
The nut has that thread too. ;)

> why does it need a 1 1/8-in. socket.

A guy could use an open end wrench but it's "old school". :/
http://www.panix.com/~alvinj/file12/toolbox.jpg
That's why I like to use the old "plow wrench" pictured there. LOL :)

The small end is 1+1/8" and fits the radius arm bolt also the nut inside the
coil spring and the large end is 1+5/16" and fits the pitman arm nut. :)

> I plan to use some loc-tite on the bracket bolts instead of split washers.

IMO (in my opinion;) even anti-seize is better than split-ring "lock" washers
and/or soft-assed grade 2 washers being added for no good reason.

A torch will burn up more than just the rivet head so yeah, I like the little
hand grinder idea or a cold chisel even.

-----------------------------

My old "signal bonding hammer" is pictured there too, it was old and had a
broken handle when I found it in the "Mesa motorcar tool house". I put a
handle in it in Sept of '73 while waiting on trains and used a piece of broken
hickory "spike maul handle" and the "track walker" I was working with that
day said "that handle should last you a life time :)" And so it has. :)

That sucker's hit a cold chisel as hard as I could a -lot- of times.
Even my hand a few times. LOL :)

It has "Fairmount" stamped into the side of the head, always wondered if it
had anything to do with the motorcar company, if it came with a motorcar.

Alvin in AZ
Ronaldo "Chicken" Badilla

 

Why remove the brackets????? Chances are the radius rod studs are severly rusted beyond being safe. Remove the nut with a big wrench or use a torch. Burn the bolt off both in front and rear of the rubbers. The heat will disolve the rubbers to the point they can be easily removed. Drive out the front pin. Now that the radius rods are scrap you need to fix em. Simple. Cut off the stud that sticks out and drill out the bolt. The origanals drill easily. Stuff the whole rod in a vise and take your time drilling. Stuff in a grade 8 bolt and weld in place. Now you have new radfius rod studs and bushings.

 

Not sure I completelyunderstand Zoomeroo's approach; regardless, since I have hardly any rust on/under my truck (thanks to Zeibart, being garaged, low miles, no salted road driving, etc.), I'll be proceding with bracket removal as my approach to this job. Thanks for the "enlightment" re. your abbreviations, Alvin. I'll use a 4.5-inch grinder to remove the rivet heads. I have 1 1/8 deep impact socket in my tool box, so after some "soaking" I should be able to get the nut off. Do you think it's okay to re-use the castelated nut? Love your "old/used" tools. I have some, too, including a small sledge that has been re-handled a few times over it's life.

 

just do what alvin said and don't over think the job,the idea of taking one rivet at a time and then drilling the hole 7/16 ths and then onward with the rest.get a torch or an impact gun and take your nut of and pull out your old bushing and put it back together.I used washers on mine,7/16 x1 1/4 bolt with non-nylon lock nut and a flat washer on each side.my truck had one bolt in each bracket,without a washer.good practice is to use new bolts,don't reuse old bolts in your suspension to save $10,always a bad idea.

 

Because!!!!! ;) LOL :)

IMO only now...
I replaced the NOS bushings (I'd put in) with graphite/black poly-urethane
EnergySuspensionParts.com bushings and one side was un-boltable and the
other side wasn't... I saw the difference it made in how it easy it was to do
on the side with the removable radius arm bracket and difficult to do that
same quality of work on the other. YMMV

Back there in the "rust belt" that's prob'ly a good method. ;)
I don't know nuthin' about that. :/

Can you drill out and weld a new bolt into "the forged type" radius arm?
http://www.panix.com/~alvinj/file12/radiusarms.jpg

Don't forget, it's not an ordinary bolt it's a "shoulder bolt"...
http://www.panix.com/~alvinj/file12/radiusarms1.jpg

To return it to stock dimensions, a guy could use a 3/4" bolt and slip a piece
of 4140 or 4340 tubing over the bolt. The "stamped out sheet metal" radius
arm's shoulder is 3+1/8" long on that one and 3" long on the forged one.

I spark tested those two bolts and my guess is they aren't 4140 or 4340
either one and more like simple medium carbon steel, like 1040 to 1060 and
the heat treatment or work hardening I don't know. Better spark testing
requires a darker time of the day.

Also the diameter I don't know but guess it's about 15/16" since those two
came from "back east". ;)

When welding medium carbon steel parts pre-heat and post-heat are both
needed or just one of them? {shrug}

I'd do both. ;)

Alvin in AZ (out west)

 

Truer words were never said. :)

Alvin in AZ
ps- Do what's right, not what I say or do! :)

 

Alvin... Thanks for all your advice on this subject. I ordered my 7/16 x 1-1/2 inch bolts, lock nuts, and flat washers today--everything is grade 8. NAPA has the OEM-style bushings at $15.99 per side. Looks like I'll have about $30 total in parts to do the job. Now as for my labor, well I guess it will be free. LOL. Won't start until it warms up here in Northern VA.

 

i know this is an old thread but was doing some searching for my issues and this is the closest i could find.

i have a 1986 f350 2wd and the bushings are shot on the front radius arms. my problem is nothing is going to get the nuts off where the bushings are. i have been told to drill out, chisel or grind off the rivets as this thread suggests. but that just frees up the radius are at the front. i am thinking i also need to cut the arm and install new ones along with bushings and grade 8 bolts and nuts to reattach to the axle.
any advice?
thanks,
Barry

 

"good threads never die! :)" -Alvin

Just get some new radius arms and nuts and hardware and get after it! :)

I'd suggest measuring the squareness of the frame and stuff before
tearing into it so you make corrections while you're at if needed. BTDT

It won't hurt to measure it, especially if it's already -perfect-, right? ;)

I remove one rivet and rattail file that hole to match the bolt and bolt it
down and go to another until I feel like the radius arm bracket's going
to go back -exactly- where I want it after complete removal. Tinkering
fools like me do stuff that way a lot. ;) YMMV

Fill out your stuff.
Where you at? :)
I'm guessing somewhere in the "rust belt"? :/

Removed the rivets from a '91 Bronco since this thread was started...
http://www.panix.com/~alvinj/file12/radiusarmB.jpg

-------------------------------

For the rivets that are hard to get to, something that turned out useful
for me was to cut an X down into the head of the rivet with a Dremel or
cut off wheel. Those cuts (even just 1 helps) opens up a place for the
piece you're cutting off to go and so giving space for the cold chisel, see?

Learned that trick here on FTE I believe. :)

Before using that trick one thing I figured out was to not peck at the rivet
with a regular hammer and cold chisel, use the biggest hammer you can.

Any good hammer mechanic knows that concept. ;)
Use it.

A 10 pound sledge single handed under the truck was too much for me
now that I've got old and worthless. An 8 pound on the other hand was
perfect! :) It'd cut those dangged rivet heads off like it meant business! :)

The rivets would work harden with those "light taps" like from a weak air
hammer or little 40oz hammer. :/ Next thing you know the rivet is as hard
as the chisel and dulling the chisel even denting the chisel! BTDT and it
sucks because once that chisel edge starts dulling, cutting stops!

Spark-testing the rivets didn't show much carbon, so not all the way sure
what's going on with that work hardening business. :/

Like a new pocket knife, the factory sharpens a cold chisel at a -way-too-
"steep" of an angle. So lay-the-edge-angle-back on the cold chisel. :)
That'll help it cut and not want to work harden the rivet or whatever else
you're cutting.

The angle you can get away with is dependent on you, the chisel and
what you're cutting. So there's no set angle, you have to find it for
yourself, you -can- do that right? ;)

Also you'll notice right away some rivets punch out easy and some pretty
much have to be punched out from the other side, so you kinda have to
start all over cutting off the other head. I believe it has to do with the
direction the parts were punched and the fact the holes aren't straight
holes but instead tapered holes. All of 'em.

Alvin in AZ