Tip & How-To about Stairmaster 4000PT Stepper

Alternator Belt Replacement for Stairmaster 4000PT Stepper

Stairmaster Stepper 4000PT Alternator Belt Replacement WARNING: The belts must be properly tensioned. A belt that is too loose will cause slow and sluggish operation. A belt that is too tight will cause excessive noise and belt wear.

  1. Remove side covers.
  2. Loosen the adjustment screw that mounts the alternator to the alternator brace and the pivot adjusting bolt that mounts the alternator to the frame.
  3. Pivot the alternator down and remove the belt.
  4. Make sure the is centered on the pulleys during installation.
  5. Pivot the alternator up or down as necessary to allow 1/4" (0.6 cm) of belt deflection with fingertop pressure at the midpoint between the two pulleys.
  6. Tighten the alternator adjustment bolt. Verify 1/4" (0.6) deflection in the belt.
  7. Reinstall the covers

How to Replace Alternator Belt on Stairmaster 4000PT Stepper

Posted by on

Stairmaster 4000PT Stepper Logo

Related Topics:

Related Questions:

1 Answer

belt continues to slip off

Replacement Parts for Fitness Exercise Equipment at SPORTSMITH

This video covers the installation and adjustment of the Eccentric Hub Assembly for the Stairmaster 4400PT/CL and 4600PT/CL Steppers.
The video begins with the Eccentric Hub Assembly removed from the unit. If you need help removing the Eccentric Hub Assembly from your stepper, please see our video about the Eccentric Hub Assembly Removal.
Tools Needed: Socket Wrench, 7/16" Socket, Adjustable Wrench or 7/16" Wrench
  • Begin by placing your HTD toothed belt around its pulleys. This allows you to set the proper belt tension before mounting the Eccentric Hub Assembly to the frame. The "egg" shape of the Eccentric Hub allows for adjustment of the belt tension. Rotate the hub counter clockwise to tension the belt. Proper belt tension allows about ΒΌ" of play.
  • Line up the 4 bolts through the Eccentric Hub Assembly and the frame. Be sure to place the bolts facing the same direction as noted from removal of the old Eccentric Hub Assembly.
  • Once all the bolts are aligned, retighten them to the frame using the socket wrench with socket on one side and the other wrench on the opposite side.
  • Reinstall the poly-v alternator belt.
  • The Eccentric Hub Assembly installation and adjustment is now complete.

Stairmaster 4400 4600 Eccentric Hub Installation Adjustment

Sep 30, 2013 | Stairmaster 4400 PT Stair Stepper

Not finding what you are looking for?

421 people viewed this tip

Ask a Question

Usually answered in minutes!

Top Stairmaster Exercise & Fitness Experts

Sportsmith LLC
Sportsmith LLC

Level 3 Expert

918 Answers

Matt Olenzek
Matt Olenzek

Level 2 Expert

297 Answers


Level 3 Expert

5687 Answers

Are you a Stairmaster Exercise and Fitnes Expert? Answer questions, earn points and help others

Answer questions