Help! Need to replace broken valve spring

[chrismlee22]

Anybody know how to replace a broken valve spring? Can I just pick up a new spring at the parts store? I have a manual that says I need to have it checked.....installed height minus valve height or something like that. Or can I just put it in there and go?

ANY help is appreciated.

1978 Bronco 400M

 

[Billz4x4z]

Are you running a stock cam??If so you can get by with just changing the spring out.Have you ever done it before?

 

[79fever]

If your budget allows, I'd replace them all. I played the game of replacing one here & one there....but, you have to live within your budget.. If the cam isn't stock, stay with the cam manufacturer's recommendation for springs. Good luck.

 

[RTM]

The shimming may not be needed. if you have a high mileage motor and you need to replace a stock spring then I would just replace the stock spring and go from there.

In order to shim you just measure the gap between the spring seat and the bottom of the retainer. That will give you the hieght. Then you should have the spring checked to see if it has the correct load at the height or spring pressure.

To replace the spring you need to fill the cylinder with air. This has to be done or the valve will fall down into the cylinder. It's also best to bring the piston up to or as close as yopu can get to top dead center. This way if the valve falls down you may still be able to grab the top of the valve. They make a tool that will remove the spring with the head on the motor. It bolts down to the rocker arm mount and you just pry the spring down and remove the keepers and so on. I made a tool to this on a chevy motor once out of a pry bar.

 

[79bigbronco]

The shimming may not be needed.