Axiom Supply Shock Extension Kit | 0-2" Front Lift | OE Shocks Only | 1999-2006 Chevy Silverado/GMC Sierra 1500 6-Lug 4WD | SKU AXGMSE99
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Before ordering, verify your vehicle details, current setup, and SKU with OFAS fitment support so your upgrade matches your build.
Shipping & Delivery
Free shipping is available within the lower 48 U.S. states. Large or heavy items may ship by freight, and delivery timing can vary by warehouse, carrier, and product availability.
Fitment, Shipping & Product Support
The Axiom Shock Extension Kit (SKU AXGMSE99) is engineered for 1999–2006 Chevrolet Silverado 1500 and GMC Sierra 1500 6-lug, 4WD trucks running 0–2" of front lift via a leveling key set or mild lift system. When the front end is raised, the factory shock mounts move relative to the shock body — without repositioning, the shock can operate outside its designed travel range, causing over-extension at full droop, premature wear, and reduced damping performance. This extension repositions OE or OE-equivalent shocks to maintain correct travel and preserve ride quality. High-strength metal construction, corrosion-resistant finish. Direct bolt-on installation — no cutting or modification required.
For best results, pair with a torsion key leveling kit and a premium aftermarket upper control arm kit.
Component Specifications
| Spec | Detail |
|---|---|
| SKU / Part Number | AXGMSE99 |
| Brand | Axiom Supply |
| Type | Shock extension kit |
| Lift Range | 0–2" front lift |
| Construction | High-strength metal, corrosion-resistant finish |
| Shock Compatibility | OE shocks or OE-equivalent only — NOT for plus-length/extended-travel shocks |
| Installation | Direct bolt-on — no cutting or modification required |
| Drivetrain | 4WD |
| Application | 1999–2006 GM 1500 6-lug — leveling key sets and mild front lift systems |
| Sold As | Kit |
What Is and Is NOT Included
| Item | Included |
|---|---|
| Shock extension kit (both sides) | ✓ |
| Mounting hardware | ✓ |
| Torsion key leveling kit | ✗ NOT included — sold separately, pair for a complete leveling install |
| Upper control arms | ✗ NOT included — recommended pairing for best alignment geometry |
| Compatibility with plus-length aftermarket shocks | ✗ NOT supported — OE/OE-equivalent shocks only |
When to Use Shock Extensions
- After installing a torsion key leveling kit that raises the front suspension 0–2"
- When factory (or OE-equivalent) shocks are topping out or over-extending at full droop after a leveling installation
- Not intended for use with plus-length or extended-travel aftermarket shocks — confirm shock compatibility before installing
GM Shock Extension Platform Guide
| Platform | Lift Range | Notes |
|---|---|---|
| 1999–2006 GM 1500 6-Lug, 4WD (this listing) | 0–2" | AXGMSE99 |
| 2001–2010 GM 2500HD/3500HD | 0–2" | Different SKU — AXGMSE10 |
| 2011–2026 GM 2500HD/3500HD | 0–2" | Different SKU — confirm with us |
Verified Fitment
| Vehicle | Years | Lug Pattern | Drivetrain | Status |
|---|---|---|---|---|
| Chevrolet Silverado 1500 | 1999–2006 | 6-lug | 4WD | ✓ |
| GMC Sierra 1500 | 1999–2006 | 6-lug | 4WD | ✓ |
| Silverado/Sierra 1500 | 2007 and newer | Any | Any | ✗ Switched to coil-spring front suspension — different shock mounting geometry |
| Silverado/Sierra 1500 | 1999–2006 | 4-lug | Any | ✗ Different front suspension geometry |
| Silverado/Sierra 2500HD/3500HD | Any | 8-lug | Any | ✗ Different shock mounting — order the correct HD shock extension kit |
| Front lift exceeding 2" | — | — | — | ✗ A longer extension is required |
Critical Compatibility
| Configuration | Notes |
|---|---|
| Plus-length / extended-travel aftermarket shocks | NOT supported — installing this extension on a plus-length shock can result in catastrophic parts failure |
| 2007 and newer Silverado/Sierra 1500 | Does not fit — coil-spring front suspension uses different shock mounting geometry |
| 4-lug Silverado/Sierra 1500 | Does not fit — different front suspension geometry than 6-lug models |
| 2500HD/3500HD | Does not fit — different shock mounting, requires a different Axiom HD-specific kit |
| Front lift exceeding 2" | A longer extension is required for correct shock travel |
| Aftermarket upper control arms | Recommended pairing for proper alignment geometry at the new ride height |
Common Questions
How do I know if my truck is 6-lug or 4-lug?
Count the wheel lugs. 6-lug 1999-2006 Silverado/Sierra 1500 trucks use a different front suspension setup than 4-lug models — this kit is for 6-lug only.
Can I use this with upgraded aftermarket shocks?
Only if they're OE-length or OE-equivalent. This extension is not compatible with plus-length (extended-travel) aftermarket shocks — using it with one can cause catastrophic failure. Confirm your specific shock's length spec before installing.
Does this fit my 2008 Silverado 1500?
No. The 2007+ Silverado/Sierra 1500 switched to a coil-spring front suspension with different shock mounting geometry. This kit is for the 1999-2006 torsion-bar platform only.
Does this fit a 2500HD?
No. HD trucks use 8-lug wheels and a different shock mounting setup — order the correct Axiom HD-specific shock extension kit instead.
The Obsidian Take
The AXGMSE99 is for the 1999-2006 Silverado/Sierra 1500 6-lug owner installing a 0-2" leveling key set who wants the front shocks repositioned correctly rather than running them over-extended at full droop. Direct bolt-on, no cutting, pairs well with a torsion key leveling kit and upper control arms for a complete, properly-geometried lift.
The one rule that matters most: this is for OE or OE-equivalent shocks only. If you're planning to run plus-length aftermarket shocks, this extension is not the right approach — confirm shock compatibility before installing to avoid a potentially catastrophic failure.
Non-Returnable Notice: Once installed, this kit is non-returnable. Confirm shock type (OE-length only), lug pattern, and front lift height before ordering.
Manufacturer Data Disclaimer: Specifications sourced from Axiom Supply and authorized distributor documentation. Obsidian Forged Auto Supply is an authorized Axiom Supply dealer. Manufacturer specifications are subject to change without notice.