Main Drive belt replacement on a MTD garden tractor

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  #1  
Old 05-18-09, 10:05 PM
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Main Drive belt replacement on a MTD garden tractor

I have a MTD 20/46" Yard Machine bought 4-22-1999
Mod 14AU845H088 SN 18119850026
With a Briggs & Stratton Mod 407777 Type 0124E1 Code 990187YC [20hp i/c 46" 14 speed]
Main Drive belt .PN 754-0280.or. GATES PN 6605BR [21/32" x 45-3/4" 17mmx1163mm]
How do I release enough tension to get the new drive belt on?
I have the plate off that has the belt guard/shields on it.
Can I loosen the pulley on the variable speed shaft; or, take the engine bolts loose to slide it back to gain some slack? Any tricks to getting the new V-belt on? Thanks HH
 
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  #2  
Old 05-18-09, 10:19 PM
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There is no adjustment. When the belt starts giving problems, you have to replace it. You should replace both with exact replacements from MTD. (they are special made with a custon pitch and length that is not duplicated by standard belts to operate the varidrive setup properly). It's a tricky job to replace the belts. I find it best to remove the clip holding the varidrive pulley on and lifting it enough to get the belts off it first.
 
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Old 05-18-09, 11:05 PM
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Thanks Cheese. The problem is ... the old v-belt wore out and broke into. No problem getting the old one off. Just getting the new one on.
HH
 
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Old 05-18-09, 11:15 PM
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Same way...over the engine pulley first, then with the varidrive pulley loose, put it on it, then put the pulley back in place.
 
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Old 05-21-09, 09:10 AM
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Thanks for your help. I have been on grandkid duty and haven't been able to get back out to the garage to work on the mower. I'll let you know what I do to fix it in time
 
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Old 05-28-09, 06:47 PM
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Well I have read several posts about going with factory equipment belts but didn't listen. I bought a Gates Belt PN 6447BR 21/32" x 52 -7/8" and put it on. I mowed about a third acre and the belt is mushy and the second you push the clutch in, it drops off the variable speed pully. Yes it was half the price of the genuine MTD and Yes I now have ordered the real thing.I ordered from BuyMTDOnline Landing Page pn 954-0280A. I will post another update when it comes in and I get it installed. Till then ... the grass is growing!
hh
 
  #7  
Old 06-05-09, 08:56 PM
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I received the new MTD main drive belt and got it on but I noticed another related problem on this MTD Yard Machine Mod 14AU845H088 SN 18119850026
With a Briggs & Stratton Mod 407777 Type 0124E1 Code 990187YC [20hp i/c 46" 14 speed]

How do I get the engine pulley IPB#107 off to replace it? I have removed the bolt holding it on and tried to use a hammer to jar it loose but itís not budging.
Is there a special tool/puller?
Do I need to apply heat.
The top pulley on this engine pulley assembly has separated and the top half is loose. I can raise it up and turn it around on the shaft but the rest of the assembly is stuck on the engine shaft. Thanks for your input! hh
 
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Old 06-05-09, 11:07 PM
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The pulley should just slide off. Sometimes it's not that easy. I have had some come off with prying and tapping with a hammer. Some took more aggressive persuasion, and one or two had to be cut off.
 
  #9  
Old 06-17-09, 10:57 PM
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I finally managed to get the old main drive pulley off and the new one on. The new MTD belt on, and everything back in place. I started it up and backed it out of the garage. I mowed two rounds and the belt was smoking badly. I stopped the mower and inspected the belt. The new MTD belt did same thing as the Gates. The inner part of the "v" is worn off. Can this be caused by the [IPB#15] Variable Speed Pulley? Has anyone experienced anything like this? Tell me how to post pictures to this site and I will. Thanks. HH
 
  #10  
Old 06-18-09, 10:32 PM
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The inner flat edge of the belt is rubbing off? If so, it sounds like it's running over a belt guide or rubbing on a part somewhere...routed incorrectly. The varidrive pulley could possibly cause this if the belt was riding all the way down in the pulley and the pulley was locked up.
 
  #11  
Old 07-21-09, 09:41 AM
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Thanks Cheese for your input. I have taken the variable speed shaft out of the mower. What Parts of this assembly should rotate?
hh
 
  #12  
Old 07-23-09, 01:09 AM
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The center sheave should spin independently of the rest of the assembly.
 
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