Small Engines (Lawn Mowers, etc.): Older Craftsman Trac Drive Snowblower, friction wheel, correct tension

Question
I have a Craftsman Snow blower with traction drive (tracks not wheels) early to mid 1980s.  Model number 536884900, 8 speed (6 forward 2 reverse), 8 HP engine #143786032 (Sears # 90006291).  My problem is with the drive system, it just started this winter.  I have reverse and the first two forward speeds though sluggish and do not have the 4 other forward speeds.  The tracs are sluggish or don’t even move.  I’ve replaced both belts and installed a new friction wheel and the problem still exists.  If I place blocks under the snow blower and raise the tracs off the ground it seems they move correctly, when I have the snow blower down on the ground a again I have the same problem.  Do you have any suggestions?

Answer
Hello Steve:

>>Does the Engine Bog Down when the Drive is Engaged?
>>Are you Sure the Tension Spring/s Still have the Correct Tension?
>>Did you Replace the Drive Disc and the Driven Disc? These should be Replaced Together if the Drive Disc has Slight Indentations Worn in it by the Rubber on the Driven Disc.
>>A Worn Drive Disc will Cause this Problem, as will the Spring Tension being too Weak.
>>To View a Breakdown of this Unit Go to this Site Addy, http://www.searspartsdirect.com/partsdirect/index.action?sid=PSHx20080114x00001 and Enter the Model Numbers (536884900 for the Unit and 143786032 for the Engine) and Click Search. From this Page you can View Diagrams and Parts Lists for you Equipment Using the "View Sub Components" Section Near the Bottom Left.
>>From your Description it Sounds like the Drive Disc or the Spring Tension.
>>Please, Do Not Hesitate, If you Hit a Snag, if I Missed Something or this Does Not Correct the Problem, I am Here if You Require More Assistance. Hope this Helps. Let me Know What Happens, Please. May the All Mighty Bless You and Yours. Thanks.

Good Luck

Respectfully

John

>>PS: I am Allowed to Answer 10 Questions a Day. If you See I am Maxxed Out, then Try Submitting your Question at or Just After 8pm EST (US). My New Day Starts then. Comments and Ratings are Greatly Appreciated. Thanks.

Respectfully

John