Mechanics

CHEVROLET LUMINA ROCKER ARM PROBLEM

1991 Chevrolet Lumina • 291,868 miles

I have a 1991 Chevrolet Lumina with a 3.1L V6. The timing chain broke and valves were bent. Instill of having to have the heads repaired, I brought a set of Remanufactured Heads with new valves installed.

Yesterday I finally got around and installed the new heads. Today when I started to adjust the valves, I ran into the following problem. There is not enough threads on the Rocker Arm Studs to adjust the valves, while rotating the pushrods until valve lash is eliminated

I found out today that the original heads on my car came with rocker arm studs (valves) that were not adjustable.

The rocker arm studs on the old heads are taller than the rocker arm studs on the new heads.

How do I fix this problem? Do I need to buy some Adjustable Rocker Arm Studs to replace the Short Rocker Arm Studs on the new heads?
Asked by Pilotbill

Answer
Replied on November 09, 2012
You need to get the correct heads for the engine, it will cause bent pushrods or worse trying use the wrong heads. Your pushrods are different lengths. Thanks for using 2CarPros
Answered by mekanic4755 (expert)

(Question)
I called the Auto Parts Store already and asked them if the heads I brought were the correct heads for my car, they told me that all heads has a casting number on them and that if the numbers match, then they are the correct heads. The numbers on my old heads match with the numbers on my new heads. The only difference between the heads were that on the old heads the rocker arm studs were a little taller, on the new heads, they are a little shorter. I know the pushrods are difference in lengths.

What do I need to do to fix this problem so that I can adjust my valves? Do I need to remove the short rocker arm studs from the new heads and replace them with the new Adjustable Rocker Arm Studs?

Thank You
Avatar
Pilotbill
November 9, 2012.



Make sure you have the right spuhrods inteh correct place first intake push rods are shorter than exaust push rods. They may be marked with orange paint for intake and blue for exaust.

Hmac300
Nov 9, 2012.