[pavanbabut]

Originally Posted by svxfiles

Gentlemen,
The speedometer sensor is driven by a gear on the passenger side of the front differential.
The amount of rotations of the gear is determined by the tire diameter, and the coefficent of friction, of the tire, controling the amount of rotations, of the axles, in relationship to the ring gear.
THE INTERNAL GEAR RATIOS HAVE NOTHING TO DO WITH THE SPEEDOMETER ACCURACY!
It is only the sensor accuracy, the speedometer accuracy, the wireing, tire diameter, and the ability of the splined shafts to transfer power, that can show inaccuracies!
That said, I would "be really interested" in joeaxial's new transmission # on the bell housing, by the starter.
If the trans came from a 1996 2.5 Legacy, then it should be a 4.44 ratio trans, and his 72 mph at 3000 rpm is correct.
If the trans is a 4.111, and the rpm is 3000 at 72, rather than 77 mph, there is some problem, like its not locking up the torque converter?

Think about this, in first, second, third and forth, the speedometer reads the speed of the car, without reguard to the gears inside the transmission unit.
The reason for this is, it only reads the speed/rotations of the front ring gear.

All cars to some degree have a speedometer error.
The internal ratios are not a factor. Tom

Yep!.. i too agree with your statement, that transmission has nothing to do with speedometer reading. But what we are not able to understand is, why this inaccuracy is showing up in such a noticeable level only when we are swapping the trannies of different ratios other than the stock ratio. Afterall we are using the same stock sensor, if our stock one reads 4mph less as someone above stated, why is it now reading more than 7mph (i mean in percentage increase) when we are using the same sensor, same tires and all that is going to change is transmission. I hope now you got what we are worrying about. In my case it doeasnt matter for me untill I am able to make my speedo show me atleast or approximate to accurate reading.

-Pavan.