VSS Speed Sensor

[iamfastrr]

I am going to be wiring up my EFI and Baumann Optishift for the 4R70W. I plan on running a electronic speedometer.

Do I need to use the VSS on the transfer case or can I pull the speed off of the transmission for the speedometer and EFI computer?

Thanks

 

[kc15842]

I am going to be wiring up my EFI and Baumann Optishift for the 4R70W. I plan on running a electronic speedometer.

Do I need to use the VSS on the transfer case or can I pull the speed off of the transmission for the speedometer and EFI computer?

Thanks

Use the VSS off of the TC, I think all of the speed output is from the VSS only. I have a basic AOD so I may not be the best source. I use the VSS for the computer and the cable for the speedo. Please post how you like the 4R70W. I have one complaint of my AOD the calibration of the VB is a bit off , it shifts early unless you put your foot into it. Besides that it is great to have OD, 70 MPH at about 2100 RPM, much better than the C4. Good luck

 

[iamfastrr]

From what I have been able to gather is that the 4R70W has a transmission speed sensor output. I wan't sure if i can use this to replace the VSS.

 

[englewoodcowboy]

I may be wrong but I believe you can adjust your shift points in the AOD by adjusting your kickdown a little.... I wil be instaling an AOD in my EB. Many other sites say the weak link is the lock up torque converter. I know you can help that by reprogramming (via a shift kit) to make it only lock up in OD and also increase the lock up preassure as well to eliminate slipping. I want to build a mild 302, somewhere in the neighborhood of 300 - 350 HP at the crank and may upgrade to the wide ratio kit (4r70w) when I rebuild my tranny o install the AA. Any thoughts or advise?

 

[Broncobowsher]

The 4R70W does have an output shaft speed sensor. I have used it as a VSS for cruise control before. It has a much higher (~3x) pulse count then a VSS, but depending on the speedometer it could probably be programmed to accept it.

But you don't want to use it. The speedometer and odometer will be wrong with in low range. Since you are reading the transmission output shaft speed and adding more gear between that and the ground (low range) will spin the shaft faster for a given speed.