Rebuilding OMC 9915 Lower Unit

[jdkline]

" Hey,
I have come into the p

" Hey,
I have come into the posession of a parts 15 HP motor. I was told that the lower unit on the motor was good, and indeed, it seems that teh gears are in excellent conition, but the shift rod is in terrible shape. It constantly slips out of forward. I am thinking of disassembling the lower unit and replacing said defective shiftrod. Obviously I'm no mechanic, and I was just wondering if someone with just average mechanical skills could do this and if I really need those OMC special tools that the shop manual says I do to get it back together. I was already told that this lower unit does not need to be shimmied. Any comments would be appreciated.
J.D. "

 

[themachinist]

" Suggest you get a repair man

" Suggest you get a repair manual.
What year is your motor? If it is from 1974 to about 1992 the shifting rod should just screw out of the lower unit. However be sure you get all the gunk washed out of the cavity that the rod goes down into, otherwise you may knock residue into the gearcase thru the then open seal.

If you need to take the prop shaft & all the gears out, OMC makes a puller that attaches into the 2 holes of the main housing & these attachment bolts are long enough to allow a top bar to go on top of them & with a center hole that the prop shaft goes thru. The prop nut is then used to pull this internal housing out of the gearcase.
You will also need a wire or something to fish the shifting linkage back in place.
Just remember what sequence & relationship of the parts to each other when reassembling. "

 

[joereeves]

"JD.... I've never seen a

"JD.... I've never seen a engine that would jump out of gear due to a faulty shift rod. That rod screws all the way into the lower unit shift mechanism and that's it, there is no measurement.

Jumping out of gear is due to either having the shift linkage at the powerhead out of adjustment, or the "Shifter Dog" and "Gear Lobes" are worn which is the usual case.

Joe

"

 

[sparky]

The shop manual calls for a s

The shop manual calls for a special tool to install the shift cradle( wire attached to it). If you turn the unit upside down while installing the shift cradle gravity does the job each and every time.Done it many times.