BiohazardDeath

So a few months ago my Mustang, on cold starts, would not shift into drive. It would shift into every gear and work fine but I had to go from Park to Drive a couple times before it engaged. I didn't worry too much about it because it's not a daily driver anymore. Now it refused to go into Drive. Over the past two weeks every time I drive it, it will not shift into drive, cold or hot start, unless I go down to 1st and back to Drive. Park works, Reverse works, gears 1-3 work. But Drive will not engage unless I go from 1st to Drive. After that, it runs perfectly fine and drive like nothing is wrong. No Check Engine Lights either. Any help would greatly be appreciated, thanks! Below are the specs to the car.

-2005 Mustang GT
-150k miles
-New Automatic Transmission from a 2006 Mustang GT put in at 90k miles, fluid changed 10k miles ago (2 years roughly)
-Will not shift into drive unless I put it into 1st gear first then back to drive, after that it drives fine, all other gears work
-No CEL showing



Thank you!

algregory

I don't really have a clue to be honest. However, I as told many years ago that automatic transmissions now work by "valves" in it, versus the old "bands" thing.

So, I be thinking that your linkage is the issue. Check it over for tightness, movement, bushings, what have you. FWIW

Derf00

Automatics have almost always worked with 'Valves' thus the part, Valve body. They also still have bands in many of them. The exception being the DSG (dual synchro gear) type from the German auto makers and the like.

The difference was Manual valve body vs solenoid/automatic valve bodies. Almost all automatics (that I'm aware of) now have solenoids in them to control the valve body including the DSG transmissions.

Anyways, yes, check the linkage. On the side of the transmission is a Transmission Range Sensor it tells the transmission what position the shifter is in. If this is kinked or loose, you'll have issues with selecting the correct gear.

The sensor is mechanical and electronic so even if the linkage looks fine, the sensor can still be bad. You'd have to find a pin-out schematic online to find out how to test it. If that's not it, it[s most like the valve body or a solenoid that's failing.