Speedometor / Ma70 Gear ratio

cre · 08-24-2010, 04:14 AM

If the speedometer is off but all the gearing is right you can recalibrate the gauge. There is an arm behind the face which adjusts it my percentage and flat out moving the needle is what you'll do fix a constant offset (ie: it's ALWAYS 5 MPH low).

If the gearing does NOT match you may swap out the speedometer driven gear or worst case swap out the diff to make everything right.

You may recalibrate the gauge to make the speed report accurately without changing any gearing (diff or speedo drive gear) BUT the odometer will still be off.

When changing to a different diff the proper course of action is to change the speedometer drive gear for one the appropriate size or to install small gear box which changes rate at which the speedometer cable spins (there are actually shops that do just this).

EDIT: Here's a picture showing the adjustment arm which you may use to calibrate a speedometer which is off by a percentage (ie, you're doing 30 but it reports 33 and then when doing 60 it reports 66).

08-24-2010, 04:14 AM	#5
cre Toyota Racing Development Join Date: Apr 2007 Posts: 5,038	If the speedometer is off but all the gearing is right you can recalibrate the gauge. There is an arm behind the face which adjusts it my percentage and flat out moving the needle is what you'll do fix a constant offset (ie: it's ALWAYS 5 MPH low). If the gearing does NOT match you may swap out the speedometer driven gear or worst case swap out the diff to make everything right. You may recalibrate the gauge to make the speed report accurately without changing any gearing (diff or speedo drive gear) BUT the odometer will still be off. When changing to a different diff the proper course of action is to change the speedometer drive gear for one the appropriate size or to install small gear box which changes rate at which the speedometer cable spins (there are actually shops that do just this). EDIT: Here's a picture showing the adjustment arm which you may use to calibrate a speedometer which is off by a percentage (ie, you're doing 30 but it reports 33 and then when doing 60 it reports 66). __________________ If something breaks or you need to contact a member of the administration please post HERE. Unless it's a private or administration matter please post it on the forum. It benefits no one else if car related questions aren't posted for future users and takes away from the time I'm able to spend helping on the rest of the forum. If you're so inclined I'm always more than happy to accept tips via PayPal. Tip Jar ---> Last edited by cre; 03-11-2012 at 03:55 AM.