NOTE - Changing
camshafts in Twin Cam 88 engine is different than in previous engines.
Procedure requires use of hydraulic press and special tools. This
installation should be undertaken only by experienced mechanic with access
to Harley-Davidson service manual and all required Harley-Davidson tools
or equivalent. Tightening fasteners to correct specifications with
accurate torque wrench is mandatory.
CAUTION - Incorrect installation can cause
engine damage not
covered under warranty.
For reliable operation, it is
strongly recommends installing Andrews Sprocket Kit #33-4270 along with
the camshafts. This kit is available from S&S and Andrews Products
(773-992-4014), and through most aftermarket retailers.
1. To remove stock pushrods which will not
be reused, remove pushrod cover clips, collapse pushrod covers, place
motorcycle in gear, and rotate engine to place lifters and pushrods for
either cylinder at lowest point on camshaft. Piston for same cylinder will
be at TDC on Compression stroke and pushrods will spin with light finger
CAUTION - Cutting pushrods with saw may
result in metal chips entering
engine and causing extensive engine damage not
covered under warranty.
WARNING - Proceeding without pushrods in
proper position can cause bodily
injury. Cut pushrods with bolt-cutter and remove from engine.
Rotate engine to place pushrods for other
cylinder at lowest point and repeat procedure.
If stock pushrods are to be reused, remove
motorcycle gas tank and top rocker covers. Remove rocker assemblies and
pushrods according to procedure described in Harley-Davidson TC88 Service
2. Remove engine gear cover and gasket. It
is not necessary to remove ignition sensor from cover. Secure lifters with
magnets or tool made from large binder clip spring.
3. Rotate engine to align camshaft timing
4. Remove bolt and washer from 17 tooth
5. Remove bolt and washer from 34 tooth
primary camshaft sprocket.
NOTE - Use H-D Sprocket Locking Tool
#HD42314 to secure sprockets while bolts are removed.
6. Use H-D tool #HD42313 (Cam Chain
Tensioner Unloader) to swing primary cam chain tensioner away from chain.
Secure with retention pin.
7. Working gradually around edge of
sprocket, carefully pry sprockets off cams until loose on shaft. Remove
sprocket/chain assembly and mark chain with arrow to indicate direction of
travel. Chain should be reinstalled in same direction.
8. Remove chain guide. Gradually loosen and
remove four oil pump bolts according to sequence described in "Bottom
End Overhaul" section of H-D Twin Cam 88 Service Manual. Gradually
loosen and remove six support plate bolts according to sequence described
in "Bottom End Overhaul" section of Service Manual.
NOTE- Failure to remove or install bolts
according to correct procedure may result in parts damage not covered
9. Carefully remove cam support plate
assembly from crankcase. Use tool #HD42313 to swing remaining
cam tensioner away from chain. Secure tensioner with second retention pin
inserted through front of support plate. Do not remove pin until support
plate assembly has been reinstalled in engine.
NOTE - It is not necessary to remove oil
pump from engine to complete installation. However, installer must insure
that oil pump o-rings are in good condition and remain in place during
procedure. It is installers responsibility to replace o-rings if
10. Remove screws that secure bearing
retainer to support plate and remove retainer from plate.
11. Carefully support cam support plate on
table of hydraulic press. Using Harley-Davidson camshaft remover/installer
tool #HD-43644, remove stock cams and bearings from support plate.
NOTES: Bearings are usually damaged during
removal and should not be reused. New cam bearings should be obtained from
other source and installed with new cams. Mark secondary cam chain to
indicate direction of travel. Chain should be reinstalled in same
12. Apply assembly lube to outer race of
cam bearing and inner race of support plate. Using tool #HD-43644 and
hydraulic press, install cam bearings in support plate.
13. Apply thin film of assembly lube to
bearing surface of camshafts and inner race of new cam bearings. Support
bearings by inner race. Using tool #HD-43644, press cams into bearings.
14. Align cam timing marks and install
secondary cam chain in original direction of travel. Apply
thin film of assembly lube to outer bearing race and bearing surface of
cam support place and press cam/bearing assemblies into cam support plate.
NOTE: Rear cam has tapped hole in end of
shaft. Front cam is slightly longer than rear cam. Place ram of press over
front cam area of cam installation tool when beginning installation. Place
ram over center of cam installation tool after both cams have engaged
bearings and reached same installation height.
15. Using Loctite #243 (blue) on screw
threads, reinstall bearing retainer and tighten screws to 20-30 in-lbs.
16. Remove cam needle bearings from
crankcase with Harley-Davidson tool #HD42325 and replace with new
bearings. Lubricate with clean engine oil.
17. Apply thin layer of assembly lube to
cam journals and lobe surfaces. Align cams with needle bearings and
carefully slide support plate assembly over crankcase dowels. Apply
Loctite 243 to six support plate screws, install screws, and gradually
tighten to 95 in-lbs. in proper sequence ill.
NOTE - Support plate assembly should slide
into place without resistance. If resistance is encountered, determine
cause before proceeding. Do not force plate assembly!
CAUTION - It
is possible to strip holes for support plate screws when
using maximum 120 in-lb. maximum torque spec recommended by H-D.
Holes stripped are those which pass through alignment dowels,
Positions #1 & #2 in H-D diagram of
Cam Support Plate/Oil Pump Torque Sequence.
18. Apply Loctite 243 to threads and
reinstall four oil pump bolts according to procedure in H-D service
manual: Gently bottom screws, then back out 1/4 turn. Center pump by
rotating engine while snugging screws. Tighten bolts to 90-120 in-lbs. in
19. Instructions from Andrews Products must
be followed to install new A/P sprocket:
One 3/16 drive key and three shims are
supplied in each 34 tooth sprocket kit. Three shims are: .005",
.010", and .020" thick. Andrews Products 34T sprockets are same
length as stock sprockets plus .350" spacer (approximately .690"
length). If stock sprocket used .350" spacer, no shim is required. If
stock spacer is .355", use A/P .005" shim. If stock spacer is
.360", use A/P .010" shim. If stock spacer is .365", use
.005" and .010" A/P shim. If stock spacer is .370", use A/P
.020" shim. Key provided in kit will require light filing for
correct, tight fit in rear cam and sprocket.
CAUTION: Forcing or driving key into
position can damage parts and
result in extensive engine damage not covered under warranty.
Length of key must not interfere with retaining washer.
Shorten key if necessary.
NOTE - Following above procedure should
result in correct sprocket alignment. However, S&S recommends checking
alignment before proceeding. Temporarily install sprockets without chain
and tighten sprocket bolts without Loctite to 25 ft-lbs. Straightedge can
then be placed across sprocket faces and gap (if present) between
straightedge and low sprocket measured with feeler gauge. Gap should be
less than .005 in. If necessary, remove gear and install A/P shims to
correct gap. Remove sprockets after alignment is confirmed and continue
installation as described below.
20. Replace cam chain guide. Rotate cams
until cam marks align. Confirm alignment with straightedge.
21. Insert screwdriver through hole in top
of support plate and carefully pry up on tensioner. Remove retaining pin
from secondary cam chain and confirm position of cam marks.
22. Maintaining original direction of
travel indicated by arrow drawn in Step 7, place primary cam chain over
sprockets. Rotate sprockets until marks align and slide sprockets over
pinion shaft and rear cam.
NOTE - Flat surface on end of pinion shaft
must face up toward center of rear cam for timing marks to align.
23. Apply red Loctite to threads of
sprocket bolt and pinion bolt and a drop of clean 20W-50 engine oil
beneath bolt heads. Use HD sprocket tool to secure sprockets and tighten
bolts to 25 ft-lbs.
24. Carefully remove retaining pin.
25. Install outer cover with new gasket and
tighten bolts to 90-120 in-lbs. in sequence illustrated in Figure 3.
Replace any remaining parts removed to facilitate cam installation. Start
engine and check for leaks.