Replacing drive plate or friction disc on Craftsman 9HP snowblower.
Snowblower Repair:

Replacing The Drive Plate or Friction Disc
On A Craftsman or MTD Snowblower

Optional Extra Step When Replacing Friction Wheel "Rubber"

 

In This Article:

The friction wheel and drive belt are removed. The wheel shafts and lower shafts are removed. The friction disc bracket is removed and the disc is unbolted with an impact wrench.

Related Articles:

Skill Level: 3-4 (Intermediate to Advanced) Time Taken: About 3 Hours

By Bruce W. Maki, Editor

Start:

Earlier, I had removed the friction wheel to replace the worn out rubber friction material.

Since the drive plate had grooves worn into it, I figured it should be replaced. I was concerned that the grooves might cause rapid wear on the new friction material.

The drive plate (also called a friction disc) isn't cheap. Sears Parts division charges around 60 bucks, and MTD sells it for a couple of dollars less. I bought a new drive plate at SuperXPower.com for $51.38.

Removing friction wheel from Craftsman or MTD snowblower transmission.

Note: In these pictures, the snowblower is tipped on its front to allow access to the underside.

Drive plate and return spring on Craftsman snowblower.

Once the friction wheel was removed, the drive plate (1) was accessible.

Note the return spring (2) on the lower-right. I unhooked this spring from the bracket.

 

In order to remove the drive plate, I first had to remove the belt that powers it.

I removed the plastic belt cover on top of the snowblower to expose the pulleys on the output shaft of the engine.

Drive belt pulleys at top of Craftsman snowblower.

 

Moving idler pulley aside to remove belt for traction drive unit. I pulled the idler pulley away from the belt...

 

...then I slipped the belt off the drive pulley. Belt being removed from pulley on Craftsman or MTD snowblower.

 

Removing belt from drive plate, Craftsman snowblower. I removed the belt at the bottom of the drive plate.

 

Removing The Drive Plate And Bracket:

The bracket pivots slightly on a shaft. The shaft protrudes through each side of the drive unit housing.

One end of the shaft (red arrow) has a retaining pin and washer. (This is the right-hand side of the snowblower.)

Location of pivoting drive plate bracket on 1999 Craftsman snowblower.

 

I removed the cotter pin from the end of the shaft. Removing cotter pin from pivot shaft for drive plate, Craftsman snowblower.

 

Removing small bracket to expose end of pivoting shaft.

At the other end of the pivoting shaft, I removed this small plate, held on by 2 bolts.

Caution: This plate holds a small plastic pulley that is used for the auger clutch cable.

 

That allowed the drive plate and bracket to almost slide out. BUT... the bracket hit the lower driveshaft. I realized that I needed to remove the lower driveshaft (which is used for the steering mechanism). Removing drive plate from Craftsman or MTD snowblower.

 

Removing axle shafts from Craftsman snowblower.

I removed the pins that held the left and right axle shafts to the intermediate axle shaft (red arrow).

Then I pulled each shaft out of the snowblower. There are four large thin washers (one on each side of each chain sprocket) that can fall out when the shafts are removed.

The axle shafts need to be removed so the chain sprockets can be dropped down and the chains slipped off the small sprockets on the lower (steering) shaft.

The right-hand steering clutch cover plate needs to be removed. The left side has already been removed to replace the friction wheel.

The steering shaft can be slipped out either side of the housing. The chains need to be lifted up so they can pass through the holes in the housing.

With all of the shafts removed, I was able to tilt the drive plate bracket so it could be removed. Drive plate being removed after drive shafts are removed.

 

Back view of bracket holding rotating drive plate on Craftsman or MTD snowblower.

The back of the drive plate bracket.

The drive plate is secured by a nut with a 9/16" hex.

 

The shaft (which is attached to the bearing behind the drive plate) has a slot in the end to hold the shaft during assembly.

Removing this nut was the trickiest part of the job.

Slot in end of shaft for drive plate.

 

Using impact wrench and screwdriver bit to remove nut on shaft.

I held the nut with a 9/16" box-end wrench, while using a pneumatic impact wrench with a flat screwdriver bit.

This didn't work on the first attempt... the screwdriver bit kept jumping out of the slot on the end of the shaft. I heated the nut with an ordinary propane torch, then I sprayed it with penetrating oil. I tried the impact wrench again (set to rotate forward) and it worked. Whew! I was kinda worried for a minute.

Without an impact wrench, the only way to remove this nut would be to hold the shaft with some sort of long pry bar bent to a 90 degree angle, and with a flat screwdriver tip fashioned on the end. This job might require making your own tool, which could be done by bending a large flat screwdriver (with a torch) or grinding a piece of 1/8" steel bar stock so there is a slight "L" shape on the end to fit into the screwdriver slot on the shaft.

 

With the nut removed, the drive plate could be separated from the bracket (the green piece).

Nut, bracket and drive plate.

 

New and old drive plates for Craftsman or MTD snowblower. The old drive plate is on the right. Note the circular pattern on the metal face... these are grooves carved into the plate from rubbing against the metal part of the friction wheel.

Next, I installed the new drive plate on the bracket. I just held the shaft with a big flat screwdriver while I tightened the nut with the 9/16" wrench. I think the washer under the nut has a cup-shape (a Belleville washer), because the nut became fairly tight for at least two full turns before it got really tight. Then I placed the bracket back inside the snowblower.

 

TIP:

This is a really good time to replace the traction drive belt. That belt needs to be removed for this repair anyway.

This might be a good opportunity to replace the 2 auger belts, which appear to be easy to reach when the drive plate is removed. (I did NOT replace these belts... they were still in good condition.)

The owner's manual mentions separating the front and rear sections of the snowblower body to reach the auger belts. While I have not done this task, it looks kinda tricky. If you replace them, make sure the auger belts are routed properly under the various pulleys.

 

I re-installed the steering shaft, the two axle shafts and the two outer chains and sprockets.

Note: This is an opportunity to apply some white lithium grease to all the bushings, some of which are shown by the red arrows. The joint between each gear and the intermediate axle shaft is a spot that requires some grease, since the gears can slip relative to the intermediate shaft when the snowblower is turning.

Then I slid the hex shaft back in place, as shown in the article about replacing the friction wheel.

Installing hex shaft and friction wheel, and grease lubrication points on Craftsman snowblower.

 

Plastic cover over drive belts on Craftsman or MTD snowblower.

After replacing the wheels and the bottom cover panel, I tipped the snowblower upright and replaced the black plastic cover (arrow) over the drive belts.

Then the snowblower was ready to use.

 

More Info:

Tools Used:

  • Basic Mechanic's Tools
  • Sockets: 3/8"
  • Wrenches: 9/16" Box-End
  • Needle-Nose Pliers
  • Propane Torch
  • Impact Wrench With Flat-Tip Screwdriver Socket

Materials Used:

  • Friction Disc Assembly, MTD Part No. 956-0012A
  • Penetrating Oil
  • White Lithium Grease
  • Brake Parts Cleaner

Related Articles:

Web Links - Parts Sources:

 

 

 
 
 
 
 
 
 
 

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© Copyright 2011 Maki Media Group LLC

Written February 8, 2011