Broken Valve Spring

[Barrytr6]

'69 TR6 started making a horrible noise, pulled the valve cover and noticed a broken valve spring. Is it possible to just change the one valve spring without removing the head? Thanks

 

[TR3driver]

Can be done, with some care. But if one spring broke and the others are the same age, I would sure think about replacing all of them (which can still be done without removing the head, using the same technique).

I've only done it on a TR3, but the same technique should work on a TR6. You'll need some method of holding the valve closed during the operation; I used my air compressor along with the hose from my compression gauge, mated to an air line disconnect (and the Schrader valve removed from the tip). The "rope trick" might also work : with the piston below TDC, stuff some soft cotton rope through the spark plug hole, then turn the crank so the piston compresses the rope against the valve heads.

With air pressure applied, I used a short length of 1" water pipe and a brisk rap from a BFH to loosen the keepers. Then I used a home-made spring compressor, which is a length of (approx) 2" wide by 1/4" thick steel (found at Home Depot in the building materials section as I recall) with a slot in one end to fit under a rocker pedestal nut; and a strategically located 3/4" hole to allow access to the keepers. It's only perhaps 16" long, but that is plenty of leverage to allow me to hold the spring compressed with my left hand, while picking out the keepers through the hole with needle nose pliers in my right hand.

Sorry I don't have any photos handy.

 

[Geo Hahn]

To state the obvious, if you do the rope trick keep a decent length of rope hanging out of the spark plug hole for retreiving it.

I once made a spring compressor (similar to Randall's description) out of a 1x4 (wood) just because I had it handy.

You can borrow a spring compressor from most auto parts stores but that kind is sort of a big C-clamp that requires the head to be off.

 

[RonMacPherson]

Yes you can, but I would question the veracity of the other valve springs. You can prop the valve up with either air pressure or the old rope trick. You can buy a valve spring compressor that can be used with the head on the car. K&N tool company used to sell one. Well stocked auto parts stores(the old timey ones) either have them on their tool board or can get one from the warehouse for you.

If it were my car I would replace all the associated valve springs, i.e exhaust spring broken, replace exhaust springs, intake, you get the picture... And that also can be done with the head on the car, just need to work one cylinder at a time...

 

[TR3driver]

You can buy a valve spring compressor that can be used with the head on the car. K&N tool company used to sell one.

The problem with those, at least the ones I've seen (and used), is that they don't deal well with dual (or triple as found on TR3 exhaust) springs.

 

[Barrytr6]

Thanks for the help, I will try the rope trick and replace all the springs.

 

[Brosky]

And while you're in there.............

Check the screw at the end of the rocker shaft and check the wear on all of the rockers and the shaft. If they are not worn badly, fine, but if they are, its time to do a replacement while it's all apart.

At the very least a real good soaking of the assembly for a day or so in cleaner to get all of the oil holes opened up.

Just out of curiosity, was that valve spring dry or a dull blue color by any chance? And what does the push rod look like on it's end where it rides against the rocker arm?

 

[hondo402000]

ooops