Valve seals replacement help

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Apr 22, 2020 | 09:04 AM

#61

84 4+3

Le Mans Master

Joined: Aug 2017

Posts: 6,930

Likes: 1,487

From: New Jersey

I already said I was sorry for being wrong guys... as far as the adjustment, it's the way I was taught some 15 years ago and the way dad learned it at merc school some 35 years ago and taught it to me... Like I said... I'm an ***. I'm wrong. My bad. I get it. Don't rub it in anymore... atleast I now know what I thought was right was wrong. I appreciate that being set straight.

Apr 22, 2020 | 12:19 PM

#62

Theman5

Pro

Joined: Mar 2020

Posts: 500

Likes: 27

Quote:

Originally Posted by 84 4+3

Did I miss something ?

Apr 22, 2020 | 12:46 PM

#63

mtwoolford

Melting Slicks

Joined: Jan 2009

Posts: 3,482

Likes: 195

From: folsom california

Quote:

Originally Posted by Bfenty

I mean, the definition of 'tight' in the FSM is when you can't ROTATE the pushrod, not when you can't lift it up and down. I'm not saying you're wrong, but I did follow the FSM procedure to the letter. I agree that doing exactly that led to it being overtightened.

From the FSM for 96 (but applicable to all models), at pages 6-138, 6-139 :

7. Adjust the valve rocker nuts until all of the lash is gone.
7.5.1 Back off the valve rocker nut until the lash is felt in the valve push rod.
7.5.2 Tighten the valve rocker arm nut until all lash is removed.
7.5.3 Zero lash can be felt by moving the valve push rod UP and DOWN between your thumb and forefinger until there is no more movement.
7.5.4 When all free play is gone tighten the valve rocker arm nut 1 additional turn...

Apr 22, 2020 | 01:26 PM

#64

84 4+3

Le Mans Master

Joined: Aug 2017

Posts: 6,930

Likes: 1,487

From: New Jersey

Quote:

Originally Posted by Theman5

Did I miss something ?

The whole adjustment discussion. It's not a big deal and now I know so I don't go repeating false internet lore.

Apr 22, 2020 | 03:39 PM

#65

Joe C

Race Director

Joined: Aug 2000

Posts: 11,470

Likes: 763

Quote:

Originally Posted by Bfenty

Bf - (just my opinion) I think you may be mis-interpreting the service manual. IF I'M NOT MISTAKEN, in so many words, it says, (to set zero lash) ...rotate the pushrod, using your thumb and forefinger and adjust the nut UNTIL RESISTANCE IS FELT, then adjust the nut 1 full turn.... big difference between "can't rotate" and resistance felt. if you are adjusting the pushrod until you can't rotate it, IMO, you've gone way too far. I mentioned earlier that I use a .0015 feeler gauge to set (near) zero lash. personally, I have better feel for feeler gauge drag, than rotational resistance. for years I did the rotate thing - don't know if I lost my feel or what, but about 15-20 years ago, had one cylinder that gave me fits - out of desperation, grabbed the feeler gauge, and the rest is history. been doing it that way ever since. in the big scheme of things, insignificant difference between zero and .001 lash.

in the original discussion, i'm assuming, we were talking first gen small blocks. LT's, marine applications, or whatever, might be mixing apples and oranges....

Last edited by Joe C; Apr 22, 2020 at 04:07 PM.

Apr 22, 2020 | 04:33 PM

#66

Bfenty

Thread Starter

Drifting

Joined: Mar 2017

Posts: 1,897

Likes: 164

From: Nashville TN

2017 C4 of Year Finalist

Quote:

7.5.3 Zero lash can be felt by moving the valve push rod UP and DOWN between your thumb and forefinger until there is no more movement.

Quote:

I think you may be mis-interpreting the service manual

setting the record straight, here is the manual page. I probably mis-interpreted it because it says to rotate the rod and stop when play is removed. I assumed that meant, "can't rotate anymore" but that's up to interpretation. Regardless, it runs now with no issues, so...I'm happy. Ready to move on to chasing the next issue-it hunts for idle a bit until 140 degrees when the sensors kick in. Not even sure where to begin troubleshooting that one...