I’ve searched this and other forums for a couple of days, and haven’t found anything similar. This may be a bit long, but I’m trying to include as much details as I can. I’ve got an ’07 GT, auto, with a JLT intake and a Bama 91 race tune. It’s got 74,000 miles, and maybe a couple of hundred quarter mile passes. Last tranny service was at 30,000 miles. (I know, it’s overdue!)
A few weeks ago, I noticed that in the staging lanes, it took a second or so of cranking to start the car. It was nothing drastic, but usually I would just tap the key and it fired. I told myself that it may be getting to be getting time for a new battery. I ran my two time trials, and noticed that I was maybe a tenth slower than I thought I would be, given the conditions. But times here (5,800 feet) will vary widely with the DA, so I wasn’t too concerned. When I pulled back into the pits after the scond time trial, as I went to back into my space, it hesitated for a second before going into reverse. Again, I wasn’t too concerned, but it had never done that.
After waiting for time trials to finish, and for them to run the other class, I heard the call for my group to go to the staging lanes. I got in the car, fired it up, put it in “D”, and nothing! Tried reverse, no go. The linkage was working, because the car came out of park, and could be pushed, and the reverse lights came on. I tried revving it up, just a little, probably no more than 2000 RPM, and it still wouldn’t go into gear. The RPM didn’t change, at least not perceptively. I was thinking that maybe since the battery was acting up a bit, maybe the PCM was not getting enough voltage, and that could be it. We were also thinking it may be electronic, so we started looking for fuses and relays that might control the tranny, but couldn’t figured it out. I reloaded the stock tune, and tried it. A buddy trailered it home for me.
The next morning, my plan was start it up, try it, check for codes (the O/D light has never flashed in the car), and maybe disconnect the battery for a while. Then, if it still didn’t work, put the stock airbox back on, take it to the dealer, and hope they didn’t look at the aluminum driveshaft and aftermarket LCAs and tell me my extended warranty would not cover this. I started it up, and nothing. I tried to rev it gently like the night before, and nothing. I thought, “what the hell”, and gunned it up to 3500-4000 RPM. BAM! It slammed into gear. I shifted it through gears a couple of times, and drove it around the block. All was well.
I drove it to work the next day, and it was fine. Didn’t seem to be slipping, highway RPM the same as normal, MPG same as always.
The following Friday, I was back at the track. I went through two time trials and two rounds of eliminations. Out of the 4 runs, it did the same thing twice…when backing into the parking space, it would hesitate a second before going into reverse. If it did that, then when I went to drive it again, I would have to gun it up to almost 4000 RPM, and it would slam into gear. After the first time, I thought, well, it could be heat related, so I didn’t do any more burnouts. The second time that it did the hesitation into reverse thing, I immediately shifted it back into “D”, pulled forward a bit, backed back up and pulled forward a couple of times. But after the car had cooled down, and it was time to make my next run, it wouldn’t go into gear until I gunned it.
It has only done this three times, but each time it was after a ¼ mile run. I’ve only driven it twice since then, and it is shifting fine; although it might be my imagination, it felt like I had to give it a little more gas than usual to back up my driveway last time.
Plans are to put it back to stock, and go get the tranny flushed and filled, but the track is now closed for the season, so I won’t even know if that did anything until next spring.
I’m wondering, though, could it just be that my fluid is low? I’ve never noticed any fluid under the car, and the last time I looked at it, the tranny was dry, so I don’t think I lost a bunch out of the vent or anything. Everything I’ve read about failures on the 5R55S’s seems to include slipping, or losing a gear. Once I do get it to go into gear, it shifts fine, and still has no problem barking the tires when you kick it into passing gear from 40 mph or so. I’m stumped.
A few weeks ago, I noticed that in the staging lanes, it took a second or so of cranking to start the car. It was nothing drastic, but usually I would just tap the key and it fired. I told myself that it may be getting to be getting time for a new battery. I ran my two time trials, and noticed that I was maybe a tenth slower than I thought I would be, given the conditions. But times here (5,800 feet) will vary widely with the DA, so I wasn’t too concerned. When I pulled back into the pits after the scond time trial, as I went to back into my space, it hesitated for a second before going into reverse. Again, I wasn’t too concerned, but it had never done that.
After waiting for time trials to finish, and for them to run the other class, I heard the call for my group to go to the staging lanes. I got in the car, fired it up, put it in “D”, and nothing! Tried reverse, no go. The linkage was working, because the car came out of park, and could be pushed, and the reverse lights came on. I tried revving it up, just a little, probably no more than 2000 RPM, and it still wouldn’t go into gear. The RPM didn’t change, at least not perceptively. I was thinking that maybe since the battery was acting up a bit, maybe the PCM was not getting enough voltage, and that could be it. We were also thinking it may be electronic, so we started looking for fuses and relays that might control the tranny, but couldn’t figured it out. I reloaded the stock tune, and tried it. A buddy trailered it home for me.
The next morning, my plan was start it up, try it, check for codes (the O/D light has never flashed in the car), and maybe disconnect the battery for a while. Then, if it still didn’t work, put the stock airbox back on, take it to the dealer, and hope they didn’t look at the aluminum driveshaft and aftermarket LCAs and tell me my extended warranty would not cover this. I started it up, and nothing. I tried to rev it gently like the night before, and nothing. I thought, “what the hell”, and gunned it up to 3500-4000 RPM. BAM! It slammed into gear. I shifted it through gears a couple of times, and drove it around the block. All was well.
I drove it to work the next day, and it was fine. Didn’t seem to be slipping, highway RPM the same as normal, MPG same as always.
The following Friday, I was back at the track. I went through two time trials and two rounds of eliminations. Out of the 4 runs, it did the same thing twice…when backing into the parking space, it would hesitate a second before going into reverse. If it did that, then when I went to drive it again, I would have to gun it up to almost 4000 RPM, and it would slam into gear. After the first time, I thought, well, it could be heat related, so I didn’t do any more burnouts. The second time that it did the hesitation into reverse thing, I immediately shifted it back into “D”, pulled forward a bit, backed back up and pulled forward a couple of times. But after the car had cooled down, and it was time to make my next run, it wouldn’t go into gear until I gunned it.
It has only done this three times, but each time it was after a ¼ mile run. I’ve only driven it twice since then, and it is shifting fine; although it might be my imagination, it felt like I had to give it a little more gas than usual to back up my driveway last time.
Plans are to put it back to stock, and go get the tranny flushed and filled, but the track is now closed for the season, so I won’t even know if that did anything until next spring.
I’m wondering, though, could it just be that my fluid is low? I’ve never noticed any fluid under the car, and the last time I looked at it, the tranny was dry, so I don’t think I lost a bunch out of the vent or anything. Everything I’ve read about failures on the 5R55S’s seems to include slipping, or losing a gear. Once I do get it to go into gear, it shifts fine, and still has no problem barking the tires when you kick it into passing gear from 40 mph or so. I’m stumped.
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