*Pictures may differ from the actual product.

Automatic Primary Chain Tension Adjuster




39990-01, 40063-05A

New product


Original Equipment on '06-later Dyna® and '07-later Softail® and Touring models, this Automatic Primary Chain Adjuster eliminates the need to manually adjust the primary chain tension at traditional service intervals.

  • Requires separate purchase of model-specific primary gasket and seals

More details


£ 119.24 tax incl.

Available to backorder Due to logistics in the USA, we are currently experiencing extended shipping times on Harley-Davidson® backordered products.

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Product Information

IN THE BOXChain tensioner and all necessary installation hardware
WARRANTY1 year limited warranty - See Customer Service section for details

More info

  • These Screamin' Eagle® products are 50-state street-legal for sale and use on all vehicles, including those that are pollution controlled. Complies with the requirements of 40 CFR Part 86, subparts E and F.

Bike Fitment

Fits '85-'06 Evolution® 1340 (except '85-'88 Softail®) and Twin Cam powertrain. Requires separate purchase of model-specific primary gasket and seals.

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*Fitment details are provided in good faith and do not guarantee suitability for your bike. If in any doubt please contact our parts department before ordering.