Pesky little Rocker buttons

I know most people recommend replacing these little plastic parts when doing any serious head work, but is it really necessary? Do they really fail once in awhile?

I ruined four new ones trying to replace just two of them. Tapping them into their little holes just shredded the grabber threads and it was easy to pull them back out by hand. They are the Federal-Mogul brand.

The temperature was 50 degrees in my shop so I thew a couple of new ones in boiling water for a few minutes. This time they went in without serious damage but still are not as tight as the old ones.

All the remaining old ones seem at 125 k miles seem nice and snug.

If I really should replace them, I think I'll bring the rockers into the house and heat them up along with the buttons in order to make them go in without damage.

You're doing the right thing by warming the new nylon rocker retainers before pressing them into the rocker shafts.

I admit that I've not replaced the rocker retainers when building an engine, but it's best that you do (and I would too if doing it again).

Jim

dThanks for the advise. Brought all of them into the house and boilded the new rocker guide buttons toget them hot along with a little 15-40 oil. Alowed the old shafts to get to room temp or a little higher on the wood stove.

Pulled the old buttons with wife's help and had her steady the shafts for installation of the new ones, two old out and two new in at a time. From the hot water, I tood the new buttons and dipped them into the hot oil. Then installed them and they went in like silk, but there were still some particles left from removal of the old and installation of the new. If particles get into the engine they'll probably get caught by the oil filter right? Watch for old debris from the old buttons lodging inside the rocker shafts, and also debris from installation of the new buttons under the button tops - I found one big piece and blew it out with the air CP, but several small slivers as well lodged under the new button tops. Probably all of them would have washed into the pan and been picked up by the filter, so I made a big deal out of nothin, but who knows? Why take the chance.