The 4" portal is the most flexible way to give an older RZR XP 900 or XP 4 900 more clearance and more pulling power. It lifts the machine 4" right at the hubs and adds your choice of a 15% or 30% gear reduction, so you can match the setup to how and where you ride, from fast trails to rock gardens and mud holes.
Highlights
- 4" of lift at the hubs
- Choose a 15% or 30% gear reduction
- Choose cast aluminum or USA-made, CNC-machined 6061 billet aluminum housings
- Cool, quiet, precision-ground 9310 billet steel gears
- 1.5" diameter hardened 4340 steel drive shaft
- Adds 4" of width per side (8" total)
- Universal hubs set up for 4/156, 4/137, 4/115 and 4/110 bolt patterns
- All hardware, backing plates, brake lines and instructions included
- Limited lifetime warranty
Which Reduction Fits Your Riding?
- 15% for trails: keeps high speed for hills, dirt shelves and long trail days while adding the clearance to run bigger tires
- 30% for mud and rocks: a big boost in torque to turn larger tires through deep mud and crawl over boulders, and it's still usable on the road
Tire Size Guide for 4" Portals
- Up to 25": stock suspension, 15%
- Up to 26": 3-5" lift kit, 15%
- Up to 28": 1.5" forward front A-arms, 15%
- 29" to 30": 1.5" forward A-arms and 3-5" lift kit, 15%
- 31" to 35": 6" lift kit, 30%
These recommendations are meant to keep factory top speed. A larger reduction adds torque and lowers top speed.
Clearance Where It Counts
Lifting at the hub raises the whole machine, skid plate included, so rocks and stumps that used to scrape the belly pass underneath. Suspension travel and geometry stay as designed, so the RZR still handles the way it did before.
Built Strong Inside and Out
The 9310 steel gears are ground for strength and smooth running at speed. Housings are reinforced in the right places and designed around oil flow and gear loads, with no vents, since testing showed they do more harm than good.
Seals That Keep Oil In
- Oil-resistant gaskets that deteriorate more slowly than Kevlar gaskets
- Sealed input gear
- Double-lipped output seal
- Complete sealing coverage
4" or 6" Portals?
- 4": works with smaller wheels (14" and up), offers a 15% trail option and suits most riders
- 6": more lift and up to 45% reduction for the biggest tires, but needs 18" or larger wheels
Why Portals Instead of a Big Lift?
A traditional lift raises the chassis but leaves the axles at steeper angles and does nothing for gearing. A portal lift raises the hub, so the axles stay closer to their normal angle, and the gear reduction gives the engine a mechanical advantage. On an older RZR XP 900 that means bigger tires without overworking the belt and clutch, and less chance of breaking axles when you're climbing or pulling out of mud.
Real-World Riding
- Trail riders: 15% keeps the RZR quick and lets you step up a tire size or two for more grip and clearance
- Mud riders: 30% turns tall mud tires through deep holes and still lets you drive back home
- Rock crawlers: 30% adds slow, controlled torque for ledges and boulder fields, while the extra height helps the skid plate clear obstacles
Before You Order
- Choose 2-seat or 4-seat to match your machine
- Check that your wheels meet the requirements below
- Plan for the extra 8" of overall width
- Use the tire guide to see whether you'll also need A-arms or a lift kit
Fitment
| Year | Make | Model |
|---|---|---|
| 2011-2014 | Polaris | RZR XP 900 |
| 2012-2014 | Polaris | RZR XP 4 900 |
Wheel Requirements
- 14” or larger wheel required
- 14” & 15” wheels cannot exceed 4-1/2” backspacing
- 16” and larger wheels cannot exceed 5” backspacing
- Not compatible with dual beadlock wheels
- Wheels need to have a center hole of at least 3.25" (82.55mm) or require a 1” wheel spacer
Wheel Requirements
- 14" or larger wheel required
- 14" and 15" wheels cannot exceed 4-1/2" backspacing
- 16" and larger wheels cannot exceed 5" backspacing
- Not compatible with dual beadlock wheels
- Wheels need a center hole of at least 3.25" (82.55 mm), or a 1" wheel spacer is required
Cast vs. Billet Housings
- Cast aluminum: the value choice, built on the same reinforced design
- Billet 6061 aluminum: USA-made and CNC machined, the premium choice for riders who want the best
Both use the same gears, shaft and sealing, so the choice comes down to budget and preference. Either way, you get the same lift, gearing and tire capacity.
Need Help Choosing?
Send us your current tire size, wheel specs and where you ride most, and we'll help you match the right reduction and suspension setup.
What's in the Box
- Portal gear boxes with your choice of housing and reduction
- Hardware and backing plates
- Brake lines
- Instructions
Who It's For and What Pairs Well
For RZR XP 900 and XP 4 900 owners who want more clearance and torque without giving up the factory ride. Combine it with a 3-5" kit from RZR XP 900 lift kits, forward-offset arms from RZR XP 900 suspension parts and a power steering kit to make bigger tires easier to turn.
Installation Notes
The kit includes new brake lines, so you'll need to bleed the brakes after installation. Separate 2-seat and 4-seat instructions are linked below.
- source:
- superatv
- satv_url:
- https://www.superatv.com/polaris-rzr-xp-900-4-inch-portal-gear-lift-g3
- fitment_raw:
- Polaris RZR XP 900 2011-2014; Polaris RZR XP 4 900 2012-2014
- install_pdf:
- https://madmin.superatv.com/amfile/file/download/file/3531/product/13495/
- desc_status:
- rewritten_2026-10-28
- sub_brand:
- GDP
