calibrate RPM guage

[99v6mustang]

Hey i just bought an 02 V6 mustang. the guy that had it before me took out the original guage cluster and put in the look alike cobra guages for the V6. however when he did this he said he had to take out the needles. so supposedly im only pushing 1300 RPMs while doing 60 ,haha. but while doing so ihe messed up the needle fo the RPMs. Everything else is correct, fuel, MPH, bat., and Oil.

My question. Is there a website or can someone type out a step-by-step walk through on how to take out eh guage cluster and reset the RPMs so that they are correct... Thansks

 

[slowfashow]

i have an 04 v-6, when im going around 75 MPH the RPM needle reads around 2500 RPM's in 5th gear, if i go 60 MPH it reads in the 1300 to 1500 rpm area in 5th gear as well, the only thing i can think of that you would have to resynchronize your rpms for is if you installed different size gears and all it takes to do that is a Tuning Chip like the Predator. besides that i dont think its abnormal for your RPM neddle to be like that. What gear are you rolling in when that happens?

 

[99v6mustang]

Im in 5th gear doing 55-60 when its reading 1300's. (BTW my idle is at 500, doesnt sound like that though. sounds higher. maybe around 700 or 800) . As far as i know they are stock gears. Any suggestions on chips? I was looking at the SCT.

 

[Skymarshal]

I wouldn't try fixing this with a tuner. The problem is that the needle was not put back on the shaft correctly. I'm not sure if it's indexed- you might just have to experiment, using an external tach to see if it's in the right place. You could probably get pretty close on the first try if you note where the needle reads vs. the actual RPM and move the needle the precise angle needed (keep the shaft stationary with a tweezers or small needle-nose pliers.

 

[99v6mustang]

Any ideas on the external tach? or should i buy one? Or could i find a computer to read the engines RPM's?
I did another 'test' im at 2000RPM at 75 MPH.

 

[Skymarshal]

I have a needle-style tach that is used for giving older cars tune-ups. I think I paid $20 for it. It only reads up to about 2000 RPM (it's used for setting idle speed), but that's all you need to calibrate the needle to the actual RPM. It sounds like you're not too far off- I think I'm at about 2300 RPM at 75.

 

[99v6mustang]

Alright cool, could i pick on of these up at a local auto parts store?
And one more question, what size is your read end? Im not 100% sure but i think stocks are 2.73 and i do believe that what i have.

 

[Skymarshal]

That kind of tach is called a tach/dwell meter. I'm sure your local auto store has them, or they're online starting at around $5. They look like an analog voltmeter with several scales under the needle (one is RPM).

Your RPM is 1300 at 60 and 2000 at 75? That doesn't seem right. I wonder if the needle is loose and moving around. For reference, I checked today and I'm exactly a needle width above 2000 RPM at exactly 70MPH.

Your diff has 3.27 gears from the factory.

 

[99v6mustang]

Okay, thanks Ill go and look for that tach.

With it being loose maybe, could that be as simple as poping off the panel and pushing the needle on better or would i have to take everything out and then put it all back together?

okay 3.27 thanks.. couldnt find it anywhere.