In slow process of reassembling my 455. Decided good insurance to replace all the rocker arm buttons. Was surprised to see the wear on the bottoms of my TA thick walled shafts from the rocker arms. Why does this happen? Normal metal to metal? Lack of oil? Figure ok to reuse...
Was running Royal Purple HPS....suppose to have high levels of zinc. Spring pressures.....hmm....they are stage 1 springs....the insides of the rockers also looked worn. I do have a new full set of rockers that I will use. Just not sure on shafts. Should they be polished a bit?
Yes and yes. The pushrods are slightly shorter than stock, 9.325 due to block and heads milled. These shafts have about 5 years on them....maybe 6000 miles
I dont see any way to prevent this from happening given the way the set up is......spring and pushrods shoving the rocker up and sliding across the shaft.....but in 6000 miles seems soon.......but wouldn't take long on a dry break in to cause this. How deep is the groove, are you running a big cam?
Looks a little excessive for the miles, but there are a lot of factors that come into play. Can the shafts be rotated 180 degrees and start with a fresh side? Might be time to switch to rollers.....
I'd call Mike at TA and ask him what he thinks. I agree with dry when broke in. Bring them to a crank grinder and get them polished.
Thanks guys. I will call TA. Running ta 284 88h. I snapped one of the stock shafts. These are much stronger. Rotating a great idea, but the holes for the nylon buttons are only on one side. It is a rather sloppy set up when u think about it....the rockers are so loose and clink around before installing. Perhaps....one reasons I pulled motor was extremely low oil pressure @ idle only.....maybe caused when it would be at idle. Oh well....always a guessing game
Were you using a pushrod with a very tiny oiling hole........if so low pressure and tiny passage could had led to lack of oil up there
Hot @ idle....at a light....would be around 3 or 4 psi this past summer. Off idle it was incredible....responsive and always 20 psi above whatever the rpm was. Pushrod....are TA pushrod....super quality pieces.
As was mentioned, that wear could happen on initial start up. You have to be careful with that rocker set, it's not possible to lube them after they are installed.. you have to do it before they are installed, to get the oil between the shaft and the rocker. And less than 5 psi at idle is certainly a factor in that wear. If you cannot catch your nail on that wear, then just polish it up and put your new rockers on it.. if you can catch your nail on the wear, then it's time for a new pair of shafts. JW
When those shafts were new...were the rockers also new? Installed as a set? Or were the shafts new, and the rockers already wiped-out, scored, worn? If the rockers were already damaged, they caused the excess wear on the shafts.
Trying to think back.....I believe I may have used installed the my used rockers onto these new shafts, yes. One if the e stock shafts I put when I built the motor snapped. So yes, that may have been a major contributor. Unfortunately, TA is out of stock on these shafts, with no real estimate of when.
Thanks for the link, but TA is out of stock of the thick heavy duty shafts, which is what mine are. I already snapped a stock one. I do however use the black roller clamps, do the hold down clamps make the stock shafts just as strong?
You could always order a thick wall tube and any good machine place should be able to take your old on and punch tbe holes in the correct spots and size
