Cylinder #1 rocker shaft removal issue

[Packy]

Im trying to replace my springs on all valves. I am removing the rocker arm on the #1 intake valve of a '79 3.0 SC. The shaft only slides out one way and the problem is it slides right into the chain box and there isn't enough room to slide it completely out. Do I have to remove the chain box or am I missing something?

[Flat6pac]

Push it the other way. If there isn't room because of #2 rocker shaft, loosen and move #2 out of the way...
Unless you have a broken spring why not save the work for a valve job, a shop has the tools to test spring pressure when assembling the heads.
Bruce

[Packy]

I have a broken valve retainer so I'm changing the springs, retainers, seats and keepers on all valves as a precautionary measure. This rocker shaft wont slide all the way through to the #2 shaft. Do I need to heat up the cam housing to slide it through? I'll measure with some calipers but these shafts shouldn't be tapered right?

[Flat6pac]

You should have some excess from the #2 shaft making it hard to drive the #1 shaft to the left all the way as the proper location for the shaft is at or just above level on the narrow boss that holds the shaft.
Loosen the #2 and move it to the left. That will give you enough room to drive #1 shaft to the left. Because of location and access you might drive off the split in the shaft to get enough leverage.
There is no taper.
Bruce

[304065]

make absolutely certain the cam is out of the way
I assume you have both cones and the pinch bolt out of there.
Yes it pushes out to the inside. When you reassemble you should be sure to put the bolt head to the inside like the factory did. Unlike in the rest of the universe where the bolt head is held and the nut turned, for the rocker shafts you hold the nut still with an M8 Allen wrench and turn the bolt head on the inboard side with a cut-down M5. See here for prior art:

Question for the Pros or Semi-Pros: How do YOU torque rocker shafts?

Anyway back to your problem-- I would heat the aluminum and cool the steel shaft with some computer duster held upside down, don't give yourself frostbite. Then push the shaft through to the inboard side. You really want to avoid scoring the bore of the cam tower-- and when you put it back together use the RSR seals for insurance.

[Lapkritis]

Originally Posted by Packy

Im trying to replace my springs on all valves. I am removing the rocker arm on the #1 intake valve of a '79 3.0 SC. The shaft only slides out one way and the problem is it slides right into the chain box and there isn't enough room to slide it completely out. Do I have to remove the chain box or am I missing something?

I would use a long screw driver for a fulcrum down past the rocker to the head where the bolt is visible beneath. Use a second screw driver as a lever against the fulcrum to gently drive the rocker to the left. Add a deep socket seated against the rocker once you're out of travel. Steady even pressure with appropriately sized levers, no impacts.

[Walt Fricke]

As Lapkritis notes, you have to be creative in pushing this shaft out due to limited access. Same deal with the diagonally opposite one on the other side. #1 intake translates to #6 intake if my mental picture is correct, but you'll see. The oil cooler causes the same issue.

I keep shoving in more sockets. Keep a magnet on a stick handy (flexible ones by far the best here) to fish out the expedients you slip in.

And be careful about prying much using the chain box. It is not the strongest part of the motor.

I'd hold off on heating/cooling unless and until you get the shaft sticking out partly into the interior space you have to use. Those would be expedients only needed if it gets stuck, so to speak, and you can't push it out. The idea of computer evaporating spray is interesting, though I'm not sure it would do much good, what with warmed aluminum and only a small stub of the shaft you could cool in situ. This isn't a shrink fit gear on a shaft.

Good luck with the spring changing. I found it hard to deal with an exhaust spring at a track, though a helpful mechanic paddocked next to me whipped the new one in. Much more room for the intakes, though.

[DSPTurtle]

Tapity tap. L shaped Allen and a little tappy tap with a hammer will let you make some progress.

[JFairman]

I've used different L shaped allen wrenches as little pry bars with different size and length 3/8" sockets under the 90 degree bend of the allen wrench braced against the chain case housing to lever push the rocker shaft out in similar situations as yours.

It's not likely it's stuck in there hard enough to hurt the chain case while doing that slowly and carefully in steps.

New rocker shafts and polished used rocker shafts slide in or out easily. Craig Garrett who posts as "Cgarr" here does a nice job polishing the shafts and resurfacing and rebushing the rocker arms.

Good luck with it.

[Packy]

Okay, thanks guys. I got it out by cutting an allan wrench short, using a little focussed heat and some clever hammering.

Next question:
I had two rocker shafts with the bushing/cone stuck in. Is it okay to buy two new rocker shafts or is this a no-no. I know with hardened parts like the rocker arm the wear patterns need to match up. Can I buy another rocker shaft without replacing the rocker?

Question two:
Cylinder 6 intake rocker had some wavy wear and a small chunk taken out of the surface that rides on the cam. The cam looks fine and has no abnormal wear. Can I replace this rocker without big consequences? I am not taking the cam out. I feel like replacing this rocker is better than not replacing it even with potential for abnormal wear.

Any thoughts?

[304065]

I don't see an issue with changing the rocker shaft. But see if you can get the cone out, did it rust in place? One thing you should definitely do is use new pinch bolts and nuts at any place you feel compromised.

no prob to replace individual rocker bushing as long as the cam OK. I would be very suspicious that it was ok, however.

[Walt Fricke]

You can replace individual rockers. No problem there. The "chunk" out of a rocker surface is often the result of wearing through the surface hardening somehow, so replacing one which shows this seems like a good idea. Though it is a matter of opinion as to how big a pit it needs to be before replacement becomes more mandatory.

While it is often recommended that you keep track of the rockers so they go back in so they ride on the same cam lobe they are used to riding on (in case the surfaces are not absolutely parallel to the cam axis), individual rockers are frequently replaced, with the rest reused.

Same with the shafts if you need to replace any. These are not parts which wear in as sets or pairs or whatnot.

Ditto on trying to free the stuck cones. Maybe a little rust, and if you can get them off, a little cleaning and polishing and maybe use just a little lubricant (I'll have to remember to try that next time I reassemble a top end - just might give a hair more expansion) and all should go back to working.

[Walt Fricke]

Oh - if you want to rebush rockers, Craig does that quite reasonably, and uses an interesting oil impregnated bushing. He'll redo the wear surface, too, and polish it. And if any rockers aren't up to snuff, he'll tell you need better ones, and not spend time refurbishing.