BlackMage

o originally bought the speedo gears and had problems with em, then i bought the speedcal and its worked perfect since day 1. i would just spend the money on the speed cal, then if you ever do tires again, do a gear change, you will be able to just jump into the speedcal, change everything up, and be done with it.

swarthyfellow

Yeah that speedcal would be nice except for the fact that i'm in college and i don't have a job... and that kinda puts a damper on well everything. I just want it to be close enough for now.

stangalator

I had a situation like this a few months ago, I went from 2.73's to 4.10's and even with the 23tooth non-ford gear it was 17.4% too high on the speedo. I wanted a 6 tooth drive ear to replace my 8 tooth one and then i could use a 20 tooth speedo ford black gear and it would be +1% off which is basically right on. Only issue was that ford only makes the 6 tooth for the t5 and the 7 tooth is discontinued. I bought the 6 tooth not knowing the fitment issue and i took the transmission apart and noticed the different spline diameter. I ended up grinding the inside of the splines on the gear down to make it fit on the t45. It fit real tight and its been in there with no issues at all and it reads right on the money using a gps to test.

Would i recommend this option... maybe not. I had to remove a bit of material to make it fit. However it is the same gear, just a different spline pattern for a different transmission. I just didn't want to buy the 100 dollar speedo correction gizmo.

swarthyfellow

So what is it basically the same deal with the 4r70w. The drive gear is on transmission that you have to change? Thanks...