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Funny "bump" When I Start Moving After Being Stopped.

kcin16

By kcin16
in Ask A GM Technician

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kcin16 Enthusiast

kcin16

Posted
Posted

I don't really know EXACTLY how to describe this, but here goes................

 

2001 2500HD gasser, crew cab, 6.0

 

When I am sitting at a red light/stop sign, etc. & I push the gas pedal to start moving, I feel something go "bump" in the rear of the truck. It feels like there is a heavy weighted object in the bed that slides back & bumps the tailgate (yes I have checked to make sure nothing is sliding in the bed). It does not do it every time I start, but probably 90-95% of the time it does. Occassionally, if I let it roll forward or barely push the gas I don't feel it.

 

I guess tranny is first thought, but I am wondering if it might be rear-end or shocks or something like that...

 

ANY HELP/THOUGHTS are greatly appreciated!

Mighty HD Senior Enthusiast

Mighty HD

Posted
Posted

My 04 did this as well.

 

Dealer could not duplicate it, ever.

 

So I decided that I will just destroy whatever it was and then they'll fix it.

 

Every stop light when it did it, I slammed it to the floor.

 

Odd thing is eventually it cleared itself up.

 

 

I miss my 04 HD, such a beautiful truck, but what a total piece of s*it it was. In the shop once a month for the 3 years that I had it.

kcin16 Enthusiast

kcin16

Posted
  • Author
Posted
My 04 did this as well.

 

Dealer could not duplicate it, ever.

 

So I decided that I will just destroy whatever it was and then they'll fix it.

 

Every stop light when it did it, I slammed it to the floor.

 

Odd thing is eventually it cleared itself up.

 

 

I miss my 04 HD, such a beautiful truck, but what a total piece of s*it it was. In the shop once a month for the 3 years that I had it.

 

 

Yeah, I get annoyed at it also & do the same........my problem is no warranty to cover it, so I get to foot the bill :cheers:

 

It wouldn't do it when the dealership drove it????? That's typical, huh?

ChevyTech007 Enthusiast

ChevyTech007

Posted
Posted

Not a big deal. The slip yoke on you drive shaft is sticking. You can remove the drive shaft and put grease on the splines and that will fix it. For a permanent fix there is an updated slip yoke that is nickel plated. I would lube it first and see how long it last.

 

 

Part Number

Description

Usage

 

12477702

Yoke Asm., Prop Shf Slip (with u-joint) , Nickel Plated

4WD/AWD 1500 Series Ext Cab Short Box Pickups (New Style and Old Style)

 

12477704

Yoke Asm., Prop Shf Slip (with u-joint) , Nickel Plated

4WD/AWD 2500 Series Ext Cab Short Box Pickups (New Style)

 

12479383

Yoke Asm., Prop Shf Slip (without u-joint) , Nickel Plated

 

Must Be Ordered With U-Joint Kit P/N 12479126

4WD/AWD 1500 Series Silverado, Sierra Regular Cab Pickups (New Style)

 

4WD/AWD 1500 Series Suburban, Avalanche, Yukon XL, Escalade EXT, Escalade ESV with AWD (New Style)

 

K1500 Series Regular Cab Pickup, Tahoe, Suburban, Escalade (Old Style)

 

12479384

Yoke Asm., Prop Shf Slip, (without u-joint) , Nickel Plated

 

Must Be Ordered With U-Joint Kit P/N 12479126

4WD/AWD 1500 Series Tahoe, Yukon, Escalade w/ 4WD or AWD (New Style)

 

12479385

Yoke Asm., Prop Shf Slip (without u-joint) , Nickel Plated

 

Must Be Ordered With U-Joint Kit P/N 12471510

4WD/AWD 2500HD/3500 Series Silverado and Sierra Regular Cab, Long Bed Pickups with 6.0L (RPO LQ4) Engine (New Style)

 

89058876

Yoke Asm., Prop Shf Slip (with u-joint) , Nickel Plated

4WD/AWD 2500HD Series Silverado and Sierra Crew Cab, Short Bed Pickups with 5-Speed Allison Transmission (RPO M74) (New Style)

 

4WD 2500HD/3500 Series Silverado and Sierra Extended Cab Long Bed Pickups with 5-Speed Allison Transmission (RPO M74) (New Style)

 

4WD 2500HD/3500 Series Silverado and Sierra Regular Cab, Long Bed Pickups with 5-Speed Allison Transmission (RPO M74 build date before 2/2004) (New Style)

 

4WD/AWD 2500HD Series Silverado and Sierra Extended Cab, Short Bed Pickups with 5-Speed Allison Transmission (RPO M74 build date before 2/2004) (New Style)

 

89058878

Yoke Asm., Prop Shf Slip (with u-joint) , Nickel Plated

4WD/AWD 2500HD/3500 Series Silverado and Sierra Extended Cab Pickups with 6.0L (RPO LQ4) Engine (New Style)

 

4WD 2500HD Series Silverado and Sierra Crew Cab, Short Bed Pickups with 6.0L (RPO LQ4) Engine (New Style)

 

89058880

Yoke Asm., Prop Shf Slip (with u-joint) , Nickel Plated

4WD/AWD 2500HD/3500 Series Silverado and Sierra Regular Cab, Long Bed Pickups with 5-Speed Allison Transmission (RPO M74 build date after 2/2004) or 6-Speed Manual Transmission (RPO ML6) (New Style)

 

4WD 2500HD Series Silverado and Sierra Extended Cab, Short Bed Pickups with 5-Speed Allison Transmission (RPO M74 build date after 2/2004) or 6-Speed Manual Transmission (RPO ML6) (New Style)

 

12479126

U Joint Kit

4WD/AWD 1500 Series Silverado, Sierra Regular Cab Pickups (New Style)

 

4WD 1500 Series Suburban, Avalanche, Yukon XL) (Escalade EXT, Escalade ESV with AWD (New Style)

 

4WD 1500 Regular Cab Pickup, Tahoe, Suburban, Escalade (Old Style)

 

Tahoe, Yukon, Escalade w/ 4WD or AWD (New Style)

 

12471510

U Joint Kit

4WD/AWD 2500HD/3500 Series Silverado and Sierra Regular Cab, Long Bed Pickups with 6.0L (RPO LQ4) Engine (New Style)

 

88964470

Yoke Asm., Prop Sft Slip (without U joint) Nickel Plated

 

Must be ordered with U joint kit P/N 88964507

HUMMER H2

 

88964507

U-Joint

HUMMER H2

Zembonez Senior Enthusiast

Zembonez

Posted
Posted

I believe Chevytech007's diagnosis is correct. I had the very same problem in my 01 Silverado and removing and lubing the driveshaft yoke fixed it for good. It was quite a head scratcher but somebody in here suggested the fix.

 

10 minute fix!

Zembonez Senior Enthusiast

Zembonez

Posted
Posted
It fixed it for me for about 2 months, then it came right back, too lazy to fix it again

 

Try using Marine Grade wheel bearing grease inside the slpines in the yoke. (like you would use in a boat trailer wheel bearing) It stays where you put it and it only takes a little bit to do the job. Mine worked as long as I had the truck.

99silverado1500 Senior Enthusiast

99silverado1500

Posted
Posted

I think I used like Slick 50, or a similar grease. I will buy some of that marine bearing grease and see if it gets rid of it for good. If it does I will be really really happy!! That EEP every time I start out is annoying. Now to fix the sloppy 2nd gear shift and after that its pretty close to perfect.

Denali_bug Enthusiast

Denali_bug

Posted
Posted
I don't really know EXACTLY how to describe this, but here goes................

 

2001 2500HD gasser, crew cab, 6.0

 

When I am sitting at a red light/stop sign, etc. & I push the gas pedal to start moving, I feel something go "bump" in the rear of the truck. It feels like there is a heavy weighted object in the bed that slides back & bumps the tailgate (yes I have checked to make sure nothing is sliding in the bed). It does not do it every time I start, but probably 90-95% of the time it does. Occassionally, if I let it roll forward or barely push the gas I don't feel it.

 

I guess tranny is first thought, but I am wondering if it might be rear-end or shocks or something like that...

 

ANY HELP/THOUGHTS are greatly appreciated!

Genuinefine409 Enthusiast

Genuinefine409

Posted
Posted

My 2002 2500HD CC does the same thing, I just assumed it was driveline slope cause it only does it from a stop. My friend has a 2004 F250 Super Duty CC that does the exact same thing and the dealer told him its driveline slop from everything having a little freeplay and when you stop it's all one way and when you go to pull out you feel all the freeplay at once. :rolleyes: Beats me though, I'm going to try greasing the slip yoke.

Zembonez Senior Enthusiast

Zembonez

Posted
Posted
I think I used like Slick 50, or a similar grease. I will buy some of that marine bearing grease and see if it gets rid of it for good. If it does I will be really really happy!! That EEP every time I start out is annoying. Now to fix the sloppy 2nd gear shift and after that its pretty close to perfect.

Well for my sake I hope it solves it! Can't guarantee it but it sure fixed mine. It was quite annoying and I was glad to finally find out what it was. (and that it wasn't a serious problem) I originally thought I had trans issues.

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