My Account
My Garage
Shopping Cart

Shopping Cart

0 items in your Cart
View Cart
Subtotal
Track
My Order
MY GARAGE Select Vehicle
MY GARAGE

KYB Suspension KG4521 Gas-a-Just Monotube High Pressure Gas Shock Absorber

(Ford Mustang 1984-2002, Thunderbird 1984-88; Volkswagen Beetle 1952-66, Transporter 1955-79, Karmann Ghia 1955-65, Campmobile 1968-74 + 4 more models)

Part of: KYB Suspension Gas-a-Just Monotube High Pressure Gas Shock Absorber

Other options in this family: KYB Suspension KG54317 KYB Suspension KG5462 KYB Suspension KG4752 KYB Suspension 554348 KYB Suspension KG5440

Manufacturer

Picture for manufacturer KYB Suspension

Part Number

KG4521
15 reviews
Sale Price

$39.34

In Stock (7)

delivery box

Usually delivered within 2 days

Check out with

ApplePay
Authorize Seller Badge
No Hassle Returns

No Hassle Returns

Live-in-stock inventory

Live-in-stock inventory

Fitment guaranteed

Fitment guaranteed

Product Details

The KYB Gas-a-Just KG4521 is a high-performance monotube shock absorber engineered to deliver superior handling and control for demanding driving conditions. Unlike traditional twin-tube designs, this monotube configuration provides instant response and fade-free performance that adapts automatically to your driving needs.

Advanced Monotube Technology:

  • Dual-chamber design with separate hydraulic and gas chambers for optimal performance
  • Air-free hydraulic piston and valve area ensures consistent responsiveness and precise control
  • High-pressure nitrogen gas chamber with floating piston provides progressive damping
  • Eliminates shock fade caused by aeration during aggressive driving
  • Instant automatic adjustment from comfortable cruising to performance handling on demand
  • Larger piston diameter than twin-tube designs for improved heat dissipation
  • Direct gas pressurization maintains tire contact with the road surface

The Gas-a-Just design excels in applications requiring firmer damping control, making it ideal for vehicles with heavy loads, performance upgrades, or spirited driving. The monotube construction and nitrogen gas charge work together to maintain consistent damping characteristics under all conditions, delivering both comfort during normal driving and enhanced stability when you need it most.

Products specifications

Fits

Ford Mustang 1984-2002, Thunderbird 1984-88; Volkswagen Beetle 1952-66, Transporter 1955-79, Karmann Ghia 1955-65, Campmobile 1968-74, Squareback 1966-73, Fastback 1966-73; Mercury Cougar 1984-88, Capri 1984-86

FEATURE AND BENEFIT 1

ADDS UP TO 25% MORE DAMPING PERFORMANCE OVER ORIGINAL EQUIPMENT SHOCKS

Compressed Length

10.55

Extended Length

16.26

Stroke Length

5.71

Feature and Benefit 2

COMPONENTS AND VALVING DESIGNED SPECIFICALLY FOR YOUR VEHICLE

Lower Mount Type

E2(12X32)

Upper Mount Type

E2(12X32)

Feature and Benefit 7

ELECTRONIC SAFETY SYSTEMS DEPEND ON THE SUSPENSION, BRAKES AND TIRES OPERATING AS THE VEHICLE MANUFACTURER INTENDED. THE KYB GAS-A-JUST HELPS KEEP ELECTRONIC SAFETY SYSTEMS PERFORMING AS DESIGNED.

Feature and Benefit 5

FLUID LEAKING CAN BE A CAUSE OF SHOCK FAILURE, THE KYB GAS-A-JUST HAS AN ULTRA-SMOOTH TRIPLE CHROME PLATED CHROME PISTON ROD TO REDUCE SEAL WEAR

Feature and Benefit 3

GAS-A-JUST MONOTUBES INCLUDE ADDITIONAL DAMPING OVER OE DESIGN FOR VEHICLES THAT WORK, TOW, AND HAVE LARGER, HEAVIER TIRES & WHEELS

Feature and Benefit 4

HIGH PRESSURE MONOTUBE DESIGN SEPARATES THE GAS AND OIL FOR FADE FREE OPERATION AND INSTANT RESPONSE

B-stop

N

R-stop

N

Feature and Benefit 6

THE HIGHER GAS PRESSURE OF THE KYB GAS-A-JUST RESPONDS QUICKLY TO IMPROVE STEERING RESPONSE

Dust Cover Included

Y

Internal Rebound Spring

N

Tires are exactly what I ordered and delivery was on time via FedEx.

Good so far .best price around

Got the product quickly

Best price. Website is easy to navigate, and tye check out process was quick and easy.

It was easy but wanted to talk to some one don't see a customer service number that would be helpful

Lots if Auto parts in stock with cheaper prices. Wish you accepted coupons.

You had a part I couldn't find elsewhere

I searched the internet high and low for the JKS Quicker Disconnects and almost thought it was a scam when I found them for this price! The order was simple and the shipping was fast. I could not be happier!

Great communication, super fast shipping, and product just as described. Very happy, thank you.

I found them doing a search for a clutch kit, they are hands down one of the easiest companys to work with and the prices cant be beat..... I looked everywhere

I would not hesitate buy from Autoplicity again!!! A+++

best price I could find...just ordered the product. Hope everything else is as good.

Autoplicity had the best price anywhere! I looked everywhere for the airaid intake system and they had it in stock. Great company!

Excellent price on kirkey seats! I will be buying from them again. Thanks for the prompt service

Best prices on the web, shipping charges were as well, ordered on Tuesday received on Saturday of same week!!

Share icon
Return Policy
Returns are easy at THMotorsports

Not happy with a purchase? No problem. We've made returning items as easy as possible. And most purchases can be returned for free for 30 days. Learn more about our Returns Policy