2007 Lt1/5.3/3.73

I own a 2007 Siverado with the 5.3 v8 and the 3.73 rear gear, I' ve noticed a clunking or single knock in what sounds like the transmission when I come to a fairly quick stop, its a intermitton problem, which I am sure the dealer would not take serious! has anyone experianced tranny noise at all? Im wandering if I should extend my warrenty just in case?

Fireguy8

Good discussion at GM-Trucks.com on the same subject

tonzmn

I had the same exact problem on my '07 Silverado LTZ. I took it to the dealer and they said there's a bulletin out on it and they fixed it - no charge. He said the torque on the rear end needs tightening or adjusting. When I picked it up, the service writer said the mechanic told him mine was the worst he had seen. After driving it for 3 days, I've only noticed one time when it clunked very little after stopping at a stop sign. I'm optimistic it has been fixed! They were truthful with me and said it may happen a little and there's not much of a chance it will go away completely. I love this truck so much, if it stays like it is now I'll be fine with it.

2007 Lt1/5.3/3.73

Thanks so much for the reply, I hope my dealer will be as cooperative, You said the torque on the rear end needed tighting or adjusting, by that do you mean the differential? (pumpkin), I dont want to go to the dealer asking them to torque my rear end, lol. By the way I had my truck in for service late this fall for a leaky windsheild and asked them to take care of any service bulitons that may be out, they said there wasnt any, yeah right! anyway if you can be a little more specific I would greatly apprecaite it

jlm6740

Thanks for the info. I have the same combination and have notice the same noise from time to time. My brother had a Tacoma that made a noise kind of like it and it turned out to be a problem with the rear springs.

I'll have mine checked out.

tonzmn

Unfortunately, I don't know much more to be more specific, however, I remember the service writer saying they had to pull the links? (hope that's the right term) from the rear differential into the transmission and re-lube them. He said they did not have to get into the transmission which makes sense to me - my trans. isacting fine.

After driving it, I do notice a little more "tightness" in the ride (may just be my imagination), but they definitely made a huge improvment.

I suggest calling your dealer and asking them to tell you about the bulletin that's out on the rear end torque problem. My service writer knew what I was trying to tell him before I had the first sentence out of my mouth!

Hope this helps!

neto1978

The bump that you feel is normal and is the transmission completing a downshift into first gear.

Many other transmissions will complete this shift just as the vehicle comes to a stop and some will go to 1st as you lift off the brake or push the accelerator after being stopped, the torque management system and electronic transmission control module on the new GMT900 products is programmed to complete the 2-1 shift while stopped in certain conditions.

2007 Lt1/5.3/3.73

thanks for the info, and yes it sounds like its shifting back into 1st gear, but it makes a distinct clunk noise and u can feel it in the truck somewhat? that seems a little unusual! I worry that it may get worst with time and would like to get the issue resolved while the truck is under warranty

tonzmn

Mine was way more than the trans. downshifting. Sometimes it was so violent, I thought someone had rear-ended me!

Itwas the differential as it connects to the transmission - my trans. is perfect and they didn't have to get into it at all. They kept the truck for half a day and I've been driving it for 2 weeks now with no more clunks!
Don't wait another week. It's covered under warranty (and a special bulletin) and it's so nice to not have any more clunking.

jlm6740

I had my truck in the dealership last couple of weeks for this issue. First they thought it was aproblem with the leaf springs. They had to order in some spacers to try to see if that would fix it.

The spacers didn't resolve the problem, so they did more research and apparently there is a bulletin out regarding lubing / re-lubing the splines on the transmission tailshaft. Apparently the yoke tends to bind on hard braking and will make a popping sound then or when the brakes are released.

Seems to have fixed the issue for me.