jimkr

This is my first post on these forums, hopefully it won't be too long. I'll start by saying that I'm "old school". I always believed that unless there is a problem with an automatic trans, leave it alone. However, since my 2010 GT is still covered by warranty, I should follow the service recommendations. When I first got the car, with 33,000 miles on it, I wanted to see what it could do. I buried the accelerator and was very impressed at how easily it broke the tires loose going into second gear from a 40mph rolling start. A couple of weeks ago, I had my local trusty repair shop do a trans service. They drained the trans case, and replaced the filter, and filled the case with new fluid, they did not do a complete flush. The car runs great, and the shifts seem a little more "robust", however now when dropping into first at 40, and going into second gear, I no longer get that nice little "chirp". What gives? Anyone have any ideas? Thanks in advance for your responses.

2005Redfire6

Ummm the chirp would be coming from an abrupt shift rather than a smooth shift, my guess is the service on it made it shift smoother!

jimkr

Well, who wants smoother shifts, especially in sport mode? Lol. Problem with smoother shifting= more heat. I've been reading a lot about the 5r55's known issues, and it has me concerned. That's why I had the service done in the first place. I'm not abusing the car in any way, but I do like to "get on it" every now and then and stretch it's legs. I do have a Bama tune, and an Airaid CAI. But that's probably the only mods that I'll be doing.

Nuke

The '10 GT's PCM has the Bullitt tune (which gives you that added 15 crank HP over the 05 thru 09) but likely maintains the Adaptive Learning that the 05 thru 09 have. Granny driving or even frequent city stop and go can "learn" poor performance. Try disconnecting the battery for about 30 minutes to reset the Adaptive Learning. Also, if you chirped in cooler weather, then the Adaptive Learning coupled with softer rubber from the warmer ambient temp now is likely enough sapping to be degrading your power to chirp. These engines heat soak like a *****...

jimkr

Thanks for the input! I was thinking along the same lines, weather, full tank, weight, type of pavement. There is another possibility as well, no actual "chirp" sound. When the trans does the shift it feels quite strong, but at the same time you can feel a bit of a "roughness" from the back end. Sounds weird, but the car really jumps when upshifting, so I can't imagine the tranny is slipping. Maybe the tires just aren't making noise. I'm running Goodyear eagle rs a2 on 19 inch rims. Don't know if they a soft compound tire or not. I think I should just stop worrying about it and just enjoy the car! Lol. Most of my driving is highway. In the city I drive in sport mode, with OD off. I may just do a reset on the adaptive learning over the weekend to be sure. Thanks again for your thoughts!

gregthomas07gt

I had an 06 with an auto that I had flushed at the dealer and they shorted me a quart of fluid. I noticed it because on a steep incline it would come out of gear until I hit level ground. I pulled the middle plug on the 2 piece drain and got no fluid with it running. Shut it off and got a few drops out. Started it up and pumped some fluid in with it running in park until it started running out the plug and all was ok after that. Are you sure they put enough fluid back in?

jimkr

That's an excellent point! Never gave it much thought. I just take it for granted that the job is done right, but as we all know, mistakes happen. It's times like this I wish the darned thing had a dipstick! I should check the fluid level first, then reset the computer, thanks good call. Funny if it turns out to be that simple!