Tachometer
 

My tachometer reads approximately 48% high based upon the AC display verification.

Re: Tachometer
 

Likely a '90 and it's not unusual and will likely continue to get worse. There's DIY repairs for recalibration and I'm sure someone will provide some links and maybe personal experiences. I understand the requirements but have never personally done a fix.

I discovered mine when actually trying to confirm a rear axle ratio that would have explained my tach variance but this was on a car that wasn't thought to be modified. I checked mine vs. a Tech1 scanner rather than the C68 display. Mine is repaired and correct but NOT by me.

Re: Tachometer
 

Easy way ? Take the lens off then gently pull the sweep off . Then read set it and push the sweep back on.

Re: Tachometer
 

Not sure what you mean by pulling the sweep.

Re: Tachometer
 

OK, I am guessing by "sweep" you are referring to the tach needle?

Re: Tachometer
 

Re: Tachometer
 

Sweep = Tach needle.

Re: Tachometer
 

He's kidding ;)!!

The error is a % (of rpm) error. In short, re-positioning the needle to read accurately only works at one rpm value. the same % error will result above or below that "set" rpm.

Re: Tachometer
 

One way to get higher revving LT5!

Re: Tachometer
 

Yea. Who knew these LT5's would get up to 8,000 RPMs without hitting the rev limiter.