Valve lash adjustment made it worse!

[farmerfred]

My truck's had a ticking sound that doesn't go away after it warms up. Today I adjusted the valve lash per the factory manual, thinking that might help. The ticking is now worse. I plan on checking the lash again, but I think I got it right. I figure at least now I know it's the valve train that's making the ticking. Is it possible that I set the lash correctly but because of some other problem, it sounds worse? Any help would be greatly appreciated! (BTW, it's a '72 C20 w/a 350).

[1BadSS]

Sounds like you've loosened the rockers too much and now they're clattering.

[farmerfred]

Thanks, 1BadSS. That makes sense to me. The factory manual said to snug up the rocker arms 1 full turn after obtaining 0 lash. I know that lots of other people say 1/2 turn, so I tightened them less than 1 full turn. I should've known better. Thanks!

[1BadSS]

Originally Posted by farmerfred

Thanks, 1BadSS. That makes sense to me. The factory manual said to snug up the rocker arms 1 full turn after obtaining 0 lash. I know that lots of other people say 1/2 turn, so I tightened them less than 1 full turn. I should've known better. Thanks!

Well, are you doing it with the motor running or not? I have a set of valvecovers with the middles cut out so I can slap 'em on the truck and run it while i'm adjusting the rockers. I usually back them off til it clatters then bring it down til it just stops then do a full turn after that.

With the motor off, you have to make sure the cam isnt lifting the valve you're trying to adjust, or you can either flatten the lobe or it'll clatter because you're adjusting it too loose while it's at lift.

Check out the haynes manual on chevrolet smallblock building, it'll tell you EXACTLY how to adjust the valves with the motor off.

This is a Hydraulic flat tappet cam right?

[farmerfred]

I'm doing it according to the factory manual, which has you do it with the motor off. I was really careful to follow the directions about which arms to adjust at what point, so I don't think I flattened a lobe. I'm pretty sure you're right about things being too loose. I was so worried about over tightening that I didn't think about the consequences of not tightening enough. This was the first time I did this. I'm sure it will go much faster the next time.

Funny you mentioned the Haynes smallblock building manual. I was looking at it on Friday when I picked up a gasket scraper. Probably should've bought it, too.

[kwmech]

I've adjusted them both ways for years and prefer to adjust them while the engine is running. I think it is more accurate.

[1BadSS]

Originally Posted by kwmech

I've adjusted them both ways for years and prefer to adjust them while the engine is running. I think it is more accurate.

I like doing it that way too, but I wouldnt suggest someone doing it for the first time on their own. I'd suggest that they have someone who know's what they're doing helping them.

[stllookn]

I have seen 1/2 turn and 1/2 to 1 full turn after the lash has been taken up. Summit sends info with their cams that say 1/2-1 and the after market books like Lingenfelter and Vizzard say 1/2. Since I have a Summit cam and lifters I am using their specs.

I used to do my solid lifters with the engine running and did not like the mess and burns...LOL! I wish I would have thought about those 1/2 valve covers then!

[qksilver]

How do you adjust solid lifters with the engine running?

[jhow66]

With a feeler gauge and a rachet.(gauge between rocker and valve tip) You just tighten until you feel a tug on the gauge. Much easier with engine off with a solid lift cam. The settings ( such as intake .024-exhaust .026) are given for engine at normal temp. Just get them close to warm engine and the set as the cam calls for. The way I do it is on a cold engine I set them about .002 looser as they expand when hot-then recheck when hot with engine off.

[casterbuster]

I also wet set my valves, but I only load the lifter a 1/4 turn after silent. I think it is better to be a little looser than a little tight.

You may also check and see if you have a rocker arm nut backing off, I have seen this many times and it seems like they get worse after you run the valves. Sometimes you can set them and then actually watch them backing off as the engine runs. Just something you might check, nothing more annoying than chattering valve train

[68cajun]

You may also want to check and make sure you don't have a rocker stud pulling out of the head. Thats happened to me before. Lay a ruler across the top of the studs and check that they are close to even.

[farmerfred]

Thanks, 68cajun. I'll check out the studs when I redo the lash. I appreciate everyone's help!

[Billla]

I'm a 1/2 turn + cold + engine off guy myself; never had any problems to speak of. I did used to have a set of cut valve covers and little clips that would deflect the oil from the pushrod, but frankly found it a hassle and a bit of a mess.

[farmerfred]

Billa got me thinking. Maybe I should explain what I did, and maybe some can point out my mistake.

The factory manual says: "Back out adjusting nut until lash is felt at the push rod then turn in adjusting nut until all lash is removed. This can be determined by checking push rod side play while turning adjusting nut. When play has been removed, turn adjusting nut in one full additional turn (to center lifter plunger)."

Here's what I did: Loosened the rocker arm nut until I could spin the pushrod easily. While spin the pushrod, I tightened the rocker arm nut. Once I felt some drag on the pushrod, I tightened the nut one full turn. Since I've read so many people saying 1/2 turn, I probably gave each nut only 3/4+ turn. Right now, I'm thinking that I should've given each nut a full turn, but if anyone sees any other mistake, please let me know.

[farmerfred]

I readjusted the lash today, and 1BadSS was right. I had left things too loose. Runs just fine now, no ticking. Thanks to 1BadSS and everyone else who helped! Happy Thanksgiving.