This has happen to me a few times and once to my wife (she called me and said she was rear ended the the driver drove off).

I stop for a light and then it feels like the truck has been rear ended. I look in my mirror and no one is behind me. I though I read some thing about this before on here but an hour of look has turned up nothing.

Does anyone have any ideas?

Could the spare be loose? I've had the same feeling before on my Dodge, and the spare needed to be winched up alittle. Other than that, I don't know. Good luck!
Nick

I could give that a look but it really feels like you have been rear ended. Like someone has hit my truck. Also it does not do it all the time, just, now that I think of it, during hot days.

Transmission anomoly? differential?

did you cal the computer for bigger tires? I know when my truck was stock and I put on 285's it did the same thing until I bought a programmer to cal the tire size correctly. For some odd reason too the service 4wd came on, but once I programmed it never had another problem since.

I have had the tires on for over a year now. About 20,000 miles on them. This problem just started about 2 weeks ago.

Are you stopped for awhile or just as you stop? If it happens just as you stop or 2-3 seconds there after it is a trans thing, mine has done this for 60k and not every time either.

Its right after I stop. Its like I stoped for the light but than the guy behind me didnt stop but there is no one behind me its just the truck.

Match's my 01, haven't noticed in the 05.

It's not something in your box rolling or sliding to the front by any chance?

Its right after I stop. Its like I stopped for the light but than the guy behind me didn't stop but there is no one behind me its just the truck.

Sounds to me like the torque converter clutch is failing to unlock. Do you notice if the engine is lugging down as you come to a stop?
Either that or it is trying to engage. Sounds like a trip to the dealer is possibly in your future. :(

I'm not doubting you, but can you be a little more specific..details..what exactly you are doing when this happens? stopping, taking off, hitting brake, hitting gas? complete stop? rolling?

this will help us help you more

thanks
B.

Mine does it too from time to time. It usually happens within 1-2 seconds AFTER coming to a complete stop! I always thought it was the driveline coming to a stop after spinning.

I wish I could explain it more. It happens like dieseldan723 said. Right AFTER I stop. I come to a stop light and once I am stopped completely, then the truck jumps forward. It has only happened to me 3 times and my wife once. You don't really have time to look down at the tach or anything. It really feels like someone has rear ended the truck. As the driver, you don’t expect it. It catches you off guard. When it happen to my wife, she was in heavy traffic. She thought she was hit so she pulled over and the guy behind her just drove off. She was so scared to tell me she had been hit and the other driver drove off. She drove to her brothers house and he check the truck out. No damage not even a scratch (because no one hit her, is my guess). When it has happen to me ,twice NO ONE was even behind me and the other time the car was at least a car length back.

I don’t have anything in the bed so it cant be that. If I did I would find it hard to believe this was the problem because of the violence of the jump of the truck. It like thoughts the drive back in the seat.

I was sure I had read something on here before like this but for the world of me I can't find it.

Rear axle/spring winding up like a torsion bar. Rear shocks are not Relaxing properly (delayed, maybe just One) after the stop.

Some older GM cars/trucks did this.

FWIW.

Idahofox

it sounds like the computer module that is on the fan shroud my o2 truck done the same thing.dealer replaced the module and fixed it.their should be a black cover over the module it is some kind of trans control module.

I used to drive a 99 and 2001 gasser.They would both do that from time to time it is something in the drive train at least that is what it felt like.

The problem is a slip/stick condition of the driveshaft splines. As you stop the rear of the truck raises sliding the driveshaft out of the transfercase. When you stop the truck settles back down and now the driveshaft has to slide back in but it sticks and a few seconds later it pops in causing the rearended feel.You will likely notice when you stop fast that the rear of the truck remains in the air till the driveshaft does slide in and then drops.
There is a special lubricant from GM to address this. Remove the driveshaft, brake clean the splines and blow out good. Apply the special lube to the splines in the yoke. Don't get stupid with the lube just a layer covering the splines.You must brake clean the yoke or the lube will not stick to the yoke and it wiil only last a few miles. This lube is only sold by the can and is very expensive so you may see if youu dealer will sell you some or take it in to them. Tim

Its only a year old with 20,000 miles. So she will be going into the dealer. Should I put the orginal donuts(tires) back on?

Anti-lock malfunction!

What size tires are they, 285-17's? I have H2's and never had a problem like this but heard it was possible. When you come to a stop, antiskid is suppose to be disabled (to allow the wheels to be motionless) if it briefly unlocks the wheels and quickly reengages, it might feel like you've been bumped

but it sounds like midwest knows what he is saying, pretty smart guy.

Midwest hit it on the head. Lube the splines.

I have had this problem on the odd occasion as well. I think it has happened on faster stops and have tried to follow the RPM, thinking it was the tranny delayed dropping into 1st. Midwest's explanation sounds more likely..thanks.

Any other ideas?

just a quick input i found out from the dealer if you have larger tires then your calibrated for they can void your trans part of the warranty being it will make the trans shift wrong and can cause damage just my 2 cents for what it's worth thought i would share

Big daddy I'm shure this is your problem. Just have the dealer do it.1/2 hr max time.All dealers should have the lube.

How about 30+ something gallons of fuel coming to a stop a few seconds after you and the truck have come to a stop?

That would be 30+ gallons x 8 lb/per(?)

I've noticed the "rebound" a moment after stopping.

I have had the exact same thing happen and what midwest explained was the prob. I also noticed that when I stopped fast w/ my 285's, the trans did not always shift down to first gear. It would hesitate for a second, then downshift while the truck was stopped. This caused a sudden jump, but not as bad as the drive shaft jump. I haven't had the shaft lubed. I will if the problem comes back.

special lubricant #12345879 $35.61 16oz can. That's what it's called "special lubricant" Tim

Thanks for all the help

Big Daddy, I wouldn't worry about it too much. I've had the same problem on my '94 C1500 2wd and on my '00 Suburban 1500 2wd. It would happen once in a great while. I never did anything about it and drove the '94 over 100K and the burban over 75K w/o problems