SERVICE BULLETIN
M1650

2025-01-23

M1650: MILWAUKEE EIGHT AND TWIN CAM CAMSHAFT DRIVE GEAR RETENTION
KIT CHANGES
2009-2016: Trike Twin Cam models

Reason for Revision

2018 and later: Softail Milwaukee-Eight models

Table 1

2017 and later: CVO, Police, Touring and Trike Milwaukee-Eight
models

Table 1. Document History
Date
Rev
Revision (Rev) Description
2025-01-23 - Initial release

Markets Affected
All markets affected.

Purpose for Service Bulletin

Part Numbers

This bulletin informs dealers that changes have been made to
the Camshaft Drive Gear Retention Kit and service procedures
for the Milwaukee-Eight and Twin Cam applications.

Table 2
Table 2. Part Numbers

In an effort to increase the clamp load of the camshaft drive
sprocket bolted joint and prevent the drive bolt from loosening
in high lift camshaft applications, the following changes have
been made:
a. The camshaft drive bolt final torque has been increased to
40 ft-lbs (54 N·m) for all Milwaukee-Eight and certain Twin
Cams models. See Vehicles Affected. This increase in
torque will make the bolt a one time use application.
Never re-use a camshaft drive bolt for service after
tightening to the increased specification. See service
manual for updated procedure.
b. A new camshaft drive gear retention kit (Part No. 91800088)
has been created. This new kit is compatible with all
Milwaukee-Eight and Twin Cam engines using Parts and
Accessories (P&A) camshaft and Original Equipment (OE)
camshaft applications. See Instruction sheet for specific
fitment on Twin Cam OE camshaft applications. The new kit
utilizes friction washers to prevent unwanted rotation of
components in the drive sprocket bolted joint under stress.
The use of liquid threadlocker on the threads of the bolt and
pre-lube to the head of the bolt flange and outside of the
washer help the bolt reach full stretch when tightening.

NOTE
Engines produced at all Harley-Davidson Motor Company
(HDMC) plants will not come with the new kits installed. They
will continue to be produced with (Part No. 25566-06).

Current Part
No.

Item Description

New Part No.

25566-06

Camshaft Drive Gear
Retention Kit

91800088

Required Dealer Action
Table 3.
Action
Required
NO
YES

Resolution
Non-Actionable:
This is for informational purposes only or a
technical tip.

Follow new service manual procedures and kit instruction sheet
for best results.
• Use new Camshaft Drive Retention Kit (Part No. 91800088)
in ALL P&A camshaft applications.
• Use existing stock of (Part No. 25566-06) on all OE Twin
Cam camshaft applications.

Dealer Inventory Instructions
Use Camshaft Drive Retention Kit (Part No. 25566-06) on OE
Twin Cam camshaft applications.

Vehicles Affected
2006-2017: Dyna Twin Cam models
2007-2017: Softail Twin Cam models
2007-2016: CVO, Police and Touring Twin Cam models

NOTE
In the interest of preserving customer safety and satisfaction, always check for outstanding recalls whenever any motorcycle is brought into your dealership for either maintenance or service.
ROUTING

INITIAL HERE

SERVICE
MANAGER

SALES MANAGER PARTS MANAGER

WARRANTY
PROCESS
MANAGER

LEAD TECHNICIAN TECHNICIAN NO. 1 TECHNICIAN NO. 2 TECHNICIAN NO. 3 RETURN THIS TO

Supplemental Procedure Video
WARNING
Always review the appropriate service procedure prior to
performing it. This video is intended to supplement, not
replace, documented service procedures. Attempting
service procedures without the proper training, tools,
equipment, and manuals could result in death or injury to
you or others. This could also damage the motorcycle or
cause the motorcycle to operate improperly. (10406a)
This video is a supplement of the procedure covered in the
document. This video can only be viewed through Service
Information Portal (SIP).
1436457

Video 1. Camshaft Drive Gear Retention Kit

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M1650