treyota

I lifted my '84 3" and put 33" tires on it, and I got a ticket last night. My speedometer is obviously off. I think I'm about 10 m.p.h. off. Meaning I need to lower the speedometer. Anything out there I can just swap over?

waskillywabbit

iTrader: (-1)

Go 10 mph slower.
GPS will help you know how much it's off or just drive beside someone checking their speedo that's correct.
I don't think there's an easy way to recalibrate your speedo.

:wabbit2:

treyota

What about changing gear ratios in the speedometer gear set? If I raise the gears it should lower the speed... Or is it the other way...?

JonnyBoy

You've probably got 4.10's, so at 55 mph on the speedo you're doing roughly 65 mph, 65 on the speedo is roughly 77. I don't know of any different tooth count gears for the transfer case to correct the speedo. There's always the option of changing the gears in the thirds.

Jmitchell5

So if u put bigger tires on are u going faster or slower than ur speedo

Tofer

regear

corax

lower gears + stock tires = speedometer reads faster than actual speed
bigger tires + stock gears = speedometer reads slower than actual speed

toyotabull

They have a speedometer reduction piece that goes between the transmission and the speedometer cable just for that. Where, and if they make it for a toyota, I don't know. But its something to look into. And here it is https://www.yotatech.com/forums/f116...l-pics-195986/

treyota

Thanks Bull, that was really helpful. I called Commercial Speedometer, they're sending my reduction box tomorrow.

toyotabull

Let me know how it turns out. I might have to get one also after I put the rebuilt motor in next weekend. I have been running 36's and 33's for 7 years now and its always been off, lol.

treyota

Got it taken care of. The guys down at Commercial Speedo in Sacramento were knowledgeable and very helpful. I recommend them to anyone having a speedometer issue. Thanks for all you help guys!

89truck3point4

have any idea what they did to fix it? i thought it was cable driven so you cant adjust it

treyota

For about $88.58 they built me a gear reduction box. It's about 3" x 2" and goes in line to the speedo cable. https://www.yotatech.com/forums/f116...l-pics-195986/