47re Trans not shifting to second gear

[91shelbydaytona]

Driving down the road the truck will hold first for a long time and then eventually when it tries to shift to second it goes to neutral (not moving) state. pressure checks shows 0 psi to front servo, 0 psi gov pressure up to 10-15 mph, 90 psi line at idle, but will only make 95 psi wiring open throttle valve. Fluid level is full. We went through valvebody and installed transgo kit but didnt notice anything out of ordinary. Also replaced the gov solenoid with the gm conversion piece, replaced front servo/ accumulator with sonnax pieces, hd band strut and wedge while we were in there. Anyone else ran into an issue like this?

 

[01silver bullet]

Did you adjust the band correctly when done!?

 

[91shelbydaytona]

Did you adjust the band correctly when done!?

Yes which is unrelated because there is 0 psi to front servo which applies the band. Its a pressure issue somewhere

 

[fox]

Ground speed sensor on the od section.

 

[91shelbydaytona]

Ground speed sensor on the od section.

your saying create a new ground for the od speed sensor?

 

[fox]

NO!!!
The speed sensor is suspect.
They can be bought for $15--17.
It can still be the two sensors on the VB but do this sensor first.

 

[mathews8pt]

Yea try the speed sensor first! Cheap and easy to try

 

[91shelbydaytona]

Finally got the owner to replace it. Speed sensor fixed it. Thanks everyone, learn something new everytime I log on lol