2nd Gen Non-Engine/Transmission tach issues

[Shadrach]

The tach in my buddies 97 seems to be out. Mathematically he should be around 2100 at 110 km or 70 mph but it is reading around 2500+. Any ideas?
David

 

[Bob4x4]

The trans does go into overdrive correctly and no slipping??

 

[Shadrach]

It's a stick.

 

[Bob4x4]

Have you connected a scanner to see if the PCM rpm is accurate?

 

[klcammie]

On my 01 I had to change the cam sensor, just below the vp. I'm not sure if that would help your 97.

 

[GAmes]

If he has 4.10 gears and stock tire size (215/85) that would be about right. With the lower OD ratio of the G56 (compared to my NV4500), and 3.5 rear, my RPM at 70 is about 2300.