Polaris Genuine OEM 3900 Chain Tensioner Kit In stock$4099
Quick overview
- Genuine Polaris part The factory 39-120 chain tensioner kit, not an aftermarket copy.
- For the 3900 Sport Listed for the Polaris 3900 Sport pool cleaner.
- Keeps the drive chain tight The tensioner holds slack out of the chain that drives the wheels, which is what keeps the cleaner tracking its pattern.
- Sold as a kit Supplied as the tensioner kit rather than as loose pieces.
- Check it during a rebuild Chain tension is one of the first things to go on a high hour cleaner, so it is worth inspecting whenever the belly is open.
- Look for 393-121 The product data notes 393-121 molded into the sprocket, which helps confirm the part.
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Product details
This is the genuine Polaris chain tensioner kit, part number 39-120, for the 3900 Sport pool cleaner.
What the tensioner does
The 3900 drives its wheels through a chain, and the tensioner keeps the slack out of that chain. Once it wears, the chain can skip a tooth under load. The cleaner then loses drive on one side, wanders away from its pattern, or gives up on wall climbs it used to manage. Replacing the tensioner is the fix, and it is usually done at the same time as any other drive train work.
Part numbers
The kit is listed as Polaris 39-120, and the product data also notes 393-121 molded into the sprocket. Both numbers are recorded here so you can match whichever one is on the parts you took out.
| Brand | Polaris |
|---|---|
| Manufacturer part number | 39-120 |
| UPC | 738919066922 |
| Type | Chain tensioner kit |
| Fits | Polaris 3900 Sport pool cleaner |
| Molded marking | 393-121 molded into sprocket |
| Part type | Pool cleaner part |
| Shipping weight | 0.05 lb |
| Ships | Parcel |
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