What zero lash on the lifter rod should feel like?

Disclaimer: Links on this page pointing to Amazon, eBay and other sites may include affiliate code. If you click them and make a purchase, we may earn a small commission.

Hugomartin

Banned
Joined
Jul 23, 2021
Posts
256
Reaction score
71
Location
Nc
First Name
Hugo
Truck Year
1987
Truck Model
V20 3/4 ton 5.7 350 suburban
Engine Size
350
Should I be able to still barely spin the rod with my fingers then 1/2 to3/4 turn?
 

DoubleDingo

Full Access Member
Joined
Jul 3, 2012
Posts
11,321
Reaction score
17,359
Location
Right where I am
First Name
Bagoomba
Truck Year
1981
Truck Model
81-C20 Silverado Camper Special-TH400-4.10s
Engine Size
Carb'ed Vortec 350
Use one finger and slide the side of it perpindicular to the push rod, and when the rod won't rotate anymore you're at zero lash. Using two fingers you can still rotate it at zero lash.
 

Bextreme04

Full Access Member
Joined
May 13, 2019
Posts
4,463
Reaction score
5,626
Location
Oregon
First Name
Eric
Truck Year
1980
Truck Model
K25
Engine Size
350-4bbl
Should I be able to still barely spin the rod with my fingers then 1/2 to3/4 turn?
No spin. It will be able to freely spin and then when it hits zero lash you will feel it get very tight. Then I do 1/2 turn. I use the EOIC method. It makes it super easy, especially if you have a starter trigger switch to bump it over.

xc_hide_links_from_guests_guests_error_hide_media
 

75gmck25

Full Access Member
Joined
Oct 13, 2016
Posts
2,302
Reaction score
2,271
Location
Northern Virginia
First Name
Bruce
Truck Year
1975
Truck Model
K25 Camper Special TH350 NP203
Engine Size
5.7
I have also seen suggestions that jiggling the rod up and down is easier to feel the zero point. When you go up and down it’s a simple go/no go choice (does it move). When you spin the rod you need to calibrate the “feel” of your fingertips to know how hard it is to rotate. YMMV.
 

Hugomartin

Banned
Joined
Jul 23, 2021
Posts
256
Reaction score
71
Location
Nc
First Name
Hugo
Truck Year
1987
Truck Model
V20 3/4 ton 5.7 350 suburban
Engine Size
350
I tried adjusting the rocker arms but still no start
i can only seem to charge my battery to 12.1v . After a couple times trying to crank it drops to 11.6v.
 

DoubleDingo

Full Access Member
Joined
Jul 3, 2012
Posts
11,321
Reaction score
17,359
Location
Right where I am
First Name
Bagoomba
Truck Year
1981
Truck Model
81-C20 Silverado Camper Special-TH400-4.10s
Engine Size
Carb'ed Vortec 350
Sounds like the battery is in need of replacement
 

Bextreme04

Full Access Member
Joined
May 13, 2019
Posts
4,463
Reaction score
5,626
Location
Oregon
First Name
Eric
Truck Year
1980
Truck Model
K25
Engine Size
350-4bbl
I tried adjusting the rocker arms but still no start
i can only seem to charge my battery to 12.1v . After a couple times trying to crank it drops to 11.6v.
Where are you measuring that at? At the battery, you should have ~12.7v for 100% charge. 12.1v is less than 50% charge. 11.6v is basically dead. Do you have it on a battery charger and it won't go above that? Are you just reading it at the dash?
 

Hugomartin

Banned
Joined
Jul 23, 2021
Posts
256
Reaction score
71
Location
Nc
First Name
Hugo
Truck Year
1987
Truck Model
V20 3/4 ton 5.7 350 suburban
Engine Size
350
Where are you measuring that at? At the battery, you should have ~12.7v for 100% charge. 12.1v is less than 50% charge. 11.6v is basically dead. Do you have it on a battery charger and it won't go above that? Are you just reading it at the dash?
Yes I was measuring it at the battery. Thanks for the info I didn’t know 12.1 was only 50%, below is my jump starter I used to charge my battery. It’s definitely a step down from a real battery conditioner charger
 

Attachments

  • E82BF64E-FDFE-4A25-A4CD-71FEE7456131.jpeg
    E82BF64E-FDFE-4A25-A4CD-71FEE7456131.jpeg
    129.4 KB · Views: 39

squaredeal91

Full Access Member
Joined
Mar 10, 2023
Posts
2,583
Reaction score
4,697
Location
Cave junction Oregon
First Name
Greg bush
Truck Year
1991 SB
Truck Model
K30
Engine Size
5.9 Cummins 12 valve
I've only adjusted chevy rockers while running. But reading this has been interesting, I think I'll try this method next time soon.
 

squaredeal91

Full Access Member
Joined
Mar 10, 2023
Posts
2,583
Reaction score
4,697
Location
Cave junction Oregon
First Name
Greg bush
Truck Year
1991 SB
Truck Model
K30
Engine Size
5.9 Cummins 12 valve
You can probably have your battery charged for free at the local parts house.
 

Hugomartin

Banned
Joined
Jul 23, 2021
Posts
256
Reaction score
71
Location
Nc
First Name
Hugo
Truck Year
1987
Truck Model
V20 3/4 ton 5.7 350 suburban
Engine Size
350
Update , I tried using jumper cables from a donor vehicle and I measured voltage and got 12.7 v with a multimeter on the square body battery but still crank and no start I hear some spark popping noises and it turns over fine just no start... I guess we can rule out a bad battery

I played with the lash settings tightening the pushrods/lifters as I was turning the engine by hand making sure of no play then going a 1/4 turn.

I think I’ll re check my compression on dead cylinders 4,6,8
 
Last edited:

squaredeal91

Full Access Member
Joined
Mar 10, 2023
Posts
2,583
Reaction score
4,697
Location
Cave junction Oregon
First Name
Greg bush
Truck Year
1991 SB
Truck Model
K30
Engine Size
5.9 Cummins 12 valve
Sounds like you are now trying to diagnose a no start? How's spark, is it orange or blue ? Is there fuel squirting?
 

Rickf

Full Access Member
Joined
Jul 29, 2017
Posts
574
Reaction score
716
Location
Grafton NH
First Name
Rick
Truck Year
1974, 1954 & a 1937
Truck Model
K20
Engine Size
350
Was it running? What if anything did you mess with? If your lash is too tight, you will have starting issues.
 

DoubleDingo

Full Access Member
Joined
Jul 3, 2012
Posts
11,321
Reaction score
17,359
Location
Right where I am
First Name
Bagoomba
Truck Year
1981
Truck Model
81-C20 Silverado Camper Special-TH400-4.10s
Engine Size
Carb'ed Vortec 350
Not sure what method you used, but this is the method in the book. Except I don't turn 1 turn, I go 1/2 turn. You can turn 1 turn, but I have had issues with 1 turn before, since then it has been 1/2 turn

You must be registered for see images attach





You must be registered for see images attach
 

DoubleDingo

Full Access Member
Joined
Jul 3, 2012
Posts
11,321
Reaction score
17,359
Location
Right where I am
First Name
Bagoomba
Truck Year
1981
Truck Model
81-C20 Silverado Camper Special-TH400-4.10s
Engine Size
Carb'ed Vortec 350
Was it running? What if anything did you mess with? If your lash is too tight, you will have starting issues.
YUP. As I mentioned in my previous post, when I went 1 turn and had issues, it started and ran but the vacuum gauge was bouncing all over the place, so I had to redo them all at 1/2 turn and the vacuum gauge was then steady at 17Hg
 

Forum statistics

Threads
44,390
Posts
956,227
Members
36,676
Latest member
sv_2323
Top