Speedometer off only at low speeds

[Lostinmormonland]

Hello all! I bought a 2002 Jeep Cherokee X Franken Jeep a few months back and when it came to me the speedometer was off. Fast forward and I have found out the rear gearing is 3.56 and I have a 34 tooth in there. Also it has 31's on 15's that are new so they're more like 30-30.5. At 45mph it's spot on below that it's off by five. With that said no it isn't a Canadian gauge cluster. It was purchased in New York where it sat for 12 years and then went to Texas for 7 years and then came to Utah. I've reset the speedometer and still nothing. Anything helps and is much appreciated

 

[lBasket]

I thought the 3.55 was a 97 only offering

 

[Lostinmormonland]

I thought the 3.55 was a 97 only offering

As stated it's a Franken jeep

 

[TheBoogieman]

I thought the 3.55 was a 97 only offering

You are correct.

 

[Chris]

Hello all! I bought a 2002 Jeep Cherokee X Franken Jeep a few months back and when it came to me the speedometer was off. Fast forward and I have found out the rear gearing is 3.56 and I have a 34 tooth in there. At 45mph it's spot on below that it's off by five. With that said no it isn't a Canadian gauge cluster. It was purchased in New York where it sat for 12 years and then went to Texas for 7 years and then came to Utah. I've reset the speedometer and still nothing. Anything helps and is much appreciated

Is that the correct tooth count for 3.55 gears and whatever tire size you have?

 

[Lostinmormonland]

Is that the correct tooth count for 3.55 gears and whatever tire size you have?

I'm almost certain it is. It had a 29 tooth in it and that was off by 10 @ 60mph. I did the math and came up with needing at 34 tooth

 

[Chris]

I'm almost certain it is. It had a 29 tooth in it and that was off by 10 @ 60mph. I did the math and came up with needing at 34 tooth

What size tires?

 

[Lostinmormonland]

What size tires?

Brand new 31s so more like 30.5

 

[BlueC]

I'm almost certain it is. It had a 29 tooth in it and that was off by 10 @ 60mph. I did the math and came up with needing at 34 tooth

According to your posted chart you need a 31.

 

[Chris]

According to your posted chart you need a 31.

View attachment 665179

Bingo!

 

[TheBoogieman]

 

[Lostinmormonland]

According to your posted chart you need a 31.

View attachment 665179

Would that solve the issue I'm have then? Up until 45mph it's off by 5. After 45 its spot on

 

[Lostinmormonland]

And this one says 32

 

[Lostinmormonland]

View attachment 665183

And this one says 32

 

[KennethS]

Would that solve the issue I'm have then? Up until 45mph it's off by 5. After 45 its spot on

I don't see how that is possible as it should be off by a percentage, which means the faster the vehicle speed, the further off the speedometer reading would be.

 

[Lostinmormonland]

I don't see how that is possible as it should be off by a percentage, which means the faster the vehicle speed, the further off the speedometer reading would be.

When it had the 29 tooth in it, it was off by 10 all around. I did the calculation and that's how I got to the 34 toot