Tapping when cold and trouble shifting to first

[Praxiss454]

Hi All, Recently rebuilt my L6 230. Broke it in, and changed the oil. Running SAE30 this change with ZDDP additive.

When I first fire it up, its very tappy. I don't know if this is normal or a symptom of a misadjustment. I followed the compcams instructions to set pre load on the lifters, 3/4 turn past when the pushrod wont easily spin in my fingers.

Video of cold start: https://imgur.com/l6cKica
Video after it warms up: https://imgur.com/x6ZlTGi

Any thoughts?

My second problem is thus: It's the manual 3-speed transmission with 3OTT. Sometimes when I go to shift into 1st gear at a stop light or stop sign, it sort of jerks/thunks/grinds into gear even with the clutch pedal fully depressed. I believe this is a non-synchro transmission, but even from a dead stop this happens sometimes. What's going on? Any thoughts on how to fix it?

I've tried to double clutch, I've tried to goose the engine a touch before attempting, no dice. I don't think it's happened when switching from Reverse to 1st gear, only when downshifting from 2nd to 1st at a complete stop.

[geezer#99]

Instead of twist the pushrod, try the wiggle all the slack movement out of the rocker method. Some knuckle draggers like me can twist the rods even with the valve spring compressed.
Your shift problem could just be a need for a pedal adjustment. Tighten the linkage up a bit.

[Steeveedee]

I didn't watch the videos, so no comment there. You probably have no synchro for first if it is the original trans, so it's going to grind on a downshift. Wait until you are completely stopped before shifting to low (truck still in 2nd or 3rd gear, clutch disengaged). Check your clutch free pedal, and if that's OK, pull the trans into 2nd or 3rd before going to reverse or 1st, as that will stop the cluster gear from spinning, and you will be able to put it in those gears with no clashing.

[AcampoDave]

The ol' three speeds are touchy in the sense that if you depress the clutch, go into neutral, and release the clutch (engine running), the non-syncro first gear needs quite a bit of time at an idle with the clutch depressed before you can slip it right into first. You can avoid the delay (for instance at a long stoplight while idling in nuetral with the cutch out ) by depressing the clutch, then just moving the stick enough to kiss the syncros on second (or even third) and then a properly adjusted clutch will let you drop right into first. I do that a lot in traffic, and for a quick stop sign I just make sure I roll up braking while decelerating in third, then just before it starts to lug I depress the clutch, and keep it down until I finish stopping and it drops right in. The trouble comes when you go to neutral to rest your leg. That's when you gotta touch a synchronized gear before she'll drop in.

Regarding the lifters....when I do a static adjustment, I dont spin the pushrod but rather try to click it up and down until all the lash disappears, then take my additional quarter turn. It always seems to me that they spin pretty easy, even when they have a bit of torque on them. I still follow up with a running adjustment afterward though, backing off each one untill it clicks then slowly tighten until it just quiets down, then give it the extra 1/4 to 1/2 turn. Edit: looks like I took so long that geezer and steeveedee stole my thunder oh well....good luck!

[Praxiss454]

Folks seem to be implying that my pushrod spin method will result in me setting the valves too tight, but my symptom is more like they are too loose, right? When properly adjusted, will I still have this kind of tapping on cold starts?

[Chevy Fleetside]

That doesn't sound like a lifter. It has a ting to it.

[geezer#99]

That’s better.
Got the videos to work this time.
Cold. That’s not normal. Sounds too loose.
Hot. Still some ticking a tiny bit.
Pull the cover and set them hot running.

What weight of oil are you using?

[Praxiss454]

Originally Posted by geezer#99

That’s better.
Got the videos to work this time.
Cold. That’s not normal. Sounds too loose.
Hot. Still some ticking a tiny bit.
Pull the cover and set them hot running.

What weight of oil are you using?

Non detergent SAE 30 for 500 miles was my plan. I've read going to 10w30 or 15w40 can help with tapping when cold.

I'll pull the cover and set them when running and see how that goes.

Might also have an exhaust leak judging by the comments on ticking I guess?

[geezer#99]

When you pull the cover watch all the rockers for movement too.
Use cardboard along the sides to deflect any oil splash.
My method is to loosen each one then tighten until clicking stops, then do the rest like that. Then shut it down and adjust them all 1/4 turn more. This way your motor won’t tend to quit if a valve hangs open momentarily. And it’s more accurate.

But try some lighter oil first. Might save a mess.

[Steeveedee]

Originally Posted by Praxiss454

Hi All, Recently rebuilt my L6 230. Broke it in, and changed the oil. Running SAE30 this change with ZDDP additive.

When I first fire it up, its very tappy. I don't know if this is normal or a symptom of a misadjustment. I followed the compcams instructions to set pre load on the lifters, 3/4 turn past when the pushrod wont easily spin in my fingers.

Video of cold start: https://imgur.com/l6cKica
Video after it warms up: https://imgur.com/x6ZlTGi

Any thoughts?

My second problem is thus: It's the manual 3-speed transmission with 3OTT. Sometimes when I go to shift into 1st gear at a stop light or stop sign, it sort of jerks/thunks/grinds into gear even with the clutch pedal fully depressed. I believe this is a non-synchro transmission, but even from a dead stop this happens sometimes. What's going on? Any thoughts on how to fix it?

I've tried to double clutch, I've tried to goose the engine a touch before attempting, no dice. I don't think it's happened when switching from Reverse to 1st gear, only when downshifting from 2nd to 1st at a complete stop.

Rocker arms need adjusting. Remove the valve cover and run through the adjustment while it is running. Look for the rocker arm that is "wandering" and adjust that one a little tighter first, just enough to take the clatter out. The "wandering" will be obvious. Then, loosen each one until it makes noise, let it chatter a bit to pump up the lifter cup and then tighten the nut until it stops. If the lifter is compressed because the nut is too tight, it may take a few seconds for it to pump full again. Then, take it 1/4 turn slowly in case the engine wants to stall. Run through them all that way. Depending on what the cam manufacturer calls for turns on the nut, just run back through them from front to back, gradually tightening them slowly, 1/4 turn at a time.

[Chevy Fleetside]

So I didn't hear a ting sound? Not that I have great hearing anyway. If you have a mechanics stethoscope you might be about to pin point where the noise is coming from. Just a bit of advice, don't buy one from Harbor Freight.

[Praxiss454]

Well I tried to adjust twice while running and in addition to making a mess, i might have made it sound worse. I'm honestly tempted to just get rid of the truck. I'll try another time to set them with the engine off, manually turning the engine to find the bottom of the lobe.

[shp4man]

It goes away after running awhile - sounds like one of the lifters is going flat.

[Praxiss454]

Originally Posted by shp4man

It goes away after running awhile - sounds like one of the lifters is going flat.

Exactly what I'm afraid of. Already replaced the cam and lifters once this summer. Not willing to do it again. The truck will go if that's the case.

[geezer#99]

If you didn’t tear the motor down completely to flush all the fine metal out from the first cam failure then there’s a good chance it’s come back to bite you in the butt.

[shp4man]

Originally Posted by Praxiss454

Exactly what I'm afraid of. Already replaced the cam and lifters once this summer. Not willing to do it again. The truck will go if that's the case.

Lifters are cheap man. Just figure out which one it is and replace it.

[Praxiss454]

Originally Posted by shp4man

Lifters are cheap man. Just figure out which one it is and replace it.

Y'all know more about these trucks than me but I was under the impression one needs to replace the camshaft when a flat tappet lifter gets worn down enough to warrant replacement.

[Steeveedee]

That's the recommended method, or you'll just grind the next one down.

[AcampoDave]

Originally Posted by Praxiss454

Exactly what I'm afraid of. Already replaced the cam and lifters once this summer. Not willing to do it again. The truck will go if that's the case.

sometimes it goes that way. This hobby requires a certain amount of passion to pull thru the many frustrations involved with it. When overcoming the challenges involved feels like an unpleasant chore, one must decide if it is truly worth it. I myself am on the fence about abandoning a project truck in my garage. It needs more work than I have energy or motivation for. In my case though selling it will be a pain without any front suspension. Best of luck to you no matter what you decide.

[shp4man]

Originally Posted by Praxiss454

Y'all know more about these trucks than me but I was under the impression one needs to replace the camshaft when a flat tappet lifter gets worn down enough to warrant replacement.

Hydraulic lifters are sort of suspended by oil. You turn the motor off, the bad lifter goes flat from the spring tension. Start the motor up and the lifter is noisy till the oil gets back in it.
It runs OK when warm- that means the cam is OK.
Take off the valve cover and turn the engine over a few times- the loose rocker should be easy to find. Make sure the pushrod isnt bent.

[Praxiss454]

Sold the truck this morning. It went fast, people are thirsty for these old trucks. Thanks for the help, some day I'll get another project when my family and house situation is more conducive to it.

[Steeveedee]

Ouch. I hope you got a decent amount of money for it. People are asking incredible money for not-so-incredible trucks.

[Chevy Fleetside]

I have an extra short bed truck and a corvette lt1 engine. Maybe it is time to put another one together, and make some extra dough.