Securing steering box - tips?

[TTownEP]

My 2.5 year old son may have saved my life. At the very least, he saved me from being stranded.

I had him in the driver seat of the Bronco while I removed the weak, rusty horn from down by the steering box and washer reservoir. He happened to turn the steering wheel while I was looking down there and I saw the steering box move on the frame. I drove it to work today to grab some parts at the auto parts store, and I had one of the dudes there turn the wheel for me again so I could see what was going on. Just “a little loose on the bolts” is what we determined. “I’ll tighten it up when I get home.”

Cut to tonight: I tighten up 2/3 but find the 3rd broken off and gone!

Thankfully he wiggled the wheel when he did, I might not have caught it otherwise.

What’s the best way to secure the new hardware I’m going to go buy? Loctite and torquing them to gutentight? Crown nuts with a pin, or tie wire?

 

[luke]

Grade 8 bolts, washers, lock washers and nylock nuts. Tighten em tight.

 

[NC-Fordguy]

Lock washers will work just fine

 

[nvrstuk]

Before you tighten them up and consider the fix done, remove the other two bolts and check to see if the frame has any cracks in this area...VERY common stress area.

Also check to see if the the frame is indented where the box mounts...the frame can get bent in this area also.

SOOO, glad you caught this when you did... fix it right and you're good to go.

There are several write-ups on this site about strengthening the frame in this area and fixing this fairly common issue.

Good luck, stay safe.

 

[rustbucket]

Make sure your frame isn’t cracked. Common problem on EB’s. You can get a kit with sleeves that go through the frame.

 

[DirtDonk]

That's a 4x4x2 box, so whoever installed it might not have inserted any new reinforcments if they drilled new holes.

Normally just bolts gutentight work, but I'm pretty sure that even the factory used locking nuts. New ones are good, Locktiting them even better.

But as said, check the frame. Give it a quick tighten without all the permanent hardware and have a helper rack the wheel back and forth again, just like your son did.
This is a common test that we say (well, I say it anyway) should be done by every Bronco owner and done again whenever the mood strikes. It really showcases any trouble brewing.

Tires on the ground is the only way this works. When done right, you can find just about anything wrong with the chassis/drivetrain!

Paul

 

[DirtDonk]

Now looks to be a good time to plan your day for replacing all the body bushings too!

Paul

 

[sykanr0ng]

For a 4x4x2 box or even a factory PS box with a frame problem:

https://bcbroncos.com/shop/steering...box-frame-reinforcement-kit-for-early-bronco/

 

[TTownEP]

It looks like the P.O. welded in some new metal on the inside of the frame when he converted to the 4x4x2 box, but I’ll give it a good look when I get home with the new bolts today.


Sent from my iPhone using Tapatalk

 

[TTownEP]

https://bcbroncos.com/shop/steering...box-frame-reinforcement-kit-for-early-bronco/

If this isn’t what he used, it looks just like this.

 

[TTownEP]

Now looks to be a good time to plan your day for replacing all the body bushings too!

Paul

Yeah I know. Considering a 1” body lift at the same time, just in case I have some future mod that needs it.

 

[Timmy390]

I plated both sides of my frame, knocked out the factory incerts from inside the frame and added 1/4 inch DOM tubing. Grade 8 bolts

She's not going anywhere.

Tim

 

[sykanr0ng]

If this isn’t what he used, it looks just like this.

Then it should have the tubes reinforcing the frame so it isn't crushed.

Grade 8 bolts and nuts (or F911 bolts and nuts), Loctite or locking nuts (I'm not a fan of lock washers) and do not over-torque them.

 

[LUBr LuvR]

I think your son deserves a big hug and a scoop of ice cream! Glad he helped you discover the issue. Reminds us all to recheck and be safe.....

 

[sanndmann3]

Lock washers, lock nuts and red loctite (higher strength) ought to do it...

 

[garberz]

Use 1/2”-20 fine thread grade 8 bolts.

Mark

 

[ntsqd]

snip...... (or F911 bolts and nuts), Loctite or locking nuts (I'm not a fan of lock washers) and do not over-torque them.

^^^^ THIS.
I prefer prevailing torque lock nuts AKA "Stover nuts" or "all metal lock nuts." I see these as the "red lock-tite" of nuts where the nylocks are the "blue lock-tite" of nuts.

F911 hex bolts are both stronger and more ductile than a G8. They're my preference for any Life-Safety or 'Mission Critical' fasteners.

I throw away ALL lock washers. I usually keep star washers for electrical grounding, but those are it. Carroll Smith has it right on lock washers, read the "Engineer to Win" chapter on them.

 

[Digger556]

That bolt is showing a couple of tell tale signs of over torque. Guten-tight usually works for most folks, since their tool lengths and strengths are limited, but it is always possible to over-torque a bolt and not have it fail immediately.

Critical bolts should always be properly torqued. The goal is to not exceed the safe working load for a given fastener. To do this, you need

1) to know the proper safe torque limit for THAT FASTENER (bolt grade, diameter, pitch, and especially finish all determine max torque)
2) to use a decent torque wrench (preferably with recent calibration) Most torque wrenches are only accurate to ±10%. Good ones can achieve ±4% accuracy.
3) a clean, dry fastener. Any oil, grease, etc can severely alter the torque-to-clamp load relation. Meaning you can have the proper torque spec, but if you apply it to a lubricated bolt, you could easily exceed its max tensile strength.

One reason many people get away without a torque wrench is the generous margins put on the max working load. Generally the stated max tensile load is about 66% of the point it will fail, but that is under controlled conditions. Use an uncalibrated torque wrench with an untrained operator (aggressive "double-clicking") and a greasey bolt and you erase your margin of safety.

Although it does not appear to be true in your case, high-grade fasteners (like 12.9s), especially zinc coated ones, can suffer from what's called stress-corrosion-cracking. This occurs when you have high internal stresses combine with environmental hydrogen that lead to a time-delayed brittle fracture. Over-torquing can accelerate this issue by increasing the internal stresses and potentially giving the crack a starting point to propagate from.

 

[Skiddy]

an untrained operator (aggressive "double-clicking") and a greasey bolt and you erase your margin of safety.

.

we used to call them clicker monkeys:-X

 

[ntsqd]

I only give beam torque wrenches to our production floor. Their accuracy is good enough and you can easily tell when they're out of calibration. For those same reasons it is all that I own at home too.

Had a clicker go out of cal a long time ago and it cost the team I was working on a couple crank-shafts, a lot of rod bearings, and untold races before it was figured out.

After a bunch of research on the topic, torquing a fastener to achieve a particular pre-load on the fastener within a narrow tolerance window is at best a crap-shoot. Mostly for the reasons Digger listed. Better to measure the stretch and that's rarely convenient.