Auto tranny question

black4.6vert

New Member
Mar 15, 2006
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I recently picked up an 03 GT, and I think I may have a tranny problem with it. Most of the time the car seems to shift fine. However, when I'm going slow, say under 30 mph, when I let off the gas the car seems to stutter for just a second. It's like it's downshiftting real hard, although I think I'm in first when it does it. This probably isn't descriptive enough to explain it, but I don't really know how else to describe it, other then that everything seems normal.

Someone tell me I don't need a new tranny at 36k miles.
 
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I knew I was forgetting something, I had the transmission flushed over the weekend, one for good maintenance practices, but I was also hopeing it would fix this shift thing. From your response I'm going to assume that I was right in my assumption that the auto's on the GT don't downshift harder then most other cars.

Any other thoughts?
 
It's not so much that it makes any kind of sound, although a klunk is probably a good way to say it. It's like If I'm barely on the gas, and then I take my foot off the pedal, the car just kinda lurchs for a second. I use this description loosely because the engine sound fine, but it's like the car just hiccups or something and then it's fine. It's not a super hard lurch, but if you weren't expecting it it can catch you off guard a little. The RPM doesn't drop super low or anything as far as I can tell, and it doesn't do it all the time, but often enough.
 
Thanks, I just wanted to hear another owner tell me that before I freaked out about it. That and I didn't want to throw my xcal2 tune with the shift changes in the car and have it destroy my tranny because it's shifting harder.
 
Is a cooler really that vital with just a tune? I ran my old V6 without one for about a year and never had any problems. Also what all's involved in installing a cooler??

Thanks again for all the advice
 
There are some great tech threads on cooler install a search will reveal them.

Even when stock a cooler is highly recommended. When you firm up the shifts with the XCal the cooler becomes even more vital to the longevity of the transmission.

Here is a great site for 4R70W information: www.tccoa.com
 
You want to add a Tranny cooler, that should be the first mod to any 4R70W. By chance, what fluid did you use when you flushed the transmission? You may have used the wrong fluid and that could cause the problem.
 
Mine did the same thing. Superchips programer and 3.73 gears helped reduce it. I just did the J-mod last weekend, and it hasn't done it since.
Here is a great site for 4R70W information: www.tccoa.com. Ther you'll find info on the J-mod. It's a little dated, but excellant info. Just do a search on the J-mod at this forum, and you'll see the positive results. I found a link to a simplified howto for 99 and up Fords but I can't find the link. I'm sure I found it by doing a J-mod search here. Followed those instructions, an love the results. Nice crisp shifts under normal driving, not too hard though, and went snakie at wide open throttle on the 1-2 shift. Perfect!:SNSign:
 
black4.6vert:

I think what you are feeling is the torque converter unlocking. Your tuner can get rid of this annoying feature.

Like the others have recommended, do the J-mod, get a good sized tranny cooler, and keep the fluid changed out every 15k miles.

Chris