spring shackle bolts

[avantey]

I have a problem with wear of the shackle bolts for a 1916 Hupp I am doing. They are drilled, cross drilled and fitted with grease cups. The wear is at the point of contact inside the bushing. All I can think to do is sprayweld to build them back up and turn them to size. Not sure what this would to the drill and cross drill for grease, probably plug them.

Any other options out there for this problem? I would love to hear them! A couple of months ago I got GREAT feedback on whether to powder coat the frame for this car I am hoping for your insight and help again...

thnaks- Bill

[56Roadmaster]

You should use caution in applying spray welding (or any welding)to a metal of unknwown composition, while you may end up with something that "looks good" you may embrittle the material- granted they are probably some type or carbon steel-which may cost you a car or your life. Those pins are probably "soaked" with grease (on a microscopic level) grease being a petroleum product which is a hydro-carbon compund at weld temperatures hydrogen atoms will enter the weld zone and can cause lack of fusion and cracking at a much later date. Additionally without knowing what the compsition is you can change the microscopic structure (which can be corrected by heat treatment) which may cause failure as well. Best to talk to an experiecned weld shop or machine shop and pick a suitable replacement steel to machine new ones from. You really don't know the loading the pins take with out dynamic analysis. however someone very familiar with design for similar items would be a good start. I doubt Hupp engineers of the day just guessed.

[avantey]

Scott-thanks! I had not thought of the metallurgy possibilities from spray welding. I have considered machining new ones but I am not sure of how the grease cups attach. The current ones have a straight knurl that runs right up to the back of the grease cup. I have other bare bolts that have threads turned on both ends, drilled and cross drilled. This makes me think the cups are threaded onto the bolt which would make sense with the machining abilities of the era. However the shackle bolts in question are for the front mounts of the rear springs and the cup goes all the way onto this knurl like they are pressed on. I have to degrease them better and inspect them more closely. Could the cup be silver soldered to the shaft? Or just pressed on?

thanks for the help- Bill

[Mark Shaw]

I have some extra shackle bolts. What are the dimensions you need?

Mark Shaw

[avantey]

Mark- thanks for the offer! These all have grease cups on the end and most have a straight knurl (1/4") just behind the cup. The ones I need most are for the front of the rear springs to the frame. They are a 3/4" x 3 7/8 from the back of the cup. It has about 3/4" of fine thread for the nut.

The others are 1/2 x 4. I have some that appear to be spares. they have threads at both ends like the cups thread on. Could this be right? The large ones above appear to be a pressed on part or turned part of the bolt.

Either way thank you for the reponse and sorry about the delay in getting back to you. I do check this forum that often but I should!!

thanks- Bill

[Ivan Saxton]

Meltal spray is fine for rebuilding shackle pins. The material that should be used is Metco Spraysteel 80 which you have to grind, or Spraysteel LS which is a very useful material that you can machine carefully with tungsten carbide tools. You always should seal coatings with a wax or phenolic sealer. Coatings often last much better than the original item, possibly because the slight porosity holds lubricant on the surface.

If you have a lathe and want to make new ones you use a good quality alloy case hardening steel like EN36A. You can case harden these yourself by using the right material to soak the machined items red hot. If you are careful with machining finish and size you can use them after just taping them in the lathe with abrasive, but I prefer to make them oversize and grind.