sonnax-black Facebook-color LinkedIn-color maillink printlink r_and_r_only SERVOFIX-logo-web Twitter-color VBFIX-logo-web video-logo-web warranty_only Youtube-color


Extreme strength spline configuration requires use of thrust bearing between forward clutch hub and direct drum that moves support of forward clutch hub from the main shaft to the direct drum/sun gear tube (see instructions Figures 1 & 4).

400, 4L80-E, 4L85-E

Extreme Duty Main Shaft
Part No. 34672-05

View Instructions

Main shaft failure is a common problem in extreme duty 400, 4L80-E and 4L85-E units. OE and aftermarket shafts simply don’t hold up in extreme horsepower applications, leading to spline twist and shaft breakage. Sonnax extreme duty main shaft 34672-05 is manufactured from an exceptionally tough high-strength steel alloy with proprietary heat treatment for unrivaled performance and durability. An advanced torsional design with spline and cross hole refinements make this the most durable 1" main shaft available. Sonnax extreme duty main shaft withstood extensive in-vehicle and lab testing with unbroken results run after run.

  • Top-notch engineering and precision manufacturing deliver unrivaled performance and durability in the 1” stock size
  • Rear spline prevents the rear internal gear journal-end from twisting off by engaging the full internal spline of the gear
  • Extensive in-vehicle and lab testing with unbroken performance

Can be used to replace late 4L80-E and 4L85-E solid shafts, however, check clearance between front of main shaft and rear of input shaft. It may be necessary to remove approximately .060" from front of main shaft or rear of input shaft.

March 29, 2017

Transmission Report: Sonnax Voted Tops for Parts & Tools!

Topics: Transmission Report Newsletters Transmission GM 4T65-E Transmission 4L70-E Transmission 4L60-E Transmission 4L65-E Transmission 4L80-E Transmission

Read Now
  • 34672 05