Valve Spring Replacement Ferguson TO 30

I have a TO 30 (with Continental Z129 engine) that has 2 broken valve springs. It runs fine but I would like to replace the 2 springs but I dont want to remove the head.

Does anyone know how to remove the valve springs from the top without first removing the head??

Never done it, but if I was to try, here"s what I"d do. Remove the rocker assembly. Make sure thet the piston is at TDC on the cylinder with the broken spring. this so so the valve can"t fall into the cylinder when you remove the retainer. Remove the valve retainer after compressing the valve spring with a special spring compressor tool. The tool is available at places that sell automotive tools. Remove the damaged spring and replace with a new spring. Compress the new spring and replace the retainer.

There's a air adapter that screws into the spark plug hole, Screw it in, apply air and it keeps the valve closed.

The other method mentioned is very "iffy". there's over .125" clearance between the valves and piston at TDC and the valve will drop that far when you remove the spring retainer...

You wont lose a valve in an 1/8"!

(quoted from post at 23:12:02 08/20/11) You wont lose a valve in an 1/8"!

Click to expand...

Like you said, you've never done it....

once the valve drops down you cannot get the keeper back on the stem to hold the spring.

Even with air if the valve guides are badly worn there will be enough leakage that it won't hold it up.

I've done a few hundred of them.

Bring each piston to TDC on the compression stroke. Then use air pressure to keep the valve closed while you replace the spring. AS been suggested you will need an adapter to thread
into the plug hole then attach your air line. I have one of the those tools for compressing the valve springs so you can install the keepers. Hal

Hi
Never tried it, but read about removing plug from
affected cylinder, turn engine by hand to have
piston at bottom. take some nylon rope about 1/4"
dia., put in through spark plug hole. Be sure
to leave tail of rope hanging out to be able to remove. Turn engine by hand to bring piston up
until feel resistance of rope against head.
This keeps the valve from dropping. After repair
reverse engine by hand to be able to remove
rope.
BE SURE TO REMOVE COIL WIRE or BATTERY PREVENT CHANCE OF STARTING

Thanks for the info.

WOW… I never expected to get so many great replys to my question abot valve spring replacement.
I have a good idea on how to proceed now, but there are two problems I could use some help with.

1.. When trying to compress the valve spring with a screw driver, I lost a couple of the tiny springs and balls that act as rotators for the valve. If I put it together without the rotators, will it still work even though the valve will not rotate??
2. I don’t know where to get the special tool to compress the valve spring with the head on. Would anyone be willing to loan me the tool if I gave a deposit to assure the safe return in a timely manner. I would pay shipping both ways. I am in Northern Illinois.
Again, thanks to everyone for the great advice and ideas.
Ron

I think you need to pull the head and have all those valve springs replaced. It will just a matter of time before another spring breaks. Hal

Replace the damaged rotator or rotators, You will be glad that you did. It is a good idea to replace all of the rotators on the exhaust valves if ANY are damaged. A "burnt valve" is much more involved and trouble to replace/fix than a valve spring. (you WILL have to remove the cylinder head to replace a "burnt valve".) I would recommend that you replace ALL of the valve springs while you are working on the engine. If two are broken, how long will the rest of them last? (Sometimes broken valve springs indicate a badly worn or damaged camshaft.) Once you replace a couple the rest will be very quick and easy. To "break loose" the keepers after applying air pressure to the cylinder just use a 1/2 inch drive socket (large enough to fit on the keepers) and "tap" it gently to "unseat" the keeper. A (low cost) spring compressor should be available from any "real" auto supply store or tool supply store. Some of the parts stores will "loan" you one if you purchase the springs from them. (It is just a piece of bent flat or formed steel with a slot and a hole in it or with two holes in it. ) It should not take longer than a few minutes to change each valve spring. Good luck in your efforts.

Friend had a home made 34 Chevy tractor with a broken valve spring.I moved the rocker arm to one side.Cleaned the end of the valve with lacquer thinner.Soldered a length of stranded wire to the end of the valve.I had a tool that hooked under the rocker shaft to compress the valve spring.You need a helper to hold the wire while you take the broken spring off.Put the new spring on.Get the keeper back on and unsolder the wire.We didnt have an air compressor.The Chevy had 2 transmissions and a model T truck rear end.It could pull a 2 bottom plow.

(quoted from post at 07:49:36 08/21/11) Hi
Never tried it, but read about removing plug from
affected cylinder, turn engine by hand to have
piston at bottom. take some nylon rope about 1/4"
dia., put in through spark plug hole. Be sure
to leave tail of rope hanging out to be able to remove. Turn engine by hand to bring piston up
until feel resistance of rope against head.
This keeps the valve from dropping. After repair
reverse engine by hand to be able to remove
rope.
BE SURE TO REMOVE COIL WIRE or BATTERY PREVENT CHANCE OF STARTING

Click to expand...

The man's right!
I've done this one many different types of engines!