Changing cluster - is my odometer going to be correct?

[Ecky]

^ As topic states, I'm replacing the cluster in my Del Sol and was wondering what's going to be affected. My car is the VTEC trim and came with 195/60R14 tires. My new cluster is out of the Si trim, which had 185/60R14 tires. My question is, will the odometer and speedometer read incorrectly? The new cluster is out of a car that has 2% more revs/mile.

How does the odometer work? Do I need to keep my old one, will the new one read too fast? I can tell the speedometer's reading appears to be determined by a small motor and spring, is the spring going to be different in the two speedometers because they're for different wheel sizes? Or is that determined elsewhere?

[gone-ot]

...short answer: probably not. If it uses mechanical speedometer drive shaft, a simple (gear adapter) can usually solve the problem. If it's an electronic speedometer, you MIGHT be able to have the dealership "re-program" the electronics to solve the problem.

[Fat Charlie]

You're only going to be 2% off. When you think you're going 50mph you're really only going to be doing 49. For every 1000 miles you go, your car is going to report 1020 miles.

My tires are larger than stock, so I'm 3.4% the other way. The Subaru store says that they can't flash the cluster, so all I do is multiply the odometer by 1.034 when I fill up. Other than that, I wouldn't worry about it.

[ajjct]

if you keep your old speedometer your real mileage reading will show your real mlieage of your car but may be off a little. now with your new speedometer will show the mileage out of the car you got it from. lets say yuor old one was 123000 and the new one is 86000. when i changed mine so i had a tack, i put my old speedometer into it so i know that the car really had on it and im up to 296000 plus.

[Ecky]

After doing a lot of reading... I'm lead to believe that ALL Hondas (of that era anyway) put out very close to 8208 pulses per mile from the VSS. Since they have different tire sizes (and thus different mainshaft rpms per mph), this suggests to me that the adjustment for tire size is done on the other side of the VSS, maybe via a small gear in the transmission case?

Would changing the tranny cause the speedometer to read wrong?

Originally Posted by ajjct

if you keep your old speedometer your real mileage reading will show your real mlieage of your car but may be off a little. now with your new speedometer will show the mileage out of the car you got it from. lets say yuor old one was 123000 and the new one is 86000. when i changed mine so i had a tack, i put my old speedometer into it so i know that the car really had on it and im up to 296000 plus.

I pulled the new odometer apart and rolled the counter around to the correct mileage... but I'm not sure if I should use the old speedometer/odometer in the new cluster, the new speedometer/odometer in the new cluster, or if it doesn't make any difference? I assumed there would be a difference since the trims would have different tire sizes but maybe Honda corrected for that somewhere else.

[ajjct]

if the only thing is the trim package and the years are the same, it should inter change. the years that i can changes parts with spans 4 years but the clusters were only 2 years. (1988/1991--1988/1989). and if you rolled it already just put the new one back together and use it. and why are you changeing it any way. i did mine to have a tack

[Ecky]

Someone hooked up the ground and live to the battery backward and it partially melted my old one. It still works, but it smells like smoke and the back of it looks pretty hideous, and the replacement was cheap.