Helpful Tips: Removing Perch Bolts From The Front Axle, Model A
 

In about two months I'll be completely rebuilding the brake system and the front suspension. I've been collecting all the parts it takes, and I can see that there's an end in sight.

The procedures are straight forward enough, but there is one process that concerns me. Its not talked about very much, and I've been able to pick up only a couple tips from previous posts.

As the title says, it's the process of removing the perch bolts from the front axle. They've been living in there for 90 years, and I think they like it in there. I want to evict them, and I'll kill them to do it.

Two things I've read:
1. Don't apply heat to the axle on account of axle tempering issues.
2. Previous accounts record that just under 20 tons of force was required to press the bolts out (I'll bet this value can vary a lot).

I'd sure hate to get stonewalled when I get to this step, so I'm doing my research now. I was hoping to just pick up another axle and do the work in advance, but finding a decent non-heated axle from a reputable source has been elusive.

I will say that I have been periodically applying liberal amounts of Kroil and PB Blaster (alternately) for several months now, and more frequently in recent weeks. I hesitate to share this lest this thread turn into a Master Chef Show of cooking oils.

Barn-ers, could you please share you experience and "how-to" in removing the perch bolts from the axle?
Were you successful?
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Re: Helpful Tips: Removing Perch Bolts From The Front Axle, Model A
 

I have had this problem and could not remove the perch . I took it to a machine shop and well over 20 tons were pressed on it but no go . Heat was applied but not to cherry red but still no go . In the end I repaired the perch, the shackle had worn clear through the bushing so I cut out the very thin part and fitted a new bushing .I then MIG welded the bushing in place . It was a neat repair and not very visible and would never ever fail in my lifetime . You would have to do a monster mileage to wear through the bushing again if kept greased as recommended .

John in wind and rain Suffolk County England .

Re: Helpful Tips: Removing Perch Bolts From The Front Axle, Model A
 

You are better off not removing them and instead welding the hole back to the original size. Most people do that and do not have any issues. By the time you get them out, you probably will have screwed the axle up.

Re: Helpful Tips: Removing Perch Bolts From The Front Axle, Model A
 

My first axle that I disassembled the car was only 50 years old. I didn't have a press nor a torch, I was using liquid wrench at that time. Wanting to save the perch I blocked the axle upside down on the concrete floor, with a 2inch round brass punch and a ( Big hammer) I beat on the threaded end of the perch. Turning the axle over I then used a long bar and tried turning the perch, one way and then the other way. At first it would only move a hair, turned the axle over and again using the brass punch and a big hammer beat on the threaded end ( make sure you install a nut or two on the threads). Repeating until I could move the perch with now a steel punch. In the end I was able to reuse the perch.

The second two axles the spring perches were not saved, they were junk , so I used a torch on the perches and got them red hot and again liquid wrench ( it will burn when it gets hot) I beat the perches out, I may have cut the threads flush with the axle.

Side note : when using heat you heat a bolt, stud , perch not the mass part. Think of removing studs from an engine block using heat, heat the stud not the block. Heating a stud bolt perch the part expands and then when it cools is what breaks the parts loose.

Re: Helpful Tips: Removing Perch Bolts From The Front Axle, Model A
 

If ever one finds unspoiled perch bolts already removed it's certainly worth a reasonable price as someone has already labored to get them out, I found (3) pair of n.o.s. wired together for a 32 project several years ago, as stated the big project was getting the old ones out....

Re: Helpful Tips: Removing Perch Bolts From The Front Axle, Model A
 

When people say you destroy the axle when you heat it I have to
think of the thousands of dropped axles out there.

Re: Helpful Tips: Removing Perch Bolts From The Front Axle, Model A
 

Then there's:

Re: Helpful Tips: Removing Perch Bolts From The Front Axle, Model A
 

Hole? So far, all the holes are fine. Its the perch bolts that are the issue.

The biggest problem is that the perches are not fully bolted down onto the wishbone forks. There is a slight movement between the wishbone forks and the axle. It's been like that for a very long time.

To fix that I would need to get the perch bolts moving inside the axle...and if I can do that, I'd rather just replace them.

Re: Helpful Tips: Removing Perch Bolts From The Front Axle, Model A
 

We recently removed the perch bolts from my grandson's 1930 Tudor. We had to heat the perch nut until it glowed, we quenched it with a wet rag and were then able to remove it with an impact wrench. Once the nut was off the perch was easily removed.

The axle was bent into a gentle smile. We took the axle to a shop that has a 200 ton press and bent it back into shape. The shop has a set of pins we inserted into the four holes in the axle and then checked the straightness with a long straight piece of steel.

Tom Endy

Re: Helpful Tips: Removing Perch Bolts From The Front Axle, Model A
 

So far in this thread, no one has said anything about 'destroying' axles by heating them.

What has been said is that when you apply heat, there are tempering issues. I'm not a metallurgist, but its well known that heating to high temperatures affects the metal structure/grain in some way.

Some temperatures will anneal the metal, and some will temper the metal, but usually when high heat is applied in a somewhat uncontrolled manner in a localized area only, it will set up internal stresses. The results of those localized stresses? Anything from 'nothing', to 'catastrophic failure' at some point down the road (sorry for the pun).

So, you cant just hold up a home-brewed heated sample and declare that it works, and you can't do that after just a few hundred miles either. Also, without a statistical sampling size of home-brewed heated samples, you really cant draw much of a conclusion at all...and because there are so many variables, the sample size would need to be enormous.

If a drop axle was truly desired, one would hope that such a project would be well thought out and engineered. If it was me, I would heat-form the axle, then anneal the entire axle in an oven, and then temper it per Ford specs. But before I did any of that, I would consult with a metallurgist and/or engineer.

"...thousands of dropped axles out there". Most were probably made professionally.

Welcome to my anal retentive life :rolleyes:
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Re: Helpful Tips: Removing Perch Bolts From The Front Axle, Model A
 

See post #10.
The important thing is, not so much the amount of metal manipulation, as is the conditions under which it was done.

Re: Helpful Tips: Removing Perch Bolts From The Front Axle, Model A
 

Hey Tom-

Did you heat the nuts because they were stuck, or to soak heat into the perches because they were stuck? Or both maybe?

Also, you quenched it with a wet rag...why did you choose this method?
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Re: Helpful Tips: Removing Perch Bolts From The Front Axle, Model A
 

Has anyone actually seen a Model A axle failure due to heat being applied to remove perch bolts.
What was the failure, and what were the conditions that caused it.

Re: Helpful Tips: Removing Perch Bolts From The Front Axle, Model A
 

There is no harm heating an axle to drop it or straighten it. It is a forging and was made by heating. Let it air cool only.

John

Re: Helpful Tips: Removing Perch Bolts From The Front Axle, Model A
 

The way I remove the bolts is to use an air hammer on the bottom of the perch.
Grind a bit or buy a hammer bit like a flat punch. With the nut to center it,hit it with the air hammer. Iusually have to heat the axle also,but it works cold sometimes

I think this works better than a pRess.Sometimes the perch comes out unhurt.

John

Re: Helpful Tips: Removing Perch Bolts From The Front Axle, Model A
 

I took two AA axles apart recently. Same only bigger. After liberal baptisms with penetrant, I loosened nuts and between pounding on nut with a big brass hammer and applying twisting force with a BIG wrench I was eventually able to get them out. I had one nut I had to apply heat to but didn’t have to heat axles.

Re: Helpful Tips: Removing Perch Bolts From The Front Axle, Model A
 

in one of the Service Letters the Branch stated that it became aware how dealers were using heat to straighten bent axles and disapproved of the process. But nothing was stated in terms of specific ramifications resulting from that practice.

If a Model "A" owner got in an accident, I would think the status of the front axle would be the least of his worries.

Re: Helpful Tips: Removing Perch Bolts From The Front Axle, Model A
 

You can heat anything, ......A little! 4-500 degrees ought not disturb the temper. Henry did say Bend Cold! A nut and bolt loosener that's better is 1 part acetone to one part ATF. This has been proven so many times I'm surprised no one sells it commercially.
Terry

Re: Helpful Tips: Removing Perch Bolts From The Front Axle, Model A
 

I welded two brackets on the end of a six foot pipe with 5/8" holes in them so they straddle the spring eye. then run a bolt through the spring eye and brackets and tighten. Now you have enough leverage to rotate the eyebolt back and forth with penetrating oil and they will come out.
I have taken a lot of them out and have never heated an axle.
Bill

Re: Helpful Tips: Removing Perch Bolts From The Front Axle, Model A
 

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