New Rocker Shaft Assemblies

[77SSII]

Hey all,
does anyone have any experience w/a new rocker assembly sourced from Jeff?
I have a noisy motor that clicks constantly. The noise changes with increased rpms and is louder under load.
In a previous thread (machine shops w/IH experience in massachusetts) I went thru the valve train and I do have equal oil pressure at the pump and at both heads (50 psi). I checked con rod clearances as well as one bearing and corresponding location on the crank and all seems well.
A local grease monkey said that it sounds rocker that needs adjustment they aren't adjustable. I was told to pop the valve cover and try to get a feeler gauge between the rocker and valve. If so, that is my problem.
Any thoughts?
Thanks!

 

[Robert Kenney]

I would have to believe if you have a verified rocker arm problem it would have to be an oddity as opposed to the norm.

Have you checked lifter preload? That is kinda what the feeler gauge deal is going to tell you.

Lifter oil supply comes through the rear cam bearing and not the rocker assy.

Any possibility you have an exhaust manifold leak? Can sound a lot like a lifter tick but unlike a lifter it will make more racket under load.

Picture below is of the lifter gallery feed detail. The rear cam cover is removed here to expose the rear end of the cam. Oil to the rear cam bearing feeds through a groove in the rear cam journal to the center and out a hole in the rear of the cam. Then through the void between the cam and the cover to the 2 holes to the right and left of the cam.

 

[kyleandhisIH]

Just to answer your question about ihon rocker assemblies - I'm pretty sure the ones they offer are reconditioned and approved for use by mr. Mayben.

Now from what I understand, the IH-app 'hydraulic' lifter is designed to auto-adjust when it sees gallery oil pressure from the rear cam bearing's intermittent feed. I'm fairly sure this design relies on a carefully calculated and required preload on the lifters. Too much and you've blocked off the lifter's oil, too little and the lifter can't make up the slack. So if there is no oil pressure pumping up the lifters, I'm not sure how the lifters can be expected to stay firm enough to maintain zero free play. I would actually expect a feeler gauge to find slack in the system if the motor has been allowed to sit and some used lifters were allowed to "bleed down."

as for your noise, there's always the chance that the assembly currently installed is worn in multiple places, or perhaps one component is not in great shape. But I'd want to remove and carefully keep track of the whole valve train for measurement & inspection, before shotgunning a whole assembly.

When you went through the valve train, I'm assuming you verified the contact points and at least did a side-by-side comparison of the pushrods. Their length is the deciding factor in lifter preload, and that's if the rocker stands/rockers/valve tips have not been molested. Were the rocker shafts internally cleaned? If you have the older bushed rockers, they also need to be internally clean to deliver oil directly to the contact points.

I could be shooting the wrong gun here, because I have no idea if an out-of-spec rocker assembly will make noise in the way you have described. If you've already verified that all pushrods and rocker stands are the correct length and height respectively, and you know that none of the rockers or contact points exhibit extreme wear, then I guess I just typed all this for nothin!

Good luck figuring out the noise.

 

[77SSII]

Thanks guys!
When I was checking for oil pressure at the heads, I still had the lifters and pushrods in. When I spun the drill, the pushrods made noise and the lifters must have pumped up and pushed them up a little.
I can see no exhaust coming from anywhere. I have the tri-ys from stan's and the bolts I have use a 3/8 12-point. My 3/8 is like 5" long and I tried to tighten the "s" out of 'em.
When I removed the rocker assy. I stripped all the rockers/springs/spacer (mine is a 5-post), but I didn't remove the shaft end plugs. I sprayed brake cleaner inside. I did put tape over all the holes and used my compressor & air gun to check each hole to see if anything besides air came out. I removed the tape over 1 hole at a time and they all had air flying out of them.
My motor has had both the block and heads shaved so I have aftermarket rods. They are manley w/8.850" stamped on all of them. I took that as gospel and just rolled them like a pool cue to see if they are straight. I didn't do any side by side comparisons.
The noise seems to come from the passenger side. The rocker assy disassembled nicely on the pass. Side but the driver side, there was one rocker I couldn't get off. It would rotate a bit but I didn't want to force it off so I left it on the shaft.
I looked at both ends of the rockers and there wasn't any visible difference between any of them and they are shiny inside the concave parts where they interact w/the rods & valves.
I'll go back and remove the valve covers. I had a cover cut up so I can run the truck and check the clearance btwn the rockers & valves to reduce the bleed down time for the lifters.
Does anyone have the specs. For the id of the rockers, the od of the rocker shaft and the height of the rocker stands?
The schneider cam guy said to use risolone or rislone, I think w/each oil change to "clean out" the lifters. Could that maybe have something to do w/it. The motor has sat for about 10 years after the re-build before the truck was ready (talk about jumping the gun).

 

[Robert Kenney]

How did you come up with the new p-rod length? How much shorter are they than what you removed? Optimum lifter preload is between .025 and .050. You can have as much as .115 and not suffer any ills. I consider .025 a minumum but theoreticly anything more that .005 will work and not bang/tap loudly.

All rockers oil properly? If so your bang is lifter related and not rocker related.

Did you remove each lifter and inspect for proper function and wear? Sorry if you have already said this but I can't remember.


I frown on oil additives period so I won't agree with adding anything other that good ole dino juice to an oil pan, except for maybe comp cam break in lube or the like. I don't use it but many swear by it.

 

[71mtnscout]

The goat had horrible "valvetrain noise" when I got it. I cleaned the rocker shafts and rockers, but the main noise was the lifters not pumping up properly. I had to remove them, disassembly and sterilize them before before they quited down. If you have an older style pump oil can, you can pump up the lifters before re-installing them to check for proper operation.