The Ford Barn

tim54889 · 03-17-2015, 08:56 AM

What makes shocks non rebuildable? What can't be welded up and remachined back to specs? Or is it because they are so hard to get apart?
Thanks, Tim

1930artdeco · 03-17-2015, 08:58 AM

If you are referring to the original shocks they are rebuildable. You just need some specialized tools to do it.

Mike

Kurt in NJ · 03-17-2015, 09:48 AM

Labor cost, machinery investment cost

To have proper poeration all the clearances need to be good ---there are so many complex machining operations involved that it is easier to start making new parts using the same machines ----I don't see how the 70$ rebuilt shock can be returned to original tolerances on all surfaces ---not even working for burger flipping wages let alone the machinery investment, about all that price can do is bush the shaft so it is tight, but most won't have the opriginal adjustable 60/40 action

Bill Underwood · 03-17-2015, 09:52 AM

There are 13 wear surfaces each tolerance dependent on the others
Plus the are more precise than one would think

Kevin in NJ · 03-17-2015, 09:52 AM

Shocks are a tricky little device. Soo Simple, but very complex.

The shocks were made doing a bunch of operations on a jig keeping a center. It never left the jig and all reference to center was precisely maintained. So a big vane could be setup in a machined chamber with .001" or better accuracy. This included screwing a cover on and keeping tight tolerances top to bottom.

The problem today is getting the shock back to the original tolerance.

What I found was that one with just a very small amount of wear would have significantly less shock absorbing ability then the one at factory tolerance. I was quite surprised at how tight a shock needs to be to work.

Then there is the knowledge of what it means to be a good working shock. You need to look at the KRW Tester and realize how slow a fairly heavy weight is allowed to fall to be considered a pass. I have a feeling that many shocks are not even close to factory in their function. Quite frankly, until recently I would have considered a lot of shocks as being good. When I tried my close guess to the factory tool I found the shocks were not even close.

So in summation:

It is far from trivial to do a decent job rebuilding shocks.
Quite frankly, it will be very expensive to make a non-rusty but slightly worn shock good. It would be even more expensive (in labor) to get them back to factory.

You need to take a close look at the KRW Tester and realize what it means to be back to factory standard.

410merc · 03-17-2015, 10:20 AM

Sponsored Links (Register now to hide all advertisements)

I wondered about that , I got 2 pails full or more

Kevin in NJ · 03-17-2015, 11:31 AM

Some guys are doing things with the somewhat worn shocks to make them better. They are willing to pay for good cores. Even better is you can pack a lot in a USPS one rate box. So you might consider selling them.

Also, you can tell shocks that have a chance on working at flea markets. I would practice taking a few not so good shock apart if you are considering going that route.

BRENT in 10-uh-C · 03-17-2015, 11:32 AM

Answer this question below....

MikeK · 03-17-2015, 11:33 AM

Kevin, do you have a pix of the KRW device and their instructions that you could post? Just curious.

Kevin in NJ · 03-17-2015, 11:56 AM

Instructions for the KRW tools are in the Service Bulletins.

More details on the actual tool were posted here a while ago.

Brent, to get the divider out is easy. Just cut the case around it.

The devil is always in the details. I have not tried, they can clearly be a nightmare to take out nice.

Previous shock discussion Shocks

Jim Mason · 03-17-2015, 12:35 PM

Looking for 4 spicer covers with the small..no box surrounding it...keep me in mind when culling your collection

Bruce Lancaster · 03-17-2015, 01:18 PM

I think the central problem is that once the central axis wears, everything else can move far enough to contact the opposing metal surface. Once the moving vanes or pie slices start wearing, fluid can bypass more and more weakening the shock action...and once there is enough wear at center for the fluid to exit, wear accelerates and all pretense of damping disappears.
If the fluid loss happened in 1935, and the car was driven that way until 1952, there isn't going to be much left in there.
Restoring the center leaves everything else with too much clearance to pass the KRW test, and restoring the missing metal would have to be done by welding, machining, and somehow achieving the original level of tolerance while doing it.
Note the last part of the original rebuild instructions after all has been cleaned and reassembled...test the thing with the KRW weight, discard the shock if it fails!
I wonder how many passed, even a few years after they were built.

Kevin in NJ · 03-17-2015, 02:57 PM

Central axis is not the real problem, but it is all connected.

The real problem is anything more then a small clearance (on the order of .001 or so) with the vane to the body and the oil can leak around the vane. This severely reduces the shock action of the vane.

The shock wears as a unit. The shaft is the easy thing to fix, kind of. If you can not close up the vane clearance to the body then you do not get the action you need. Yes, it will have some shock effect, but in terms of factory effect, no it will not be close.

I did some experimenting on shocks and found some basics. That is what I am basing my above comments on and now that I have more details about the KRW tester I plan to do more. I need to purchase some heavier oils to use as fluids and proper characterize what I state above. Not in much rush and I am busy making speedo rebuild tools and fixing stainless radiator shells.

03-17-2015, 08:56 AM	#1
tim54889 Senior Member Join Date: Aug 2014 Posts: 120	what makes shocks non rebuildable? What makes shocks non rebuildable? What can't be welded up and remachined back to specs? Or is it because they are so hard to get apart? Thanks, Tim

03-17-2015, 08:58 AM	#2
1930artdeco Senior Member Join Date: May 2010 Location: Lynden, Wa Posts: 3,777	Re: what makes shocks non rebuildable? If you are referring to the original shocks they are rebuildable. You just need some specialized tools to do it. Mike __________________ 1930 TownSedan (Briggs) 1957 Country Sedan

03-17-2015, 09:48 AM	#3
Kurt in NJ Senior Member Join Date: May 2010 Location: on the Littlefield Posts: 6,553	Re: what makes shocks non rebuildable? Labor cost, machinery investment cost To have proper poeration all the clearances need to be good ---there are so many complex machining operations involved that it is easier to start making new parts using the same machines ----I don't see how the 70$ rebuilt shock can be returned to original tolerances on all surfaces ---not even working for burger flipping wages let alone the machinery investment, about all that price can do is bush the shaft so it is tight, but most won't have the opriginal adjustable 60/40 action

03-17-2015, 09:52 AM	#4
Bill Underwood Senior Member Join Date: May 2010 Location: Tennessee Posts: 445	Re: what makes shocks non rebuildable? There are 13 wear surfaces each tolerance dependent on the others Plus the are more precise than one would think

03-17-2015, 09:52 AM	#5
Kevin in NJ Senior Member Join Date: May 2010 Location: South East NJ Posts: 3,398	Re: what makes shocks non rebuildable? Shocks are a tricky little device. Soo Simple, but very complex. The shocks were made doing a bunch of operations on a jig keeping a center. It never left the jig and all reference to center was precisely maintained. So a big vane could be setup in a machined chamber with .001" or better accuracy. This included screwing a cover on and keeping tight tolerances top to bottom. The problem today is getting the shock back to the original tolerance. What I found was that one with just a very small amount of wear would have significantly less shock absorbing ability then the one at factory tolerance. I was quite surprised at how tight a shock needs to be to work. Then there is the knowledge of what it means to be a good working shock. You need to look at the KRW Tester and realize how slow a fairly heavy weight is allowed to fall to be considered a pass. I have a feeling that many shocks are not even close to factory in their function. Quite frankly, until recently I would have considered a lot of shocks as being good. When I tried my close guess to the factory tool I found the shocks were not even close. So in summation: It is far from trivial to do a decent job rebuilding shocks. Quite frankly, it will be very expensive to make a non-rusty but slightly worn shock good. It would be even more expensive (in labor) to get them back to factory. You need to take a close look at the KRW Tester and realize what it means to be back to factory standard.

03-17-2015, 10:20 AM	#6
410merc Junior Member Join Date: Aug 2014 Posts: 14	Re: what makes shocks non rebuildable? Sponsored Links (Register now to hide all advertisements) I wondered about that , I got 2 pails full or more

03-17-2015, 11:31 AM	#7
Kevin in NJ Senior Member Join Date: May 2010 Location: South East NJ Posts: 3,398	Re: what makes shocks non rebuildable? Some guys are doing things with the somewhat worn shocks to make them better. They are willing to pay for good cores. Even better is you can pack a lot in a USPS one rate box. So you might consider selling them. Also, you can tell shocks that have a chance on working at flea markets. I would practice taking a few not so good shock apart if you are considering going that route.

03-17-2015, 11:33 AM	#9
MikeK Senior Member Join Date: May 2010 Location: Windy City Posts: 2,919	Re: what makes shocks non rebuildable? Kevin, do you have a pix of the KRW device and their instructions that you could post? Just curious.

03-17-2015, 11:56 AM	#10
Kevin in NJ Senior Member Join Date: May 2010 Location: South East NJ Posts: 3,398	Re: what makes shocks non rebuildable? Instructions for the KRW tools are in the Service Bulletins. More details on the actual tool were posted here a while ago. Brent, to get the divider out is easy. Just cut the case around it. The devil is always in the details. I have not tried, they can clearly be a nightmare to take out nice. Previous shock discussion Shocks

03-17-2015, 12:35 PM	#11
Jim Mason Senior Member Join Date: May 2010 Posts: 948	Re: what makes shocks non rebuildable? Looking for 4 spicer covers with the small..no box surrounding it...keep me in mind when culling your collection __________________ www.jmodela.coffeecup.com Fwiw, jm.

03-17-2015, 01:18 PM	#12
Bruce Lancaster Member Emeritus Join Date: May 2010 Location: Madison, NJ Posts: 5,230	Re: what makes shocks non rebuildable? I think the central problem is that once the central axis wears, everything else can move far enough to contact the opposing metal surface. Once the moving vanes or pie slices start wearing, fluid can bypass more and more weakening the shock action...and once there is enough wear at center for the fluid to exit, wear accelerates and all pretense of damping disappears. If the fluid loss happened in 1935, and the car was driven that way until 1952, there isn't going to be much left in there. Restoring the center leaves everything else with too much clearance to pass the KRW test, and restoring the missing metal would have to be done by welding, machining, and somehow achieving the original level of tolerance while doing it. Note the last part of the original rebuild instructions after all has been cleaned and reassembled...test the thing with the KRW weight, discard the shock if it fails! I wonder how many passed, even a few years after they were built.

03-17-2015, 02:57 PM	#13
Kevin in NJ Senior Member Join Date: May 2010 Location: South East NJ Posts: 3,398	Re: what makes shocks non rebuildable? Central axis is not the real problem, but it is all connected. The real problem is anything more then a small clearance (on the order of .001 or so) with the vane to the body and the oil can leak around the vane. This severely reduces the shock action of the vane. The shock wears as a unit. The shaft is the easy thing to fix, kind of. If you can not close up the vane clearance to the body then you do not get the action you need. Yes, it will have some shock effect, but in terms of factory effect, no it will not be close. I did some experimenting on shocks and found some basics. That is what I am basing my above comments on and now that I have more details about the KRW tester I plan to do more. I need to purchase some heavier oils to use as fluids and proper characterize what I state above. Not in much rush and I am busy making speedo rebuild tools and fixing stainless radiator shells.