IK1700017 ­ LT & LoneStar vibration at highway speeds

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Countries:

CANADA, UNITED STATES Document ID: IK1700017

Availability:

ISIS, FleetISIS, NotSIR

Revision:

20

Major System:

WHEELS

Created:

9/19/2017

Current Language: English

Last Modified: 6/4/2018

Other Languages: NONE

Author:

Viewed:

Mark Ehlers

4514
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9

Title : LT & LoneStar vibration at highway speeds
Applies To : LT Series & LoneStar (low miles)

CHANGE LOG
Please refer to the change log text box below for recent changes to this article:
06/04/2018- Added increased isolation carrier bearing
05/17/2018- Added template for recording driveline runout in step 8. Added LoneStar.
04/26/2018­ Revised driveline diag. and added worksheet for driveline shop
04/09/2018- Added link to Shimmy IK
02/02/2018- Removed carrier bearing info
01/30/2018- Revised title and "applies to"; removed build dates, added tips
11/07/2017- Add link to IK0600020 "Determine Wheel Speed or Driveline Vibration using a Smart Phone and Free VibSensor Application"
10/30/2017 ­ Reformat to step based. Reordered and steps.
10/13/2017- Added inspect for driveshaft balance weights present
10/09/2017­ Added sheet for tire shop to use
10/05/2017- improved links, added tire flat-spot inspection, added torque arm
09/29/2017 - Initial Article Release





DESCRIPTION
This article applies to LT & LoneStar vehicles that experience an objectionable vibration felt in the seat, floor, or the steering wheel at highway speeds.
Many of the diagnostic processes in this article could also apply to other truck models.

As of 6/4/2018

If your dealer has sucessfully corrected a vibration on a new LT or LoneStar (with a sleeper) by rebalancing the drivelines at your local driveline shop and you ha
truck with the the same symptom:
1. Use the phone ap to verify the source of the vibration is the driveline
2. Open a case file and attach the VibSense result
3. In the case request a "improved isolation carrier bearing"

SYMPTOM(s)
An objectionable vibration is felt in the seat, floor, or the steering wheel. Mirror shaking might also occur (at highway speeds)

SPECIAL TOOL(s) / SOFTWARE

Tool Description

Tool Number

Tire runout gauge

4532000

Comments

Instructions

With Vibration
Diagnostic App

IK0600020

Tire pressure gauge
Tire marker / grease
pen
Smartphone or tablet
Tools Resource Center

SERVICE PARTS INFORMATION

https://evalue.internationaldelivers.com/service_kb/DocTool/ArticleViewer.aspx?ControlID... 7/2/2018

IK1700017 ­ LT & LoneStar vibration at highway speeds

Kit Description

Part Number

Quantity
Notes
Required

KIT U-JT BOLT & RET SPL-250

2500675C91

as needed

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DIAGNOSTICS

Step Action
DIAGNOSTIC:

Decision
Yes. Go to Step 2

Does the LT have a validated objectionable highway speed (45 mph+) vibration
(and not at lower speeds)?
1

Its highly recomended to interview the driver and drive the unit yourself. Take No. Article does not Apply
note if the vibration only occurs under load, or only bobtailing, etc.

Step Action

2

Decision

DIAGNOSTIC:

Yes. Go to Step 3

Does the truck have less than 30,000 miles OR has it had the vibration since
new?

No or don't know. Check service and
warranty history for prior vibration
complaints. Proceed to step 3 but be
aware that the truck could have worn
parts that are causing or contributing to
the vibration complaint. A more thorough
inspection may be needed than what is
covered in this procedure.

NOTE: If the vibration has been present since the truck was new then its very
unlikely that the vibration is caused by something worn or bent. The
diagnostic process in this article bypasses some tests and measurements that
would be performed on a higher mileage truck that did not have any prior
history of vibrations

Step Action

DIAGNOSTIC:

Determine the location of the Vibration

Decision
A steering wheel "buzz" sensation in your
hands (above 45 mph) is often driveline
related. Follow IK0600020 (below) and use a
smartphone to measure
the vibration.
A steering wheel left­to­right chop or wobble
that is severe is often a "shimmy". Go to
IK0500038

A "backslap" sensation in the seat is often
rear wheels balance / runout related. Follow
IK0600020 (below) and use a smartphone to
measure the vibration. If this is not possible
then go to Step 4.
Smartphones / Tablets with a Vibration Apps
have proven very accurate in determining if
the vibration source is wheel related or
driveline related. See IK0600020. If unable
to determine the location or source of the
vibration go to Step 4

3

Step Action

Decision

4

1.
Up and down indicates run-out or
imbalance or both .
If it gets worse as speed increases its
often balance related.
If vibration changes when vehicle is put in
neutral OR clutch is depressed (during the
vibration) then accelerate ABOVE the
vibration speed so that you can coast
down through the speed region of the
vibration. Vibrations that change when
clutch is depressed (or transmission is in
neutral) are likely driveline related.
Proceed to step 5.

DIAGNOSTIC:
Determine the type of vibration

2.

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IK1700017 ­ LT & LoneStar vibration at highway speeds

Page 3 of 8

Side to side indicates run-out, balance
and possibly irregular wear.
Steering wheel shimmy often indicates
steer tire dynamic imbalance.
Up and down indicates run-out or
imbalance or both.
If it gets worse as speed increases its
often balance related.
If it occurs at only one speed it is often
run-out related.
Proceed to step 10.
3. Low speed wobble is not a balance
problem.
A vibration while braking only indicates a
brake system problem.
Proceed to Other Resources section for
additional help.

Were you able to identify the source of the vibration?

Step Action
DIAGNOSTIC:
Suspected driveline vibration

5

Clearly mark the driveshafts and yokes for phasing purposes (Figure 1)
Flip the long shaft (Item 2) 180 degrees so that the slip shaft
(bellows) section of the driveline is closer to the rear axle. (see Figure 2).
When installing, make sure your phasing marks still line up as in Figure 1
& 2. Test drive. Is the vibration better but still objectionable?

Decision
Yes, vibration is better but still
objectionable: Go to Step 7
No, Vibration is gone: Return unit
to customer
No change: Proceed
to Step 6

Figure 1
Item 1:Slip joint bellows section of prop shaft.
Item 2: Index marks added by the technician.

It is ok for the bellows to point in either direction.

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IK1700017 ­ LT & LoneStar vibration at highway speeds

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Figure 2: Prop Shaft Flipped
Item 1: Indexing marks added by the technician still aligned
Item 2: Slip joint section of prop shaft.

It is ok for the bellows to point in either direction.