FJ40 Early Gauge Adjustment/Calibration

[JVZii]

I hope this is helpful post for all of you pre 1972 FJ40 owners. I looked all around for this on mud and did not see anything about it.

Have you every looked at your cluster and wondered "where the needle for my oil pressure gauge" or is your fuel gauge always at 1/4 tank even when the key is off? Have you looked inside the little hole on the front of the gauge and thought "maybe if I stick a screwdriver in there I can bend something to get the needle where it should be" only to hate yourself a few minutes later (ask me how I know.)

There is a way to adjust the needles. If you pull the cluster and remove the gauge from the housing, on the back of the gauge there is a small hole with a few teeth at the top, those teeth can be moved back and forth to set the resting position of the needle higher or lower on the gauge. I am not sure if this qualifiers as an adjustment or calibration but it is nice to have all of your gauges start from the same position each morning when you start your 40 up.

I removed the gauge face on this gauge to show how the gauge mechanism swings on the upper rivet.

Put a screw driver into the lower hole and push the teeth to the left or right to get the needle to the resting position that you want.

Once you are done you can rest assured that your gauges still won't work all that well but at least they look pretty in the pictures.

Jack

 

[Engineer8000]

zero and span adjustments?

 

[JVZii]

zero and span adjustments?

I bet that is what the other adjustment is. I am going to try to peg one of the gauges and see if I can adjust the upper limit with the other arm of the gauge.

 

[franklin40]

thanks for this info. after making sure my engine temp was correct with a temp gun at the thermostat i made this adjustment for my temp gauge. it really doesn’t take much. i over did it the first time and at operating temp it was only at the far left bar. readjusted it and it now sits just below half at operating temp. better than being pegged all the way right!! this is where i had it set the first time

then after adjusting it again it now sits here with no power

and then when it’s warm with power

 

[Bear]

Thanks for the education @JVZii !

 

[red66toy]

Super info! Awesome tech @JVZii

 

[Roastchestnuts]

Old thread, but I am wondering if this is whats up with my gage. Like somebody went in and messed with it or it needs to be calibrated It reads right on the right tick mark when at temp. The only gage I actually trust in my gage cluster is the fuel gage haha.

 

[JVZii]

Old thread, but I am wondering if this is whats up with my gage. Like somebody went in and messed with it or it needs to be calibrated It reads right on the right tick mark when at temp. The only gage I actually trust in my gage cluster is the fuel gage haha.

Tue old style temp gauges have this happen. They work opposite the others. You can adjust them using this method but make sure your gauge has good contact with the sending unit first. You can usually tell by grounding out the wire to the sending unit for a few seconds.

If it starts going to cool right away then it may be sending unit.

 

[Roastchestnuts]

Tue old style temp gauges have this happen. They work opposite the others. You can adjust them using this method but make sure your gauge has good contact with the sending unit first. You can usually tell by grounding out the wire to the sending unit for a few seconds.

If it starts going to cool right away then it may be sending unit.

I just did a swap to a 2f engine from a sbc. its a new early type sending unit and with the proper 1f tube for the sensor. I think everything is working correctly its just off a little. the only other thing I could think off is maybe the jiggle valve is clocked weird in the tstat. seems to be opening and closing though.