Tranny surging at stop sign....

[Black Denial]

Hey guys, our '06 Denali (SWB) likes to kick or clunk a little when I'm at a stop light. It almost sounds like it's trying to kick down another gear although I've been stopped for a few seconds. It's not kicking me out in the intersection, but it's good I've got my foot on the brake.

I'm taking it in to the dealer tomorrow - any suggestions?

Thx.

[Dave]

Does it feel like you are being "bumped"? If so, then the air suspension is most likely the culprit and there isn't anything the dealer can or will do. It seems to happen with most TB/EN with the air suspension. So the good news is that it is nothing to worry about (providing it is the condition that I think it is) but the bad news is that it is a GM annoyance.

[Black Denial]

Yeah - my wife says it sometimes feels like someone has bumped her. Air suspension huh? Never thought of that.

How many people have this problem?

[Dave]

Here is a previous thread.

http://forums.trailvoy.com/showthread.php?t=7177&highlight=bump

The problem seems to be frequent with the people that own a TB/EN with the air suspension. I got use to mine after a while but I use to push my brake pedal down harder the first few times.

The air suspension's pump will also make a easily audible noise when it is working.

[Envoy Fan]

How many people have this problem?
I had it with my '03 Envoy SLT and air suspension. Would do it on first startup when at a stop sign or stop light. Truck in "D" and foot on brake for about 20 seconds and then the bump. Sometimes felt it two or three times at same stop. :mad: Nothing on my '05 Denali, yet. (knock on wood)

[Black Denial]

Thanks for the help guys - I just got a call from the dealer and he said what I expected: "GM says that it's a 'normal' occurence."

Basically the way he described it is that after a fairly abrupt stop on vehicles equipped with the the air leveling suspension, the system tries to adjust the "backlash" in the system and that's when you'll feel the clunking. Awesome....

I may pull the plug for the air ride until I get the thing loaded up for long hauls.

[Dave]

Or more like any stop in my case.

[Envoy Fan]

Thanks for the help guys - I just got a call from the dealer and he said what I expected: "GM says that it's a 'normal' occurence."

Basically the way he described it is that after a fairly abrupt stop on vehicles equipped with the the air leveling suspension, the system tries to adjust the "backlash" in the system and that's when you'll feel the clunking. Awesome....

I may pull the plug for the air ride until I get the thing loaded up for long hauls.

If it is GM normal, why do some trucks do it and others don't:undecided

How do you pull the plug? Are you talking the fuse?

[ScarabEpic22]

If you remove the fuse to the compressor, the back end will slowly sink down and rest on the bumpstops, you cant just pull it and forget about it. I wouldnt do it unless you want to just throw some coil springs in there instead.

[Black Denial]

^^^ Guess I hadn't thought about that, thanks. I told my wife to let the car roll a little if there's room after a quick stop. We'll see if that helps. After I found out what causes it I got it to give me a really nice "POP." Good stuff right there....