Clark

Hello.

I recently dropped a rebuilt 01 Mustang GT engine into my 01 Mustang GT. (Rebuild has 90k miles, my car has 105k miles.)

Upon installation of the motor, I added BBK Shorty Ceramic Headers. I also added a Bassani catted X-Pipe and a Bassani cat back.

The car sounds great (small exhaust leak right now) but I am having an issue with my transmission.

The car will not shift into the overdrive gear, 4th gear. Also, when I press overdrive off, the car does not shift into a lower gear or do anything for that matter. It is almost as if the overdrive button is not hooked up, and the overdrive gear (4th gear) disappeared.

On top of that, when I have the car in drive, and shift it into reverse, it takes a second for the car to click into reverse. I feel almost as if the X-pipe is choking the shift cable by the transmission.

Any thoughts, opinions, comments, or suggestions, would be greatly appreciated.


Thank you.

Hangwire

Your car doesn't downshift because it isnt in 4TH. All the O/D off button does is tell the ECU that its not allowed to shift into 4th so if you arent there in the first place its not gonna be able to downshift to 3rd. If in 3rd and you need to downshift manually drop it down to 2nd. However be aware you should never downshift from 2-1 manually while moving.

If your overdrive is fubar then you will also see problems with 2nd gear as the OD gear and 2nd gear on this trans(4R70W) share the same servo, so something doesnt add up here if 2nd shifts smooth and works fine yet 4th doesn't even engage.

It is normal for there to be delay in between shifts from neutral to reverse. Its not instant even with a modified transmission.

djd2392

Im just curious..why shouldnt you downshift from 2 to 1 while moving?

Clark

If I am cruising in 3rd gear, and step on it, the car will drop back down into second or first just fine on its own. 2nd gear is completely fine. It is literally like my car does not have a 4th gear. What can spark this problem? I Have not had the chance to top out third gear to see if it will shift into fourth after.

djd2392

Overdrive usually clicks in about 40 under normal driving conditons..what happens when you click the overdrive button? does it indicate that its off and on on your dashboard?

Clark

Absoulutely nothing happens when I click the overdrive button. The light does come on to indicate O/D off. The car uses 3rd gear as what used to be 4th gear.

ZeroTX

My first thought would be something electronic...a connector or something, but I don't know much about transmissions. I do know that it's electronically controlled...

Clark

Now the car is reluctant to shift into 3rd gear at the end of 2nd, or even if i slowly accelerate to about 50, the car likes to stay in 2nd...

ZeroTX

Not sounding good, man. Had a tranny shop drive/look at it? It's usually free to get the estimate.

Clark

Damn... Had the transmission rebuilt a while ago. Got a warranty on it. Hopefully they will cover it if I pulled the engine/tranny myself.