Autometer 5" Diesel Tach Issues

Cummins12Club

Cummins12Club

Happy Dinosaur
I have an Autometer 5" diesel tach and pick up sensor on my 12 valve fluidampr balancer. The tach does not read well at all, jumps around, nothing even worth looking at. I notice the instructions show a 4 notch balancer and mine is a 2 noth. What has everyone been doing to combat this issue?
 
2 things I did to combat any issue of the tach jumping.

First, I took a dremel to my Fluidampr and made 2 additional notches on the same side i had the tach pickup located. I didn't make grooves all the way across the surface of the damper, just 1" x 1" notchs IIRC.

2nd, I stuck the tach wires in a drill and twisted them together. Didn't go to crazy, just enough to get them together. I then wrapped the wires in HVAC tape from the tach pickup all the way to the back of the tach. Then wrapped that in electrical tape. The Aluminum HVAC will help dissipate the engine harmonics that cause the tach to jump in the higher RPMs.

Did that 2+ years ago and have a dozen or so hooks on the truck and havent had any issues with the tach jumping. Its as smooth as factory. Only issue to note would be the tach bouncing once i hit about 5,500 RPM right before i ride the clutch out.
 
I never was able to get mine working correctly with 2 notches. I welded 4 small bolt nuts to the balancer and has been working smooth and perfect. I just tacked the nuts on thru the open middle.
 
PVXCummins said:
2 things I did to combat any issue of the tach jumping.

First, I took a dremel to my Fluidampr and made 2 additional notches on the same side i had the tach pickup located. I didn't make grooves all the way across the surface of the damper, just 1" x 1" notchs IIRC.

2nd, I stuck the tach wires in a drill and twisted them together. Didn't go to crazy, just enough to get them together. I then wrapped the wires in HVAC tape from the tach pickup all the way to the back of the tach. Then wrapped that in electrical tape. The Aluminum HVAC will help dissipate the engine harmonics that cause the tach to jump in the higher RPMs.

Did that 2+ years ago and have a dozen or so hooks on the truck and havent had any issues with the tach jumping. Its as smooth as factory. Only issue to note would be the tach bouncing once i hit about 5,500 RPM right before i ride the clutch out.
Click to expand...

how deep did you go with the dremel? any pictures of this? I appreciate the info!
 
No pictures unfortunately. I'm out of state a for a month so its not like i can run out and snap some lol.

I want to say the notches were 1/8" - 1/4" deep.

I should probably specifiy as well, i made the notches as evenly spaced as possible between the existing slots in the Fluidampr. Basically take a circle and place 4 points evenly spaced around the circumference.
 
PVXCummins said:
No pictures unfortunately. I'm out of state a for a month so its not like i can run out and snap some lol.

I want to say the notches were 1/8" - 1/4" deep.

I should probably specifiy as well, i made the notches as evenly spaced as possible between the existing slots in the Fluidampr. Basically take a circle and place 4 points evenly spaced around the circumference.
Click to expand...

gotcha, i will try it!
 
IMG_3789[1].jpg

IMG_3790[1].jpg

The autometer diesel tach needs 4 notches ( or pickups) equally spaced to work. my fluidampr had 2 1/2" wide 3/16 deep notches i added 2. I welded a piece of pipe to there relocation bracket and good to go. I think its bull**** for what that tach costs they don't sell any kind of install kit....
 
I had issue like this and changed my pickup Lactions 3 times no fix .. it's was a bad pickup sensor sent the complete tach in with pickup and got tested . And they sent a new pickup no charge .. I put several on that would pickup off notches no issues ..
 
Why not just make a bracket to pick up off the head of the damper bolts?

Even though you only have 2 notches, it still shouldn't be jumping around. It would just be reading 1/2 speed of actual RPM. When they jump around usually the gap is too big. IIRC the gap is supposed to be .030-.050". An old credit card works great for setting the gap as they are usually just a hair over .030". Just make sure your bracket is very secure and won't be affected by vibrations at high RPM.
 
Last edited:
Bluegrassdiesel, Do you have a picture of the bracket to pickup the balancer bolts? I was going to do my that way but couldn't figure out a secure way so it wouldn't vibrate and dance around. Thanks
 
BluegrassDiesel said:
Why not just make a bracket to pick up off the head of the damper bolts?

Even though you only have 2 notches, it still shouldn't be jumping around. It would just be reading 1/2 speed of actual RPM. When they jump around usually the gap is too big. IIRC the gap is supposed to be .030-.050". An old credit card works great for setting the gap as they are usually just a hair over .030". Just make sure your bracket is very secure and won't be affected by vibrations at high RPM.
Click to expand...

I set it at .040 with a feeler gauge. I may just make that bracket like you said.
 
PVXCummins said:
2 things I did to combat any issue of the tach jumping.

First, I took a dremel to my Fluidampr and made 2 additional notches on the same side i had the tach pickup located. I didn't make grooves all the way across the surface of the damper, just 1" x 1" notchs IIRC.

2nd, I stuck the tach wires in a drill and twisted them together. Didn't go to crazy, just enough to get them together. I then wrapped the wires in HVAC tape from the tach pickup all the way to the back of the tach. Then wrapped that in electrical tape. The Aluminum HVAC will help dissipate the engine harmonics that cause the tach to jump in the higher RPMs.

Did that 2+ years ago and have a dozen or so hooks on the truck and havent had any issues with the tach jumping. Its as smooth as factory. Only issue to note would be the tach bouncing once i hit about 5,500 RPM right before i ride the clutch out.
Click to expand...
I took your advice. So far it has worked perfectly up to 3000rpm, just havent taken it any higher yet.
 
BluegrassDiesel said:
Why not just make a bracket to pick up off the head of the damper bolts?

Even though you only have 2 notches, it still shouldn't be jumping around. It would just be reading 1/2 speed of actual RPM. When they jump around usually the gap is too big. IIRC the gap is supposed to be .030-.050". An old credit card works great for setting the gap as they are usually just a hair over .030". Just make sure your bracket is very secure and won't be affected by vibrations at high RPM.
Click to expand...

I have the same setup on mine and it has worked great for years.
 
You must log in or register to reply here.
Back
Top