One of my rocker studs has had a subtantial groove worn along one side resulting in the rocker arm twisting and bending the pushrod.

How do you remove and replace one of these studs? The Haynes manual insinuates that this can be done with the head installed in the car.

Any advice would be appreciated.

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83 Berlinetta - LG4, Mr Gasket Shorty Headers, Custom Y pipe, 3" pipework, 3" Vortech Muffler, Performer Intake, Open Element, QJet mods. Best 1/4 Et 15.11 @ 90.4 mph, 2.097 60ft.

 

Nem,

Remove the rocker cover, offending rocker arm, and push rod. Stack some flat washers or some sort of spacer, and use a 3/8"-24 nut to draw the stud out of the recess. It's really quite easy.

A new stud can be pressed into place, but instead I would advise tapping the existing hole to 7/16"-14 and screwing in a shoulderless rocker stud (like Mr. Gasket or Elgin). These are about a dollar each. This can be done without the need for machining the stud boss flat and will not interfere with the adjustment of the rocker.

A few hints you should remember if you do this. Plug the oil drainbacks to prevent getting chips and debris in the sump. Use a magnet to pick up all the loose chips from tapping. You might want to get a new tap (about $15.00) to make the job as easy as possible. Tap one hole at a time and use the existing studs for reference marks to make sure the hole gets tapped straight and squarely in line with the others. Use a coating of LocTite 242 when you install the stud to secure it in place.

You might also consider replacing all the studs with screwed ones when you discover how easy it really is.

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Later,
Vader
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"Let the bodies hit the floor!"
Adobe Acrobat Reader

 

Thanks Vader, I'm on the case.

Cheers.

 

Nem,

If you don't feel comfortable tapping the stud holes "freehand" you can get a combination tool that is used as spacer for removing the old studs and as a guide for tapping the holes. It bolts to an adjacent stud and lines up the tap perfectly. I think I've seen them for as little as $15.00 in Jegs, Summit, etc. Comp Cams has one (P/N 5306) that makes the task about as simple as it gets. I've done them freehand with good sucess, using a straightedge clamped to adjacent studs as a guide.

Either way, the fixture, tap, and stud kit would be a lot cheaper than having one of the studs pressed in at a machine shop. For $50.00 or less you have the screwed studs, and always have the tools to do it again.

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Later,
Vader
------------------
"Let the bodies hit the floor!"
Adobe Acrobat Reader

 

Got it done tonight. Managed to borrow a really good tap set from the workshop at work. The stud cost me $3US!! Joys of being at the end of the earth.The coolant that came up through the stud hole gave me a surprise.

I replaced the pushrod and rocker as well but there seems to be quite a bit of side to side movement possible with that particular rod compared with the others. I wonder if this is what has caused the stud failure? There is no guide just the cast hole thru the head.

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83 Berlinetta - LG4, Mr Gasket Shorty Headers, Custom Y pipe, 3" pipework, 3" Vortech Muffler, Performer Intake, Open Element, QJet mods. Best 1/4 Et 15.11 @ 90.4 mph, 2.097 60ft.

 

That tap guide from Jegs is a joke. It works as a good stud puller, but as for tapping the idea sounds good to align the tap with a threaded hole thats referenced with a 3/8" pin to the bore next to it, but in reality it snapped a very expensive tap I owned (free) because running a tap through a threaded hole into a non-threaded hole will pick up and bind the tap. It snapped (more like chipped) the end of my tap on the 1st hole. I did the rest freehand with a new tap (same kind).

And as referring to free, I'm a machinist and these taps run the company $35 (You should see the costs of the bigger taps!) and a run through thousands of holes by a machine that could sure as hell spin alot faster than I could tap by hand... and never snap. (They're clutched also, but I didn't force the tap!)

These taps are like glass, the never dull (eventually, not more holes than you'd tap in steel (even grade 80) in your lifetime) just shatter.

Still.. of my tangent... Thats a overpriced stud puller!