Jerks backward when starting - 2011 Silverado 4.3L Automatic
October 25th, 2012, 3:45 PM
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Jerks backward when starting - 2011 Silverado 4.3L Automatic
Jerks backward when starting - 2011 Silverado 4.3L with 4L60-E Automatic transmission.
Ok, I know I should be sitting in the truck, buckled up, foot on the brake, etc... but my truck also shouldn't move when I turn the ignition key.
After work, I open the door, set my lunch box, safety glasses, etc. in the truck and reach in and turn the ignition. I usually cover my seat and take off a long-sleeve shirt while the truck is running before I get in.
This truck only has 4300 miles on it and it sometimes jerks pretty significantly when I turn the key and the engine starts. It is in PARK but it is as if someone started it in REVERSE and then immediately slammed it in PARK. It doesn't do this all the time but it has done it several times in the past month.
The truck usually jumps back 2 to 4 inches but one time it went about 6 or 8 inches and the door hitting me in the shoulder was enough to knock me off balance and to the ground. It hasn't done it ever when I've taken it to the dealer, it seems like it must sit for a while before it will repeat this action. If I come home and shut it off and restart it several times, it never repeats.
What is wrong with this thing?
Ok, I know I should be sitting in the truck, buckled up, foot on the brake, etc... but my truck also shouldn't move when I turn the ignition key.
After work, I open the door, set my lunch box, safety glasses, etc. in the truck and reach in and turn the ignition. I usually cover my seat and take off a long-sleeve shirt while the truck is running before I get in.
This truck only has 4300 miles on it and it sometimes jerks pretty significantly when I turn the key and the engine starts. It is in PARK but it is as if someone started it in REVERSE and then immediately slammed it in PARK. It doesn't do this all the time but it has done it several times in the past month.
The truck usually jumps back 2 to 4 inches but one time it went about 6 or 8 inches and the door hitting me in the shoulder was enough to knock me off balance and to the ground. It hasn't done it ever when I've taken it to the dealer, it seems like it must sit for a while before it will repeat this action. If I come home and shut it off and restart it several times, it never repeats.
What is wrong with this thing?
October 28th, 2012, 8:58 PM
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Hey man I don't know how helpful this will be check out this thread that kind of has the same thing you're talking about
https://chevroletforum.com/forum/sil...-issues-49641/
https://chevroletforum.com/forum/sil...-issues-49641/
October 28th, 2012, 10:06 PM
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INFORMATION
Bulletin No.: 08-07-30-026A
Date: May 17, 2011
Subject: Information on Slight Vehicle Movement in Park at Start Up After Cold Soak
Models:
2012 and Prior GM Passenger Cars and Light Duty Trucks
Equipped with Automatic Transmission
Supercede:
This bulletin is being revised to add the 2010-2012 model years. Please discard Corporate Bulletin Number 08-07-30-026 (Section 07 - Transmission/Transaxle).
Some vehicles may rock or move slightly forward or rearward while in park at start up after cold soak. This condition may be accompanied by a clunk noise. This is a slight movement that is more often seen visually, rather than felt, when viewed from the outside and using the auto-start feature, if equipped.
This slight movement is due to the residual transmission fluid in the clutch packs that creates a partial apply on start up. This movement is stopped by the parking pawl and/or transmission fluid exhausting completely from the clutch packs.
This slight movement has no adverse affects on the transmission and no repair should be attempted. This condition is normal. This can be verified by comparing with another identically built vehicle under the same cold conditions.
To prevent this condition from occurring, the parking brake should be utilized as per the Owner's Manual recommendations anytime the vehicle is parked.
Bulletin No.: 08-07-30-026A
Date: May 17, 2011
Subject: Information on Slight Vehicle Movement in Park at Start Up After Cold Soak
Models:
2012 and Prior GM Passenger Cars and Light Duty Trucks
Equipped with Automatic Transmission
Supercede:
This bulletin is being revised to add the 2010-2012 model years. Please discard Corporate Bulletin Number 08-07-30-026 (Section 07 - Transmission/Transaxle).
Some vehicles may rock or move slightly forward or rearward while in park at start up after cold soak. This condition may be accompanied by a clunk noise. This is a slight movement that is more often seen visually, rather than felt, when viewed from the outside and using the auto-start feature, if equipped.
This slight movement is due to the residual transmission fluid in the clutch packs that creates a partial apply on start up. This movement is stopped by the parking pawl and/or transmission fluid exhausting completely from the clutch packs.
This slight movement has no adverse affects on the transmission and no repair should be attempted. This condition is normal. This can be verified by comparing with another identically built vehicle under the same cold conditions.
To prevent this condition from occurring, the parking brake should be utilized as per the Owner's Manual recommendations anytime the vehicle is parked.
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