Heavy Duty Stock Clutch Spring

Part Number 37951-98




Assists in increasing capacity of stock clutch.


Fits ’99-'17 Twin Cam-equipped models and ’98-’99 Evolution® 1340-equipped models. Will not fit '16-'17 FXDLS, FLSS, FLSTFBS and FXSE or '13-'16 CVO™ Touring models with hydraulic actuated clutch, or ’15-'16 FLHTCUL and FLHTKL, ’14-'16 Touring and Trike models equipped with Screamin’ Eagle® A&S Clutch Kit P/N 37000026.

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  • Model
  • These Screamin' Eagle® products are 50-State U.S. EPA compliant for sale and use on all applicable vehicles, including those that are pollution controlled. See Genuine Motor Parts and Accessories or Screamin' Eagle Accessories catalog for fitment information. Screamin' Eagle Performance products are intended for the experienced rider only.
  • Warranty

    1 year limited warranty – Go to for full details
  • Requires ECM Calibration

  • Sold in Unit

  • In The Box

    Clutch spring only
Heavy Duty Stock Clutch Spring is rated 4.7 out of 5 by 3.
Rated 4 out of 5 by from Gorilla hand I coupled this spring with the performance clutch to hold with my 103" dynoed at the rear wheel 96 horse and 106 lbs tourque. The less you use the clutch, the more you will like it. It works as advertised, but the pull is heavy. Expecting this, I still rate it four stars for no slip as run with the performance clutch.
Date published: 2017-07-02
Rated 5 out of 5 by from Good upgrade This was part of an upgrade I did that included cams and pushrods. Made a big difference in the way the clutch grabs.
Date published: 2015-09-09
Rated 5 out of 5 by from Heavy Duty clutch diaphram spring I paired this diaphram spring with a new clutch cable and a Barnett Extra Plate clutch kit and came up with a winner. My 2009 Super Glide has a much improved and more positive feel on clutch are either at a full stop or moving - there is very little play in take off and I would highly recommend this particular item for any Dyna owner.
Date published: 2015-03-18
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  • clientName_harleydavidson

Which heavy duty clutch spring do I need?

I have a 2015 road glide special with a hydraulic clutch. I want to upgrade the clutch spring and give me more holding power when I replace the stock clutch plates. What part number do I need because the discription for what I'm finding says it will not work with hydraulic clutches.
Asked by: Playle
Hi Playle, Please see your local dealer for support. We are unable to provide you with information that will modify the original clutch. Thanks!
Answered by: RowdyGrl79
Date published: 2016-06-14

Will this work with the narrow primary cover?

I installed a narrow primary cover on my '15 FLHTK. Is this the reason it will not work on the FLHTKL?
Asked by: Buckshot85
Hi Buckshot85, The reason this Heavy Duty Stock Clutch Spring will not work with ’15-later FLHTCUL and FLHTKL models is not due to the narrow primary cover, it is because the FLHTCUL and FLHTKL are equipped with Screamin’ Eagle A&S Clutch Kit P/N 37000026. Thank you for your question.
Answered by: FXS78
Date published: 2016-02-15

do the preformance spring and clutch fit together?

Is this Heavy Duty Stock Clutch Spring-37951-98 a good fit with the SE Performance Cutch Plates 37980-10 for my 2010 Ultra Classic FLHTCU?
Asked by: Johnnymac
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    Prices listed are generally the Manufacturer's Suggested Retail Price (MSRP), excluding taxes and shipping. Prices at local dealerships may vary. All online orders will be fulfilled and shipped by
    Harley-Davidson Motor Company as the agent for the Selling Dealer.