When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
One of the rocker studs on my 81 f100 300 pulled up a half inch. I don't have the time or money right now to remove the head and do a rebuild. Nothing seems to have excesive wear, and none of the pushrods seem bent. I want to remove the stud, coat the new one with some loctite and tap it into place with the nut on the top. Does anyone have any tips for removing the old one? When I have the time and money i'll probably overhaul the valvetrain, but I can't right now.
There has to be some kind of puller that can be used with the head still on the engine. Most of the machine shops I've been around have a rather bulky device for removing those studs, since replacing them with screw-in studs is pretty common during a valve job. Most of those devices would be rather difficult to use under the hood, though.
You could try building something. Use a flat piece of steel, add a couple "legs" to each side, and a hole in the middle. Place that over the stud, and thread the rocker nut back on, then tighten it down to pull the stud out. You may need to add an oversize spacer between the steel plate and stud, to pull it all the way out.
I managed to get it out, by putting one washer down over the stud, then an appropriate sized socket, and then more washers followed by the nut. When I removed it (cylinder 3 rocker closest to the firewall) water came bubbling up, does this stud extend into the water jacket?
Also i'd like to clean and inspect the rest of the rockers and pushrods and then torque them to spec. The haynes manual doesn't say that that you have to put each cylinder at TDC to remove and reinstall each rocker, so do you have to or not?
It's best to do this at TDC, as both valves will be closed. you can do it without being at TDC on every cyl, but it makes the adjustment a bit more time comsuming, unless yours used the style that you simply bottom out the nut/bolt.
I can't recall if the studs go far enough to reach the water jacket. Sounds plausable, though.
You have the same head I have. Yes, the studs hit water. That is why it's important to put some sealant on the stud.
For tightening the rockers/adjusting the valves: Put at tdc, put on rocker and nut, and start rolling the p.rod back and forth between thumb and forefinger as you slowly tighten the nut. When you first feel resistance on the p. rod (it gets slightly more difficult to roll) that is zero lash. Look in you book. Mine says to give it a 360 degree turn after zero lash. I give it just a quarter turn. If the lifters clatter, I give 'em a quarter more. A full turn seems like a lot to me.
Clean you p.rods with paint thinner, and blow air through them. Roll them on a piece of glass to see if they are straight. Put a dab of assembly lube on each end before reinstalling. I like to cover the valve tip with lube too.
Well I removed everything, for cleaning, and bagged everything to keep track of where it came from. I have another one that is very slightly pulled up, but it has a deep groove worn into the side of it. The ford guru at my local parts place says I should just tap the holes with the head on, and switch to threaded studs. I do have a powerful magnet I could place beside the pedistal to catch shavings, but I don't know........
Interesting, mine have the round fulcrum and nut on top (and is an '81). About....maybe 2 1/2 years ago, I replaced all my lifters and had to tighten the rocker arms back down. I spent hours doing the method F-250 described above, over and over, and each time it would clack horribly and loosen back up. I finally threw in my hat and was going to have it towed to a shop to do it. Called the guy, and he told me that it didn't work that way and I just had to torque each one down to 25 ft/lbs. I did that and it fired up quieter and smoother than it's ever been. I haven't had an issue in several years.
Switching to screw-in studs is one way to insure they never pull out again.
I'm not sure when the switch was made to the ones that were just tightened all the way down, but I know it occured. I believe the style which you tighten down all the way have a shoulder for the pivot to seat against, but it's been too long since I did anything with those, other than have them switched to the screw in type.....
If switching to the screw in studs, certainly follow F250's advise on adjusting them.
Well I didn't want to question the advise everyone provided here, but the guru at my shop said the same thing. The haynes manual also shows the pic for these and says to just tighten them down to 20-25. I'm not trying to cause a fuss or anything, but could someone tell me for sure?
If simply replacing the stud with a factory style, then follow what the book and your "guru" says.
If you tap the holes, and go to screw in studs, use the method detailed above.
You won't step on toes or make enemies by questioning and double checking what people have to say. It's your engine, and no one here is going to claim responsibility for it if something goes wrong, so double check, and triple check if necessary.
Everyone just wants to see you do it correctly. This is interesting. I have an '81 head. The studs were changed to screw ins, on which I originally ran the oe rockers, adjusting as the book said, and as I stated above, and never had a problem.
Good luck.
I believe the style which you tighten down all the way have a shoulder for the pivot to seat against,
That would make sense. Mine simply ride on the stud, 'floating' with tension applied to valve/p.rod/lifter. If there is nothing to torque it to, then obviously torquing to 25lbs on the valves/p.rods/lifters could not be a good thing? I would certainly want to know before applying 25lbs preload and starting it up.