Following the service manual for my MTD 12/38 Model 400 belt replacements, I have ended up with an extra spring and can't figure where it goes. The spring is 6 inches in overall length and the coiled section is 4 1/2. I think it may go to the idler pulley because it seems to have a hole on the pully wheel. I don't know where the other end should be attatched. All the other springs are in their proper places. I can't find a diagram that shows where this spring might go. The manual has an exploded view of the bottom of the mower but the drawings are so bad I can't tell. Anyone that can help with a little more precise info would be appreciated. I'm stuck in the middle of a repair I can't complete. Information such as, where each end connects and what side of the mower would really be helpful. Thanks

 

If you can post the model and SN of your mower, I or someone may be able to help. I myself would need to look at the IPL for your mower to try and suggest possible locations for your spring.

The Model Number is usually located on a decal underneath the seat.

 

Is there a spring connected to the rear of the deck that stretches all the way under the transmission to a hook that comes down from the left side where the transmission bolts to the frame behind the rear wheel? If not, this may be where your spring came from. MTDs have more springs than any other mowers I think.