Mercury 15 EFI FourStroke, Service Manual

Page: 341 / 406

NOTICE
Installing the gear housing to the powerhead without adequately cleaning the top of the driveshaft can result in severe
product damage. Any lubricant trapped in the space between the driveshaft and the crankshaft prevent the two from properly
engaging. Always clean the top of the driveshaft before installing the gear housing.
Tube Ref No. Description Where Used Part No.
95
2-4-C with PTFE Driveshaft splines 92-802859A 1
5. Guide the gear housing into the driveshaft housing. Rotate the gearcase slightly, as necessary, to engage the driveshaft
with the crankshaft.
6. Secure the gearcase with four screws and washers. Tighten the screws to the specified torque.
62827
Gearcase screws (two per side)
Description Nm lb‑in. lb‑ft
Gearcase screws 24.0 – 17.7
7. Thread the jam nut onto the lower shift shaft until it stops turning.
8. Maintain alignment of the upper and lower shift shafts while threading the coupler at least five turns onto the lower shift
shaft.
IMPORTANT: Take care to not rotate the lower shift shaft. Doing so will damage components within the gearcase.
9. Use two wrenches to lock the jam nut against the coupler.
a - Upper vertical shift shaft
b - Wrench on coupler
c - Wrench on jam nut
10. Check the shift operation as follows:
• Place the shift lever in forward. The gear housing should ratchet when the propeller shaft is turned clockwise and
resistance should be felt when the propeller is turned counterclockwise.
• Place the shift lever in neutral. Resistance should not be felt when the propeller shaft is rotated in either direction.
• Place the shift lever in reverse. Resistance should be felt when the propeller shaft is rotated in either direction.
• If the shift operation is not as described, check the coupler installation procedure. If the coupler installation procedure
is correct, the gearcase is not properly assembled or internal parts are excessively worn and must be replaced.
a
c
b
64463
Gear Housing (2.15:1)
Page 6A-40 © 2018 Mercury Marine 90-8M0125265 eng NOVEMBER 2017