Transmission slipping?

PamzJoe · #1 06-06-2006, 04:39 PM

Yesterday, went to go when the light went green, but my truck just kind of floundered like I was in soft sand. Maybe the tranny was slipping? Has this happened to anyone else? It's an '05 Z71 ext cab w/the 5.3, auto trans. Any advice will be appreciated.
Joe

wannablast · #2 06-07-2006, 11:50 AM

I have a 2001 Z-71 that will periodically do the same thing. It only does it every now and then. I just rolled over 100K miles and except for the occasional "burp" it still works fine. It started when my truck was fairly new and it may not do it for a year or so. I have never taken it in and ask a service dept about it. ????

wrparks · #3 06-07-2006, 01:44 PM

Mine does it probably about once or twice a year. Just like you said, only from a dead stop, and just acts strange. Sometimes, it feels like I'm going over a string of potholes at about 90 mph. You know, you feel it, but not much. Scares the hell out of you when it happens. The first time it happened was at about 20,000 miles. Got maybe 30 now. No codes are set, and I can't make it do it on command so the dealer just laughs at you. We'll see what happens. Good to hear sombody got 100,000 on one doing this. Mines an 04 WT model.

PamzJoe · #4 06-07-2006, 04:39 PM

I've had one other person tell me theirs did it on ocation also. Glad to hear from you guys, maybe it won't be a major problem.
Joe

kenny-1907 · #5 06-07-2006, 06:13 PM

Most likely what is happening is it is starting out in second gear and there is an update for the programming for the pcm for that very issue. My silverado has done the same thing about 3 times in the three years i have owned it but because it is a 2000 there is no update for it, but there is for '03 and up. I was able to get an update for general driveability issues last summer and it has not done it again yet so hopefully it solved the problem.

PamzJoe · #6 06-07-2006, 11:12 PM

Quote:

Originally Posted by kenny-1907

Most likely what is happening is it is starting out in second gear and there is an update for the programming for the pcm for that very issue. My silverado has done the same thing about 3 times in the three years i have owned it but because it is a 2000 there is no update for it, but there is for '03 and up. I was able to get an update for general driveability issues last summer and it has not done it again yet so hopefully it solved the problem.

I'm not sure what you mean by "update". Is this something I have done at the dealership? BTW It's an '05 Silverado Z71, w/almost 22,000 miles. Thanks, Joe

ChevyLover247 · #7 06-08-2006, 07:20 AM

I have an '04 Silverado that does the same thing periodically. It started about 2 months after I purchased it new. Any advice would be greatly appreciated.

kenny-1907 · #8 06-08-2006, 05:57 PM

For 2003's and up there is a programming update for the pcm (powertrain control module). That is the computer (brain) for the engine timing, fuel curve and all that fun stuff as well as when the trans shifts and what gear it should be it and at what rpm ect. This update is done at the dealership in the service dept and it cost me $60. Basically they hook your trucks computer to another computer and upload new programming into your trucks computer to fix the "bugs" such as starting out in second gear ect. Kinda like updating windows to fix bugs. I am not sure about your 2005 whether it will cost you anything or not but imo it should be done cause starting out in second gear is not really a good thing although it is not that bad either.

kenny-1907 · #9 06-08-2006, 06:00 PM

Quote:

Originally Posted by ChevyLover247

I have an '04 Silverado that does the same thing periodically. It started about 2 months after I purchased it new. Any advice would be greatly appreciated.

Call the service dept at your dealership and tell them exactally what it is doing and that you heard there is a programming update for the pcm that adresses the issue and they should know what you are talking about. Then it is simply a matter of making an appointment to take it in and get the pcm updated which takes about 20-30 mins only.

TexasF355F1 · #10 06-08-2006, 08:55 PM

My trans has hickuped on occasion from day one. It seems to get stuck b/c 2 and 3 typically. Usually when I give it gas and it downshifts into second then immediately tries to hit 3rd then back to 2nd, then finally stays in second and takes off. Did it yesterday as a matter of fact.

twomorestrokes · #11 06-09-2006, 09:52 AM

My '02 4L80E has done it about twice a year also. Always after coming to a short stop like a stop sign and trying to take off again. There is nothing there when pressing the pedal but the engine does not free rev. Acts very strange. Then I let off the gas, sometimes a clunk is felt, and it's fine. Too many electronic controls having to work together is my feeling. Other than that, the fluid stays red and it shifts nice all other times. If the trans was actually slipping it would set a code and trigger the light.

Just another quirk. With all of these quirks, clunks, and rattles, I will probably end up ignoring a serious problem if it arises chalking it up as another "quirk".

wrparks · #12 10-13-2006, 09:53 AM

I hate to pull this thread out of the past, but I finally got around to having my PCM reprogrammed. My warranty was almost over, so I decided I better hurry up if I wanted it to be free. Anyway, I'll probably know in a year or two if the update worked to solve the problem

.

In the meantime, the paperwork I got says J6354 (which I think is GM speak for the type of work done, ie reprogram PCM), then has Reprogramming 249 WS2 FC: 3L

So, does anybody know what else was changed when this was updated? Just curious, because I don't think I noticed anything differnet on the drive home.

silverado122775 · #13 10-13-2006, 10:16 AM

My truck does every once in a while as well.. I first noticed it after the warrenty was gone..LOL. It has not done it in a while.. but you are all correct.. it feels like it is starting in 2nd gear from a dead stop... then shifts down to 1st once you give it more gas.

wrparks · #14 10-13-2006, 11:22 AM

Yea, it sounds like a relatively common problem. It can't be good for the transmission, so I hope it's fixed. I'm not sure about the 2000 models, but it might be worth looking into for you.

wannablast · #15 10-13-2006, 12:24 PM

*update* My transmission BROKE a couple of months ago. (100,250 miles) It seems that there is a weakness in the light duty truck transmissions. I had driven my truck front wheels over a parking lot divider so my boat trailer wouldn't stick too far out in the parking lot. When I tried to back over the hump my transmission just let go. I was able to pull forward and drive out but I had no reverse or 2nd gear. I had to pull my boat for about 100 miles with no 2nd or reverse. I saw the broken part and my rebuilder explained what he did to "beef it up." He said it is a weakness with that transmission and he is a goodwrench mechanic and he sees them all the time. I forgot to mention the "hic-cup" while starting out occasionally but it didn't have anything to do with the transmission breaking.

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