Matched front and rear portal axle conversion

Installation notes

• One 40128 kit covers the front/rear pair. Build both axles from the two bags using the factory instructions; do not buy two complete kits or count every included bearing and gear as an additional purchase.
• Retain the compatible original chassis links, CMS servo/panhard and steering linkage, shocks, center shafts and serviceable chassis fasteners. Transfer only after checking link/shaft clearance and full steering/articulation on the installed build.
• Use the supplied front portal steering plates and the rear adjustable-toe link arrangement. The rear sheet specifies a 12mm exposed gap for its rod-end link; this is not total link length. A rear steering servo/radio conversion is a separate unprepared route.
• The standard kit uses 30T/8T ring/pinion and 20T/15T portal gears on each axle. This increases axle reduction from 3.75:1 to 5:1, derived from those tooth counts. Do not retain the original straight-axle calculator ratio after the physical conversion.
• The factory sheet recommends a 78T spur. The alternate route includes 9652 78T48P for the retained Stealth X only. A recommendation is not an extra requirement on both routes; the existing pinion, motor and load still need checking.
• Use suitable axle grease during assembly. Check body/wheel clearance, steering endpoints, caster, rear toe and full center-shaft engagement. Keep original supported power limits; no durability or measured speed improvement is claimed.
• Do not add this as an absent-feature upgrade to Ecto Portal or Trailwalker Portal Plus. Mixing one portal with one straight axle is excluded until front/rear rollout and drivetrain ratios are deliberately matched.

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