SOLVED PAGE 5: Shudder/shake/vibration when hitting bumps at highway speeds

mattbta said:

Front. And like Fless said, should be in contact with the LCA.

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Thank you. It appears I need to replace them in the front. They don't look deteriorated, but it's clear they are no longer touching the LCA, and there are wear marks on the side of the jounce bumper that seems to indicate it's collapsing way too much.

I'll report back after I've had a chance to replace them and evaluate. Thanks to everyone for your responses.

clandr1 said:

Thank you. It appears I need to replace them in the front. They don't look deteriorated, but it's clear they are no longer touching the LCA, and there are wear marks on the side of the jounce bumper that seems to indicate it's collapsing way too much.

I'll report back after I've had a chance to replace them and evaluate. Thanks to everyone for your responses.

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I replaced the front and rear jounce/bump stops. No change. I'll update again once I determine next steps.

Steering gear (linkages) and or control arms/ball joints would be my best guess.

swathdiver said:

Steering gear (linkages) and or control arms/ball joints would be my best guess.

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That was exactly what I expected, but I just finished checking ball joints, tie rods, pitman/idler arms, and nothing seems to have any play.

I'm going to take it to the tire shop and have them re-balance the tires and see if it happens to be an off balance tire that's causing it.

If that doesn't fix it, I guess I'll just replace the upper control arms and lower ball joint and see if that fixes it. Do you think it's worth replacing the lower control arm given the mileage on the original, or would just replacing the lower ball joint suffice?

have you checked your motor mounts?

clandr1 said:

That was exactly what I expected, but I just finished checked ball joints, tie rods, pitman/idler arms, and nothing seems to have any play.

I'm going to take it to the tire shop and have them re-balance the tires and see if it happens to be an off balance tire that's causing it.

If that doesn't fix it, I guess I'll just replace the upper control arms and lower ball joint and see if that fixes it. Do you think it's worth replacing the lower control arm given the mileage on the original, or would just replacing the lower ball joint suffice?

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Due to age and the work involved in replacing the ball joint itself, I would just replace the whole arm. Will be doing the same thing myself soon.

GreyStone said:

have you checked your motor mounts?

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Yes, checked them this morning as well and they seemed fine. No significant movement of the motor when in drive or reverse (brake depressed and pumping gas pedal).

So I just came across this thread:
https://www.tahoeyukonforum.com/threads/any-all-help-suggestions-welcome.119914/

I have RPO code ZW7. I'm now wondering if, when I replaced all four shocks with Bilsteins HD back in 2017, I screwed up because I did not replace the rear shocks with by not replacing the rear springs with the Nivomat eliminator springs at the same time. I installed the Bilstein shocks listed in this kit, minus the coil springs:
https://www.shockwarehouse.com/site/product.cfm/id/3010078/name/Bilstein-ZW7-Conversion-Kit

I'm thinking a logical next step would be to buy a set of springs and install them in the rear to see if that fixes my issue:
https://www.shockwarehouse.com/site/product.cfm?id=232681

Any thoughts/feedback on this?

edited:
@swathdiver I just saw this post by you in another thread - it seems that I do not have Nivomat rear since I do not have G69 in conjunction with ZW7. I'm a little confused now. Any input?

https://www.tahoeyukonforum.com/thr...7-rear-shock-replacement.110487/#post-1321057

I figured a full RPO code listing might be helpful:

1SD SLT DECOR INCLUDES: *FRONT LEATHER SEATING SURFACES *ASSIST STEPS *FULL FUNCTION FRT BUCKET SEATS *BOSE PREMIUM 9 SPEAKER SYSTEM *REAR SEAT AUDIO CONTROLS *POWER ADJUSTABLE PEDALS *VORTE
1SZ OPTION PACKAGE DISCOUNT
41U BLACK
6XN COMP FRT LH COMPUTER SEL SUSP
7XN COMPONENT FRT RH COMP. SEL SUSP
922 PEWTER/DARK PEWTER
92I DARK PEWTER INTERIOR TRIM
A31 POWER WINDOWS
AG1 POWER DRIVER SEAT ADJUSTER
AG2 POWER FRONT SEAT ADJUSTERS
AJ1 DEEP TINTED GLASS
AL0 SENSOR INDICATOR, INFLATABLE RESTRAINT
AL4 SECOND ROW CAPTAIN'S CHAIRS
AN3 BUCKET SEATS W/FRT LTHR SEATING SURFACES, DR/FRT PASS 10-WAY PWR ADJ, HEATED SEATS W/PWR LUMBAR, 2-POS DR SIDE MEMORY
AP9 CONVENIENCE NET
ARL PLANT CODE-ARLINGTON, TX
AS3 THIRD ROW 50/50 SPLIT BENCH SEAT
AU0 REMOTE KEYLESS ENTRY SYSTEM
AXP MPV VIN IDENTIFICATION
B30 COLORED - KEYED CARPETING
B58 FRT & CTR CARPETED FLOOR MATS
B85 BODY SIDE MOLDING W/BRIGHT INSERT
BVE ASSIST STEPS
C25 REAR WINDOW WASHER/WIPER
C36 REAR HEATER
C49 ELECTRIC REAR WINDOW DEFOGGER
C5U GVW RATING - 6,800 LBS
C69 REAR AIR CONDITIONING
CF5 POWER SUNROOF
CJ2 TRI ZONE AUTOMATIC AIR CONDITIONING
D07 FLOOR CONSOLE
DF5 LT SENSITIVE INT R/V MIRROR W/OUTSIDE TEMP & COMPASS
DH6 ILLUM LH & RH VISOR MIRRORS
DK8 DELUXE OVERHEAD CONSOLE
DL3 OSRV PWR HTD, FOLDING MIRRORS TURN SIGNAL, CURB-TILT
DT4 SMOKER'S PACKAGE
E52 LIFTGATE W/LIFTGLASS
EVA EVAP EMISSION REQUIREMENT
FE9 FEDERAL EMISSIONS
FK2 TORSION BAR SPRING ADJ - LH
FK3 TORSION BAR SPRING ADJ - RH
G65 LEVEL CONTROL MAN,SELF ADJUSTIN
G80 LOCKING REAR DIFFERENTIAL
GT4 REAR AXLE - 3.73 RATIO
JF4 POWER ADJUSTABLE PEDALS
JH2 BRAKE HYD POWER, DISC
JL4 STABILITRAK - REPLACES ELECTRONIC TRACTION ASSIST
K34 ELECTRONIC SPEED CONTROL
K47 HIGH CAPACITY AIR CLEANER
KNP H.D. TRANSMISSION OIL COOLER
KUP THROTTLE CONTROL ELECTRONIC
KW1 ALTERNATOR 160 AMP
L59
M30 4-SPD AUTO TRANS W/ OVERDRIVE AND ELECTRONIC CONTROL
NP5 LEATHER WRAPPED STEERING WHL
NT9 EMISSION SYSTEM FEDERAL, TIER 2 PHASE-OUT
P27 17" PREMIUM ALUMINUM WHEELS
PCR SUN, SOUND AND ENTERTAINMENT INCLUDES: *REAR SEAT ENTERTAINMENT SYSTEM *POWER SUNROOF
PDC CARGO PACKAGE
QAS P265/70R17 ALS WOL TIRES
R5C TIRE BRAND ALL BRIDGESTONE
R6J CUSTOMER DIALOGUE NETWORK
R9C ONSTAR AS STANDARD
R9G JL4 AS STANDARD
SAF SPARE TIRE LOCK
SLM STOCK ORDERS
T96 FRONT FOG LAMPS
TFE SALES INCENTIVE-COMMITMENT PLUS
U2K XM SATELLITE RADIO-OVER 130 CHNLS OF DIGITAL ENTERTAINMENT. SERVICE FEE EXTRA.1ST 3MOS.INCL
U42 REAR SEAT ENTERTAINMENT SYSTEM
UC6 AM/FM STEREO W/6-DISC CD CHANGER (REPLACES STD/OPT RADIO)
UE1 ONSTAR SYSTEM INCLUDES 1 YEAR SAFE & SOUND
UG1 HOMELINK UNIVERSAL TRANSMITTER
UJ6 TIRE PRESSURE MONITOR
UK3 STEERING WHEEL RADIO CONTROLS
UK6 REAR SEAT AUDIO CONTROLS
UQ7 BOSE PREMIUM 9 SPEAKER SYSTEM
V1K LUGGAGE CARRIER CROSS RAILS
V22 CHROME GRILLE SURROUND
V54 ROOF MOUNTED LUGGAGE CARRIER
V73 STATEMENT OF CERT. U.S.
V76 RECOVERY HOOKS
VB3 CHROME REAR BUMPER
VFF VIDEO FORMAT REGION 1 NTSC
VG3 CHROME FRONT BUMPER
VR4 WEIGHT DIST HITCH PLATFORM
VXS COMPLETE VEHICLE LABEL
XAS P265/70R17-113S WOL TIRE
YAS P265/70R17 ALS WOL
YD3 BASE EQUIP FOR SCH GVW PLATE
YD6 REAR SPRING - BASE EQUIPMENT
YE9 SLE/SLT DECOR
Z82 HEAVY DUTY TRAILERING EQUIP.
Z88 GMC TRUCK NAMEPLATE
ZM9 HOMELINK UNIVERSAL TRANSMITTER
ZMJ P265/70R15 ALS BW TIRE-SPARE
ZW7 PREMIUM SMOOTH RIDE SUSPENSION
ZY1 SOLID PAINT

We both have G65, not G69, and I sure as shit have Nivomats on my Tahoe. If you remember, were the rears you pulled off much, much thicker than the fronts? If so, those are likely Nivomats and will need new springs if going with a traditional shock.