Lower wishbone, fulcrum shaft removal

[Apprentice1975]

hi there e type people,
my first technical post.
A simple question I hope...

Is the lower wishbone fulcrum shaft an interference fit where it has been pressed into the wishbone when first assembled?
I've read in a previous thread that force and heat is needed to separate the shaft from the wishbone because they get seized in over time.

I'm also trying to understand how the lower wishbone reacts
with the torsional force or resistance created by the torsion bar.
Does the wishbone need to rotate freely on the fulcrum shaft?

My plan is to get the wishbones plated or powder coated after i've separated and cleaned them up..

please see a picture.
thank you

[abowie]

Is the lower wishbone fulcrum shaft an interference fit where it has been pressed into the wishbone when first assembled?

No they just rust together.

Heat and a hammer or a press will separate them, although sometimes you may damage the fulcrum shaft in doing it.

Consider the fulcrum shaft, which can be bought new, to be sacrificial if necessary, but protect the two castings as they can't.

When assembled on the car the shaft doesn't move in the castings.

Zinc plating is the way to go, unless you can get Cad plating done in Perth. We have one place in Adelaide that can do it.

[Apprentice1975]

thanks Andrew,
will the fulcrum shaft fit in the wishbone after it's been plated?
thanks

[mgcjag]

Hi Colin...depends how thick the plating is....but yes they usually do.....Steve

[angelw]

Colin Wrote:

will the fulcrum shaft fit in the wishbone after it's been plated?

Yes.

Regards,

Bill

[Apprentice1975]

thanks Bill

[abowie]

thanks Andrew,
will the fulcrum shaft fit in the wishbone after it's been plated?
thanks

Yes. We always plate them on restos.

The new ones come zinc plated.

[RTaillieu]

If you buy new fulcrum shafts run a thread chaser over both ends. I bought new shafts from SNG and the nuts wouldn't screw on to the new shafts because of the plating. After using the thread chaser on them the nuts spin on nicely.

Rick

[Gfhug]

If you don't have a thread chaser a castellated nut will often do the job, run it down the threads with the castle section first.

Geoff

[Series1 Stu]

Good tip, there.

Or, you could file a groove in a sacrificial standard nut to give the same effect.

Keep reversing the nut half a turn after every full turn to break any build up of dirt and excess plating.

Regards

[Apprentice1975]

I finally managed to fully pull apart the first lower wishbone .

Method:
1. carefully cut through the seized bolt head that connects the 2 legs of the wishbone using an 4" angle grinder cutting disk. Pressed bolt out.
2. Tried to press out lower fulcrum shaft through both wishbone legs using my cheapo 6t press, no joy, solid....
3. Applied heat to the two legs where fulcrum shaft passes through ,, using LPG / flame flame , blow torch.
There was just enough heat to get some movement. No need for acetylene gas...
4. Pressed shaft again while hot.
A bit of messing around with my bottle jack style hydraulic press to get enough stroke for the shaft to pass.

I used welding gloves and face shield for protection.

1 down 1 to go and fingers crossed.!
thanks to all who contributed .
see some pics