Topic: Speedo Calibration

[SpencerS]

Hey guys,

Do i have to get a OBD1 capable code reader to calibrate the speedo for a 89 toyota pickup? Or should i take it to the shop and have them just do it?

Rig: 89 Toyota Pickup, 22re, 35x12.50xr15, 5.29:1, Dual Cases 4.7

Thanks guys!

[emsvitil]

89 may be mechanical..............(86 is)

In which case you'll have to change the gear in the tranny (or regear the differentials (or get different diameter tires))

[Snowtoy]

It is a mechanical speedo, IIRC Toyota made the switch in '92 or '93 to electric.

However, w/the 35's and 5.29's the speedometer isn't likely off enough to warrant a recalibration.  The difference between the lower 5.29's gears and the 35's is only 4%.  This would make the speedo read high by 4%, i.e., when reading 50mph, your speed would be about 48, if the speedometer was reading correctly to begin with.

[SpencerS [OP]]

Yea it must have been way off before because its about 13 mph off so im going 57 and yhe speedo reads 70

[emsvitil]

Pull the speedo gear out of the transfer case (some oil will drip) and count the teeth.........

[SpencerS [OP]]

I will prolly just end up buying a garmin or cheapie gps for speedo reasons. Ill tear into it once i have the time and money. Thanks guys

[4LoRunner]

with my 4runner 22re-t 35x12.5 4.88 duals stock gears i run pass those police radar things on the side of the road it says its dead on but with my gps it says 2-3 mph so what do i trust?

[Snowtoy]

The GPS speed is the correct speed, those roadside side radar boxes are an approximate speed.  Radar devices like the guns and the road side boxes have to be re-calibrated every so often to keep them accurate, and they usually aren't.  2-3 mph difference isn't going to get you a ticket, it usually requires 10mph above the speed limit before you are going to get cited.