Replace friction wheel rubber ring on Craftsman or MTD snowblower.
Snowblower Maintenance And Repair:

Replacing The Friction Wheel Rubber
On A Craftsman Or MTD Snowblower

Fixing A Snowblower That Stops Moving At Minor Obstructions

 

In This Article:

The bottom cover is removed, the left wheel is removed, the left steering clutch is unbolted, and the hex drive shaft is removed. The friction wheel is removed and taken apart to replace the rubber ring.

Related Articles:

Skill Level: 3 (Intermediate) Time Taken: About 2 Hours

By Bruce W. Maki, Editor

Start:

Symptom: The snowblower would stop moving forward when it encountered anything more dense than fluffy powder snow. In some gears the machine would stop more easily than others.

Solution: When I removed the lower cover panel, I discovered lots of rubber shavings, and a worn-out friction wheel. Replacing the rubber friction material solved the problem, but another part needed replacement because I neglected to inspect the friction material and replace it sooner.

 

To work on the drive unit (or "transmission"), the snowblower needs to be tipped on its face.

Gasoline may leak out of the fuel tank when the snowblower is tipped over. Placing a sheet of plastic (in this case a plastic sandwich bag) under the gas cap will prevent fuel from leaking out of the small vent hole in the cap.

I've found that this step is not necessary if the gas tank is less than half full.

Plastic bag under gas cap.

 

Snowblower tipped on front, to service the drive unit or transmission. I tipped the snowblower on it's front. I placed a couple of blocks of wood under the top part of the snowblower housing, so the auger wouldn't hit the uneven floor. (This isn't necessary, just my preference.)

 

I removed six bolts (red arrows) on the bottom cover pan under the snowblower. This required a 3/8" socket. Location of 6 bolts on bottom cover pan, Craftsman or MTD snowblower.

 

Rubber and metal shavings on bottom cover pan, Craftsman snowblower.

When I removed the cover, there were a lot of metal and rubber shavings inside. That's not a good sign.

Rubber shavings would be expected as the friction wheel wears, but metal particles indicate wear on metal portion of the friction wheel, and possibly the drive plate.

 

The drive plate (1) gets pulled against the friction wheel (2) to make the snowblower move forward or backward.

The gearshift simply slides the friction wheel sideways along a hexagonal shaft. In lower speeds, the friction wheel is closer to the center of the constantly-spinning drive plate.

In reverse "gears", the friction wheel is located to the right of the center of the drive plate, causing the friction wheel to turn the opposite direction.

Drive plate and friction wheel inside "transmision" of Craftsman or MTD snowblower.

 

Rubber friction material has extensive wear, and drive plate has grooves, Craftsman snowblower.

Note how the rubber on the friction wheel (1) is worn down flush with the "pulley" it's fastened to. That's not good.

Also, the drive plate (2) has a lot of grooves cut into it, which explains the metal shavings I found earlier. I will need to replace this part.

Arrow 3 points to the metal bracket that holds the drive plate.

 

Another, separate problem: The hook on the spring on the end of the drive clutch cable broke a couple of weeks earlier. I bent the broken end into a hook (I had to heat the metal with a propane torch) but the hook kept bending and letting go.

(Read more about replacing the broken hook.)

This hook is connected to a hole (red arrow) in the pivoting bracket that contains the drive plate, and when the drive clutch handle is engaged (i.e. pushed down), the drive plate is pushed into the friction wheel, causing the axle to turn.

Drive clutch cable disconnected from broken hook on end of spring.

 

Removing drive wheel on Craftsman or MTD snowblower. I removed this "click pin" (retainer pin) from the larger metal pin on the end of the shaft at the left wheel.

 

I removed the left wheel and set it aside. Craftsman snowblower with left wheel removed to reach steering clutch cover plate.

 

Location of bolts on cover plate  for left-hand steering clutch, Craftsman snowblower.

I removed four bolts (red arrows) on the left-hand drive cover, using a 3/8" deep-well socket.

 

I carefully pulled off the left-hand drive cover.

There is a hex-shaped washer and washer behind it that fell off when I removed the cover (red arrow).

Removing the left-side steering clutch cover plate, MTD snow blower.

 

Sliding hex shaft from left side of Craftsman or MTD snowblower.

I pulled the hex shaft out of the left side.

A chain sprocket and spacer fell out of the right-hand side when I removed the shaft. The bearing fell out too.

 

This is the sprocket and spacer that belong on the right-hand side (shown in the proper orientation). Chain sprocket and spacer bushing on end of hex shaft, Craftsman snowblower.

 

Removing friction wheel from Craftsman snowblower. I removed the friction wheel once the shaft had been removed.

 

At this point the drive plate (red arrow) is accessible. A belt connects the drive plate to the output shaft of the engine.

If the friction wheel rubber never gets badly worn, the drive plate should never need replacing (unless the bearing goes bad). The drive plate on my snowblower had developed some deep grooves, so I ordered a replacement along with the friction wheel rubber.

Read about Replacing The Drive Plate.

Drive plate after the friction wheel has been removed.

 

Replacing The Rubber Friction Material:

Friction wheel and bearing, Craftsman or MTD snowblower.

There are 6 bolts holding the two halves of the friction wheel together, 3 on each side.

The bolts on the side with the bearing are kinda difficult to reach.

 

The bolts on this side are easy to reach. Back side of friction wheel.

 

Hex shaft placed in vise to hold friction wheel while bolts are removed.

It seemed almost impossible to hold the friction wheel while turning the bolts, so I placed the hex shaft in a vise and placed the friction wheel on the shaft. Then I used a 3/8" offset-end wrench to remove the bolts on the bearing side. The bolts on the other side can be removed with a socket or regular wrench.

NOTE: I used two small blocks of wood to hold the hex shaft in the vise, to prevent the shaft from being marked or gouged. Since the friction wheel slides back and forth along this shaft, it needs to be keep smooth and free of nicks and burrs.

If an offset box-end wrench is not available, a regular box-end wrench may work.

Then I just separated the two halves of the wheel and removed the old friction rubber. Old friction wheel rubber removed from 2-part metal assembly.

 

New MTD friction wheel rubber, part number 935-0234B.

The new friction rubber (MTD part no. 935-0243B).

This part has an outside diameter of 4.875" (4-7/8 inches).

 

The new friction rubber was about 1/8" thicker than the old, worn-out one. New friction rubber compared to old worn-out rubber.

 

MTD or Craftsman snowblower friction wheel with new rubber ring.

I installed the new friction rubber on the wheel. First I cleaned the inner surfaces of the metal halves with brake parts cleaner. I placed the rubber "donut" on the metal pulley and assembled the two halves, making sure the rubber was placed so it protruded uniformly.

I placed the the friction wheel on the hex shaft (still in the vise) and tightened the 6 bolts uniformly, turning each a little bit at a time until they were all tight.

 

Installing The Friction Wheel:

Before installing the friction wheel, I cleaned the drive plate with a paper towel and automotive brake parts cleaner, to remove any traces of grease and oil.

Installing new friction wheel in Craftsman or MTD snowblower.

Installing the friction wheel was a reversal of the procedure to remove it, with one exception. There is a hole on the bearing body that needs to slip over a "nub" on the shift linkage... while the hex shaft is inserted from the left side.

Then the small chain sprocket needs to be placed on the right-hand end of the shaft, along with the spacer bushing. The end of the shaft then goes into a bearing which is held in the side of the snowblower housing.

 

The completed assembly, with a new drive plate and new friction wheel rubber. Gear box or transmission in Craftsman 9HP 28 inch snowblower.

Next I replaced the bottom cover and tipped the snowblower back on its wheels. I let the snowblower sit for a few minutes so the oil would settle back into the engine sump. When I ran the snowblower, it worked as good as new. Now the snowblower will actually move in first and second gear. And it chews through snowbanks like nobody's business.

More Info:

Tools Used:

  • Basic Mechanic's Tools
  • Sockets: 3/8"
  • Wrenches: 3/8" Offset Box-End
  • Pliers
  • Bench Vise

Materials Used:

  • Friction Wheel Rubber, MTD Part No. 935-0243B
  • Brake Parts Cleaner
  • Chain and Cable Lube
  • Lithium Grease

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© Copyright 2011 Maki Media Group LLC

Written February 8, 2011