TB30R drive belt keeps snapping

jmandawg

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Rivets

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First of all the drive belts on these units must be replaced as a pair, changing one can result in the problem you are having. Second for a belt to look like that after one cut tells me it is of poor quality, ie. knock off. Third did you check each pulley to make sure they are not worn or bearings bad? Fourth did you check to see if the shive, (center) pulley of the variable speed assembly is moving freely? Fifth when you installed that belt did you loosen the variable speed assembly, install the belt and retighten the assembly? Sixth are you sure the belt is routed properly and guides are in the right location? Each and everyone of these conditions can contribute to a belts short life.
 

StarTech

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I see the problem. You are using an aftermarket belt. They simply are the wrong belts for MTDs. They have the wrong profiles. It looks like it a standard 5/8" belt height which is thicker than the MTD belt so it rubbing where it should be. I believe if you get a MTD belt you problems will go away.

BTW MTD mowers are very picky as to which belts that will work but the aftermarket vendors don't care as long they sell you a will fit belt.
 
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jmandawg

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Thanks guys. That makes sense because i actually had to remove the pulley to get the belt into the guide in picture #2. I would assume the correct belt would just slip in. I will order the OEM belt, thanks!
 

StarTech

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Not not even the correct belt will just slip on. There is a belt retainer involved and it job is prevent the belt from coming off.
 

jmandawg

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Thanks. I bought both belts at a local repair shop, and they seem to be holding up well so far.

The problem now is the mower won't move in speeds 1-3, but speeds 4-6 work fine.

Is there some kind of adjustment that needs to be done?
 

bertsmobile1

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Starting from the original problem.
Nowhere in the description does it state that the belt is a kevlar ( Aramid fiber ) belt which it should be .Looks very much like a standard rubber belt and the price suggest the same.
So a word to the warning . IT is OEM brand belts for these or belts from a REAL MOWER SHOP some shyster has just sold you $ 2 belt for $ 9 .

Now for the second.
The system works by the difference in belt tension between the top & bottom belts.
To go slow, the top belt has to be tighter than the bottom belt thus forcing the sliding sheave down so the bottom belt is running on a larger effective diameter .
Thus either the spring on the top belt is not pulling tight enough or some thing is stopping the bottom belt getting loose enough .
Double check the position of all of the springs.
 

jmandawg

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So i didn't take a picture of the rear spring before i took it apart. Is this the correct connection location?

It doesn't seem right because it rubs on the bar below it.
 

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