Rocker arm shaft installation?

[kshacklett]

Hello. To make a long story short...I discovered a couple rocker arm shafts apparently out of whack:



Actually I pulled out the left shaft a little beyond where I found it. The middle shaft also worked itself out quite a bit. Oil would drip from the bottom corner of the lower valve cover directly beneath where the left shaft sticks out of the housing. Don't think there's much doubt where the bulk of the oil came from.

Reinstallation? The Haynes manual says: "Install the rocker shaft, passing it through its rocker arm. Use a feeler blade inserted between the camshaft housing web and the rocker arm. Keep the blade depressed while the shaft is pushed in. When the feeler blade is felt to engage in the groove in the rocker shaft, withdraw the blade and continue to push the shaft for another 1.6 inch."

Don't know what they mean by "camshaft housing web". They don't say whether to install each shaft moving left or right. Since I can only put the left one in from right to left I assumed they all should installed that way, but what do I know? I stuck the blade on both sides of the rocker. With the blade on the left, both ends of the shaft end up in the cylinder. When I put it on the right, the shaft sticks out the left side a lot further than the others. Neither way produces a match the rest of the shafts; they all stick out maybe 3/16" on the left side (like the one on the right in the photo). It looks more correct with both shaft ends in the cylinder, so something is amiss.

Do you know the correct procedure? By the way, what we have here is a 1989 3.2 that I just pulled out of my 914.

[Eagledriver]

You want to center the shaft inside the rocker arm. Note that the bores in the cam housing are different lengths on each side of the rocker arm. It works out to having the rocker shaft just inside the end of the shorter bore. You need to loosen the pinch bolts and position the shafts, then tighten the crap out of them. (I'm sure there is a specific torque but if you use allen wrenches you can just go as tight as you can get with your fingers).

You are correct that oil will leak from the bottom when the shafts are out.

-Andy

[Flat6pac]

Looking at the rocker shafts should be part of any valve adjustment as is looking at the bottom studs if they are divilar or checking the torque on SC engines.
Bruce

[E Sully]

Haynes actually states 1/16", or 1.5mm. Insert feeler gauge next to rocker in red until you are in the shaft groove, then move shaft 1/16" to left and tighten. Rocker shafts will not extend out of housing.

[tobluforu]

When I did my last valve adjustment I could not believe that almost every shaft needed to moved, Is this normal?

[Flat6pac]

Its an inspection procedure I do whenever I do a valve adjustment thats why its important to keep them tight when you move them back.
Bruce

[E Sully]

Torque is 11 ft-lbs, 15Nm. Turn the bolt head, not the nut. RSR seals in the grooves are good prevention against oil leaks.

[john walker's workshop]

11ftlb is for when everything was new. now it's 20ftlb unless you want to chance them coming out again. you know the bores are worn from having run loose like that.

[kshacklett]

So we have the innies and the outies. I'll flip a coin. Only two things matter: Will the shafts stay put, and will the outer ones seal the oil.

The good news is that the shafts in question are upper drivers side (in my 914), which is the easiest to get to. If I have to pop the valve cover off again and install seals in the grooves, or replace a shaft it's no big deal.

The bad news is that I dropped the motor to learn something that I had already been warned about, only to realize I didn't have to drop the motor.

As long as it's out I guess I'll adjust the valves or something. Any other suggestions that don't require opening another can of worms?

[sc_rufctr]

Originally Posted by john walker's workshop

11ftlb is for when everything was new. now it's 20ftlb unless you want to chance them coming out again. you know the bores are worn from having run loose like that.

Apologies in advance but 20 foot pounds on those nuts sounds scary

[J P Stein]

There is a pic & instruction in B Anderson's book ...pg 130... on the installation of the shafts.
I've followed it (with a few new shafts standing by....and used them) and have not had any problems with shaft walk. I'm just a home builder so my experience is limited.

[Alan L]

You need two allen keys - a big one for the nut end and smaller one for bolt end. Hold the big one steady, tighten on the bolt end ONLY. I use 18 ft lb - but you cant get a torque wrench on them with engine assembled. You'll have to guess, I guess, but pretty tight. You might be able to lever on the small allen key.
Alan

[J P Stein]

Originally Posted by Alan L

You need two allen keys - a big one for the nut end and smaller one for bolt end. Hold the big one steady, tighten on the bolt end ONLY. I use 18 ft lb - but you cant get a torque wrench on them with engine assembled. You'll have to guess, I guess, but pretty tight. You might be able to lever on the small allen key.
Alan

According to Anderson (& I've found it to be true) as the torque begins to come up on the bolt, release the nut. If the nut moves, the shaft is no good. It seems to me that the sharp edge of the chamfer to the outside of the shaft is there for a reason. I figure it is there to take a minimal bite into the aluminum. Over torquing may dent the ID of the bore thus I use the factory spec. The whole set up seems a bit odd but I'm forced to assume someone did their homework figuring the out the way to make it work repeatedly.

[Alan L]

Originally Posted by J P Stein

According to Anderson (& I've found it to be true) as the torque begins to come up on the bolt, release the nut. If the nut moves, the shaft is no good. It seems to me that the sharp edge of the chamfer to the outside of the shaft is there for a reason. I figure it is there to take a minimal bite into the aluminum. Over torqueing may dent the ID of the bore thus I use the factory spec. The whole set up seems a bit odd but I'm forced to assume someone did their homework figuring the out the way to make it work repeatedly.

My book value is 13.2 ft lb. But I think the theory is the whole end is supposed to swell to hold and seal. That is why the grooves are there - to allow this movement, as far as I know. It is possible the sharp edge may bite in and lock it in place. But if the housing is already slightly oversize from previous use, I dont see much option but swelling the end a bit more til it grips.
I guess if the nut rotates during torqueing, it is not swelling enough. But I have never had them move if torqued right. I always hold the nut end steady - so it does not rotate under load = tearing the housing.
What is annoying is not being able to torque them in an assembled engine (maybe a baby torque wrench could fit?)
Alan

[J P Stein]

Originally Posted by Alan L

My book value is 13.2 ft lb. But I think the theory is the whole end is supposed to swell to hold and seal. That is why the grooves are there - to allow this movement, as far as I know. It is possible the sharp edge may bite in and lock it in place. But if the housing is already slightly oversize from previous use, I dont see much option but swelling the end a bit more til it grips.
I guess if the nut rotates during torqueing, it is not swelling enough. But I have never had them move if torqued right. I always hold the nut end steady - so it does not rotate under load = tearing the housing.
What is annoying is not being able to torque them in an assembled engine (maybe a baby torque wrench could fit?)
Alan

I do use an 1/4 inch drive, inch pound torque wrench.....with a cut down allen wrench in a socket....OK, it's kinda hokey, but fits in there. I agree, the end expands, but more so on the extreme end than close to the groove. The chamfer on the ID of the shaft is not edge broken as with normal machine shop practice. I believe there is a reason for that.....but I've been wrong before.

[Alan L]

Possibly not edge broken because it may split under tension?
Well it is nice to know, in a pinch, they can be torqued in place.
Regards
Alan

[J P Stein]

By edge broken I mean the sharp edge removed with a slight radius or very small chamfer.

[J P Stein]

By edge broken I mean the sharp edge removed with a slight radius or very small chamfer.

[T77911S]

is one indication they are tight enough is that you can turn the small allen without the big one in and the shaft will not turn?

one of mine did the same as above. i tightened the snot out of it, then put the small allen back on and tried to turn it. the allen would not turn but the shaft did not turn either, so i figured it was good to go. i have checked it several times since and all is still good.

like JW said, i thought the web may be messed up with it being lose, well, mine actually came out. so i got another shaft and bolt just in case the others were bad.

[kshacklett]

I having trouble finding torque values for my cam tower nuts. Anyone know off hand?