Whats Going On????!!!!! - The 1947 - Present Chevrolet & GMC Truck Message Board Network

chevjayfsd · 10-17-2002, 07:17 PM

Yesterday after school I went to my truck, and I heard a rocker loose in the head so i took the valve cover off when i got home, found the loose rocker, tightened it, then everything was fine. THEN AFTER SCHOOL TODAY!!, I went to it and started it up and the same thing with the same rocker????!!!??? what is that??? is something wrong???
Ideas??
Thanks
Jason

*Zkast* · 10-17-2002, 07:22 PM

While you have the valve cover off, lay a straight edge (or something close) across the rocker arm studs. I bet you'll find one thats pulling up on you. Each time you adjust the rocker its fine until that rocker pulls the stud up a bit more.

If this is the case, you can buy oversized studs, knock a new one in and your all set.

The other possibility is a lobe going flat on the cam which is dishing out the bottom of the lifter (causing more and more valve lash) If it's still running ok after the valve adjustment, chances are the cam/lifters are in good shape.

bigjimzlll · 10-17-2002, 07:23 PM

could be a couple of things...bad lifter(doubt that) rocker stud is pulled up,check the hieght compared to others or the most likely cam lobe going flat..you might want to look at the pushrod..see if the ends are messed up, also check the rocker where the pushrod goes into..if it turns out to be the cam lobe..dont drive it ...the cam guts do very bad things to bearings

bigjimzlll · 10-17-2002, 07:25 PM

boy zkast..you sure are smart....lol.. we must of posted at the same time

*Zkast* · 10-17-2002, 07:25 PM

lol same answer at almost the same time

Alaskan · 10-17-2002, 07:29 PM

Could be a couple of things. Rocker stud is sliping, bent push-rod, collapsed lifter. I'd bet it's a pulled rocker stud. To check lay a straight edge on the top of the studs.

Alaskan · 10-17-2002, 07:31 PM

Must be some fast fingers out there. All good advise.

**JDL** · 10-17-2002, 08:37 PM

it might be just a bad nut that works its silf lose

Jwill41 · 10-19-2002, 03:24 PM

i had an old pontiac one time that i had to replace the nuts on the rocker arms. no problems after that. i think they are tapered nuts and after a few times on and off they dont stay tight any more.

10-17-2002, 07:17 PM	#1
chevjayfsd Project 7dos Join Date: Aug 2001 Location: Abilene, Texas Posts: 876	Whats Going On????!!!!! Yesterday after school I went to my truck, and I heard a rocker loose in the head so i took the valve cover off when i got home, found the loose rocker, tightened it, then everything was fine. THEN AFTER SCHOOL TODAY!!, I went to it and started it up and the same thing with the same rocker????!!!??? what is that??? is something wrong??? Ideas?? Thanks Jason __________________ 7DOS - 1972 C-10 350/350 Porterbuilt/Accuair 20x8.5/20x10 Ride Low or Die PSSST - Yes it's bagged. 7dos build thread: http://67-72chevytrucks.com/vboard/s...d.php?t=610290

10-17-2002, 07:23 PM	#3
bigjimzlll Senior Member Join Date: Dec 2001 Location: Redding,CA...USA Posts: 4,736	could be a couple of things...bad lifter(doubt that) rocker stud is pulled up,check the hieght compared to others or the most likely cam lobe going flat..you might want to look at the pushrod..see if the ends are messed up, also check the rocker where the pushrod goes into..if it turns out to be the cam lobe..dont drive it ...the cam guts do very bad things to bearings __________________ It's called "drag racing" if they called it "tic..tic..WHAM!..BANG! F*&K!!!", they'd have to keep the magazines under the counter with the other men's publications click the clicky to join the site.... http://67-72chevytrucks.com/vboard/payments.php 67 lwb..first hotrod in 25 years..540 best ET is 9.45 @ 141.44 Anderson,CA

10-17-2002, 07:25 PM	#4
bigjimzlll Senior Member Join Date: Dec 2001 Location: Redding,CA...USA Posts: 4,736	boy zkast..you sure are smart....lol.. we must of posted at the same time __________________ It's called "drag racing" if they called it "tic..tic..WHAM!..BANG! F*&K!!!", they'd have to keep the magazines under the counter with the other men's publications click the clicky to join the site.... http://67-72chevytrucks.com/vboard/payments.php 67 lwb..first hotrod in 25 years..540 best ET is 9.45 @ 141.44 Anderson,CA

10-17-2002, 07:29 PM	#6
Alaskan Truck'n the alcan Join Date: Jan 2001 Location: Houston, AK Posts: 149	Could be a couple of things. Rocker stud is sliping, bent push-rod, collapsed lifter. I'd bet it's a pulled rocker stud. To check lay a straight edge on the top of the studs. __________________ 68 GMC 4x4 71 C20 Custom Deluxe 83 1/2 ton conversion van

10-17-2002, 07:31 PM	#7
Alaskan Truck'n the alcan Join Date: Jan 2001 Location: Houston, AK Posts: 149	Must be some fast fingers out there. All good advise. __________________ 68 GMC 4x4 71 C20 Custom Deluxe 83 1/2 ton conversion van

10-17-2002, 07:22 PM	#2
Zkast Account Suspended Join Date: May 2002 Location: Olathe, Kansas Posts: 929	While you have the valve cover off, lay a straight edge (or something close) across the rocker arm studs. I bet you'll find one thats pulling up on you. Each time you adjust the rocker its fine until that rocker pulls the stud up a bit more. If this is the case, you can buy oversized studs, knock a new one in and your all set. The other possibility is a lobe going flat on the cam which is dishing out the bottom of the lifter (causing more and more valve lash) If it's still running ok after the valve adjustment, chances are the cam/lifters are in good shape.

10-17-2002, 08:37 PM	#8
JDL Senior Member Join Date: Sep 2000 Location: Agency IA. Posts: 1,839	it might be just a bad nut that works its silf lose __________________ 72 Chevy short step side with 454 air and tilt. 72 nova project car 63 chevy II drag car Agency Iowa

10-19-2002, 03:24 PM	#9
Jwill41 Registered User Join Date: Aug 2002 Location: Farmers Branch, Tx Posts: 1,009	i had an old pontiac one time that i had to replace the nuts on the rocker arms. no problems after that. i think they are tapered nuts and after a few times on and off they dont stay tight any more. __________________ http://www.picturetrail.com/jwill41 67 1/2 ton GMC short step side 68 1/2 ton Chevy long fleet side 72 1/2 ton Chevy Suburban 99 1/2 ton Chevy Suburban founder (and only member) of the primer/clearcoat club Last edited by Jwill41; 10-19-2002 at 03:29 PM.



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