2000 Chevy Silverado shudder

Tiny
DAKOTA2010
  • MEMBER
  • 2000 CHEVROLET SILVERADO
  • V8
  • 4WD
  • AUTOMATIC
  • 87,000 MILES
I was told I have a launch shudder problem, vibration at take off worst pulling a trailer at take off but stops after 10 sec. Was told to go to a 1 pc driveshaft from a 2 pc driveshaft from chevy garage, others told me that won;t fix the problem could be a suspension problem.I have replaced all u-joint plus caarier bearing, still the same, help please
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Sunday, March 28th, 2010 AT 12:21 PM

11 Replies

Tiny
FACTORYJACK
  • EXPERT
It could be a result of driveline working angles that are out of limits. The reason it amplifies when towing, is the housing twists more due to increased load, and the angles at extremes, are greater. It may be a situation where the driveline angles need to be evaluated, and corrected most often, by shimming the rear axle housing. Is this vehicle still at stock height, or has it been lifted?
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Sunday, March 28th, 2010 AT 10:14 PM
Tiny
DAKOTA2010
  • MEMBER
The height of the truck is still stocked, I will look in getting the info you provided a looking at, so a 1 pc driveshaft is not the answer at this point I take it.
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Monday, March 29th, 2010 AT 11:01 AM
Tiny
DAKOTA2010
  • MEMBER
Another question is this a big issue and costly thing to do and should I take it to the chevy dealer to tackle, this issue has been on going for months to get fixed and it is driving me insane, I don't want to tear anything else up;i like this truck.
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Monday, March 29th, 2010 AT 11:12 AM
Tiny
FACTORYJACK
  • EXPERT
I see where the info to change from 2-piece to 1 piece had come from. It is in a factory bulletin. I would suppose if it fits the criteria from the bulletin, as far as models, that would be the next step in eliminating it. I had misunderstood, and was going into the technical aspect of cause and correction. If it is in bulletin form, and it matches the criteria, then I would suggest that as a start. It would even be a more probable fix since the ride height has not been altered. I will give you a copy of that bulletin:
#01-04-17-001B: Launch Shudder/Vibration on Acceleration (Install New One-Piece Propeller Shaft) - (Feb 21, 2002)

Subject: Launch Shudder/Vibration On Acceleration (Install New One-Piece Propeller Shaft)

Models: 1999-2002 Chevrolet and GMC K2500/3500 Extended Cab Long Box and Crew Cab Short Box Pickup Models

With Automatic Transmission

This bulletin is being revised to add model information, remove procedure steps and change parts information. Please discard Corporate Bulletin Number 01-04-17-001A (Section 04 -- Driveline Axle).

Condition
Some customers may comment on a vibration during acceleration from 0-40 km/h (0-25 mph). This may also be referred to as launch shudder. This condition may be more noticeable when the vehicle is carrying cargo or is used for towing.

Correction
A new propeller shaft is available for service to correct this condition. This new propeller shaft is a one-piece design and will replace the current two-piece design.

Install a new one-piece propeller shaft on affected vehicles. Refer to the service procedure and the parts information listed below. Match the affected vehicle with the appropriate propeller shaft. Refer to the usage information below. This fix does not apply to the Chassis/Crew Cab Models (K35943).

Remove the propeller shaft assembly and the center bearing. Refer to the Propeller Shaft - Two Piece procedure in the Propeller Shaft sub-section of SI2000. For this bulletin, it is not necessary to mark the components for re-assembly.
Center Bearing Support Bracket

Important: The center bearing support bracket (1) must be removed in order to provide enough clearance for installation of the one-piece propeller shaft. Avoid damaging the crossmember during removal of the center bracket. For proper clearance, no more than 13 mm ( in) of the bracket may remain on the crossmember after removal.

Remove the center bearing support bracket from the kick-up crossmember using a cut-off wheel.
After removal of the center bearing support bracket, grind the rough metal edges smooth that remain on the crossmember.
Coat the exposed metal surfaces with frame coating using the information found in the applicable Service Manual and GM Refinish Material Booklet #4901M-D-2002 (English) or #4901M-D-F2002 (French).
Install the new propeller shaft. Refer to the Propeller Shaft Replacement - One Piece in the Propeller Shaft sub-section of SI2000 for installation guidelines and yoke retainer tightening specifications.
Parts Information
P/N
Description
Usage

15077431
Shaft Asm.- Prop
K25953 w/ LQ4, MT1, C6P

(99-00 8600# GVW)

15077434
Shaft Asm.- Prop
K25953/35953 w/ M74 (Allison Trans)

15077435
Shaft Asm.- Prop
K25953 w/ LQ4, MT1

(HD Model 9200# GVW)

15077436
Shaft Asm.- Prop
K35953 w/ LQ4, MT1

(11,400# GVW)

15093466
Shaft Asm.- Prop
K25743 w/LQ4, MT1

(HD Model 9200# GVW)

15093467
Shaft Asm.- Prop
K25743 w/M74 (Allison Trans)
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Tuesday, March 30th, 2010 AT 11:27 PM
Tiny
DAKOTA2010
  • MEMBER
THE 1 PC DRIVESHAFT KEEPS COMING UP, YESTERDAY WE JACKED THE BACKEND UP AND PUT THE TRUCK IN DRIVE AND LET IT GET ABOUT 7-10 MPH HR AND NOTICED THE DRIVESHAFT HAD A SLIGHT WOBBLE/TWEEK/VIBRATION/GOING INTO THE REAREND, BUT THE FRONT SHAFT WAS FINE, COULD THE SHAFT BE BENT OR OUT OF BALANCE WOULD IT BE WORHT TAKING OFF AND CHECKING TO SEE IF IT IS BENT/OUT OF BALANCE. CHANGED REAREND LUBE ALSO YESTERDAY

I APPRECIATE YOUR INPUT THANKS
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Wednesday, March 31st, 2010 AT 8:01 AM
Tiny
FACTORYJACK
  • EXPERT
I would think that if it were imbalance, or untrue, the vibration would come and go. By that I mean, as it rotates it will reach a speed where it cancels, and reappears. I would think that would occur at higher propshaft speeds and kind of harmonically come and go, not at a launch from a stop. The service bulletin doesn't give any specifics on why it happens, and what changes when going from a 2pc to a 1pc. Does the vehicle fit the criteria of 2500/3500 Ext Cab long box, or Crew Cab short box, does this bulletin even apply. To be honest with you, if the vehicle fit the criteria, and was still under warranty, I would have no hesitation in performing the retrofit from 2pc to 1pc. I will offer you some info on the subject, it can be somewhat complex topic.
Diagnosing Second-Order Driveline Vibration
Second-Order Driveline Vibration Theory

A faulty universal joint (U-joint) may cause a vibration that occurs twice for each rotation of the propeller shaft. This type of vibration is called a second-order vibration.

Second-order driveline vibrations are independent of runout or balance of a driveline component.

The following description of basic U-joint theory will help you to understand where second-order driveline vibrations originate and why they occur.

" As the propeller shaft rotates, the U-Joint speeds up and slow down twice for each rotation of the propeller shaft.

" The acceleration and deceleration of the U-Joint is not visible. If there is vibration in the U-Joint, the acceleration and deceleration will be audible and tactile.

" Compare the U-joint in a vehicle to a universal-type socket. When a universal-type socket is used to tighten a bolt, the socket will bind and release as the socket turns toward 90 degrees. The bind and release occurs twice for each revolution of the socket.

" The U-joint in a vehicle works in the same way as the universal-type socket. The bind and release effect is directly proportional to the angle that the U-joint operates: the greater the angle, the greater the effect.

" Because the transmission output speed is constant, the binding and releasing of the U-Joint is better described as an acceleration and deceleration which occurs twice for each revolution of the propeller shaft.

" If the propeller shaft is running slowly, the accelerating and decelerating effect is visible. The acceleration and deceleration may create a vibration due to the fluctuations in force that are generated at high speeds.

Canceled Out Driveline Angles


http://www.2carpros.com/forum/automotive_pictures/309872_182180_1.jpg



(1) Front Working Angle
(2) Rear Working Angle

Engineers design drivelines in order to compensate for the accelerations and decelerations in order to produce a smooth, constant flow of power, as listed below:

" The transmission drives the front yoke of the propeller shaft at a smooth and constant speed.

" The first U-joint causes the power to fluctuate twice for each revolution of the propeller shaft.

" The second U-joint, oriented 90 degrees from the first U-joint, causes the power to fluctuate opposite that of the first U-joint.

" As the first U-joint slows down, the second U-joint speeds up.

This design causes one U-joint to cancel out the effect of the other U-joint. The cancelled effects result in a smooth, constant power flow from the output yoke of the propeller shaft.

Second-order driveline vibrations occur when the cancellation becomes unequal between the front U-joint and the rear U-Joint.

The main objective of this section is to correct the conditions that interfere with the proper cancellation effect of the U-Joint. The most common condition, especially where the launch shudder is concerned, is incorrect driveline working angles. Other factors may aggravate the condition.

Address the following factors before you attempt to measure or correct the driveline working angles:

" Worn, failed, damaged or improperly installed U-Joint

" Worn, collapsed, or improper powertrain mounts

" Incorrect vehicle trim height adjustment for the front suspension which aggravates the launch shudder

" Incorrect trim height adjustment for the rear suspension

" Trim height inspection includes trim heights that are too low or too high. The following vehicles fit into this category:

- Vehicles equipped with aftermarket lift kits

- Vehicles constantly loaded with cargo

- Custom conversion vans

On rear drive vehicles, the pinion nose tilts upward as you lower the rear trim height.

If a second-order driveline vibration exists after you correct these conditions, measure and correct the driveline angles.

If the complaint is present only with cargo in the vehicle, perform the measurements with the vehicle fully loaded. Once you correct a second-order driveline vibration with the vehicle loaded, the vibration may reappear with the vehicle unloaded. The reverse of this condition is also true. You may have to reach a compromise with the customer in this case.

Second-Order Driveline Vibration Symptoms
Second-Order driveline vibration has the following signs and symptoms:

" The vibration is always related to vehicle speed.

" The vibration is usually torque-sensitive.

" The vibration is worse under a torque load.

Launch shudder is the most common complaint of a second-order driveline vibration.

Launch shudder occurs during acceleration from 0-40 km/h (0-25 mph). Launch shudder appears as a low frequency shake, wobble, or shudder. The driver may feel the vibrations in the seat or steering wheel at low speeds of 0-24 km/h (0-15 mph). The vibrations will increase in frequency as the vehicle speed increases. Launch shudder feels more like driveline roughness at higher speeds of 24-40 km/h (15-25 mph). At speeds greater than 40 km/h (25 mph) the vibration usually disappears.

Rear Axle Wind-Up
Rear axle wind-up may cause launch shudder even when all of the working angles are within specifications. Rear axle wind-up occurs when heavy torque during acceleration causes the pinion nose to point upward. In order to compensate for axle wind-up, tip the pinion nose downward. Install the axle shims incrementally, performing a road test after each shim. Add shims until the road test indicates that the shudder is eliminated.

Rear Axle Shims
Wedge shims of different sizes are available through the parts' system and independent suppliers for the purpose of shimming the rear axle angle. Wedge shims are available in 2, 3, and 4 degrees.


http://www.2carpros.com/forum/automotive_pictures/309872_182361_1.jpg



(1) Axle Tube
(2) Upper Plate
(3) Spring
(4) Lower Plate
(5) Shim
(6) Button

Caution: Never attempt to shim a rear axle using anything except shims that are designed for this purpose. Failure to do so will result in the shims falling out and a loss of vehicle control and that could cause personal injury.

Install the shims in order to increase or decrease the angle of the rear axle pinion. Install the shims between the leaf spring and the spring seat. Depending on the design of the suspension (leaf spring on top or underneath the axle), and the direction of the desired change, install the shims with either the thick side toward the front of the vehicle or toward the rear of the vehicle.

Important: After installing the shims, ensure that the U-bolt has 2 or 3 threads above the nut. Ensure also that the center bolt, located in the spring seat, is long enough to seat in the locator hole. If these two conditions do not exist, use longer U-bolts and center bolts. Longer U-bolts and center bolts are available through local spring shops.
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Wednesday, March 31st, 2010 AT 11:22 PM
Tiny
DAKOTA2010
  • MEMBER
This truck is a 2000 silverado 2500 ext. Cab/3rd dr/longbed/ 4x4 this truck is the same as out of factory

thanks scott
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Thursday, April 1st, 2010 AT 12:23 PM
Tiny
DAKOTA2010
  • MEMBER
JUST FOUND OUT THAT MY REAR SHAFT NEEDS REPLACED, FRONT SHAFT IS FINE, BUT CHEVY DOES NOT MAKE THE REAR SHAFT ANYMORE THEY WANT YOU TO GO TO A 1 PC SHAFT, DO YOU THINK I SHOULD GO TO A 1 PC OR GET THE REAR SHAFT REBUILT FOR THE LONG RUN.
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Thursday, April 1st, 2010 AT 3:52 PM
Tiny
FACTORYJACK
  • EXPERT
Is the rear shaft need, probable to your shudder? This would influence your decision on repair of the shaft, if it was going to correct your original concern. Since there is no testimonials on 1pc vs. 2pc, and I don't know anyone that has had the retrofit to address any concern, I suppose it would fall into cost. What is the price of the 1pc, versus repair of the rear shaft. Repair of a shaft is usually relatively inexpensive, some welding, a balance, and thats about it. If the repair is proposed to correct your shudder, I would have the repair.
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Thursday, April 1st, 2010 AT 11:37 PM
Tiny
DAKOTA2010
  • MEMBER
1 pc shaft/$700.00

rebuild rear shaft/$140.00

I WILL REBUILD AND SEE WHAT HAPPENS/IF NEEDED I WILL GO 1 PC.

THANK YOU FOR YOUR HELP AND INFO

SCOTT
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Friday, April 2nd, 2010 AT 6:49 AM
Tiny
2CARPROS LINSEY
  • MEMBER
Hi Dakota2010,

Thank you for using 2CarPros. Com. We appreciate your donation and look forward to helping you in the future.
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Friday, April 2nd, 2010 AT 11:41 AM

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