The Stovebolt Site Forums The Shop Area Engine Shop Pushrod Question

I have the valvetrain out of my engine, rockers and shafts were wiped, new ones to be ordered. Anyway, there are definately a few pushrods that are obviously worn out at the rocker adjuster end but the lifters and lifter ends look OK. Aside from the obvious and being bent what are other signs that the pushrods needing to be replaced. Hoping not to replace all of them. Thanks!

Please don't trash the old rockers and shafts- - - - -they can be refurbished. I regrind the shafts to a smaller diameter (18MM) and ream the rocker arms for Torrington needle bearings. Drop me a private message, and we can discuss shipping costs, etc. to get the "discard" parts recycled. Thanks!

The top ends of the pushrods are the most common failure areas. The cupped part where the rocker arm adjusting screw fits can wear unevenly, and cause damage to the adjusting screw- - - -resulting in inaccurate valve lash. If the rocker screw tips have a projection worn into the middle, they will cause wear or damage to the top cup on the pushrod, and sometimes even break the cup area.
Jerry

On a couple of rocker adjustment screws I do see the "projection" you note. You phrased it nicer than me. I was thinking more like the tips were "wet T-shirt contest like" Anyway, I did notice that in the cup of the pushrod on 2 of them the little recessed dimple is worn away. Those were the worst. 2 others seemed discolored but the dimple was mostly there, is that a bad sign?

The shafts were real bad, where the rocker wears on the bottom of the shaft the wear is .050-.060 or more on several locations. Rocker bores were egg shaped, anywhere from .015-.035 out. A vendor was having a 250th birthdat sale over the weekend so for $424 shipped I ordered shafts and 12 (3 of each) rockers. When I get everything sorted out I'll get in contact and see if they are something you can use. Thanks!

Since the rocker shafts only wear on the bottom, the shade tree fix used to be to turn them upside down. That puts the lube holes in the wrong position, so it was a temporary fix at best. Since I grind the shafts to a smaller diameter, the wear is usually a moot point. Ditto for the rockers- - - - -the Torrington bearing housings require the rockers to be reamed about .060", so any wear there is also removed.

A valve train worn that badly is a pretty good sign of little or no oil flow to the top end. Be sure to find and fix the oil supply problem, or you'll just be putting a band aid on a brain tumor!
Jerry

so i'm interested in your modification of the rocker assembly, how much and what kind of turnaround are we looking at.
THANKS Jay D.

Let's take this conversation to a private message- - - -I really don't want to get 40 lashes with a wet noodle from the PC Patrol for getting "commercial" on the forum! I'm not taking on any outside work right now due to family health issues and limited shop time availability, but I'd be glad to consult with a machinist in your area who's willing to do the job.

Here's the bearing I use 18 X 24 X 16 MM- - - -2 per rocker arm- - - -24 total:

www.ebay.com/itm/356988169407?

Jerry

Hotrod, we are on the same page with the oil flow issue. Bought the truck about 7 years ago. A running, driving truck. BUT when it ran the engine was "Clackity". I hoped it was a valve adjustment since I'm new with these older engines so I just let it ride until the restoration began 2 years ago. I also noted that the timing gears looked drier than I thought they should be even though the engine sat for a while. Given the amount of driving I did I think the damage was done. Anyway, Once I get my new rear main seal in I'll get the oil pan on and try to circulate oil. Will do it with all the covers off to confirm. Will probably be a mess. So excited...