4wd fails to engage

Hey guys,

New to TacomaWorld. I have an 09 Tacoma Sport, 6 spd Manual Transmission. The 4wd has always had issues engaging, several months ago on the fly 4wd stopped working. If I stopped the vehicle it would engage. Several weeks ago I began having further issues when I stopped. I could usually get it to engage after banging on the transfer case, cycling the switch, driving in circles etc. After researching the threads here I thought I had found the issue with the ADD on the front diff. Removed the existing and took it apart, no corrosion or bent connectors. I've connected the motor to a battery and can confirm it is functional. The microswitch at terminals 3 & 4 reads 0 ohms when the switch is closed.

I have the truck jacked up with all 4 wheels off the ground. I can confirm the transfer case actuator is engaging, front driveshaft spins when the truck is in gear and 4hi is selected. I have the ADD plugged into the harness but the fork is not moving when the selector is manipulated. Not sure what to check next.

 

You will have more luck in the 2nd gen forum probably.