No reverse, Merc 115 ELPTC 1994 / 115412PD

[Procraft Bob]

After winter storage, first time out I find I have no reverse. Pulled cover, checked shift cable and mechanics and find them to be working properly. Pulled nut off of connector rod (at engine) to disconnect cable from shift arm mechanism. Started engine, (with shift arm disconnected) and manually shifted from neutral to forward, all fine, forward prop, plenty of power. Shifting to reverse, prop turns just a tiny bit, but not with any power. Before I drop lower unit, any further suggestions about any potential "simple" solutions, or further checks? I'm concerned about gear replacement or clutch replacement on my own, and may turn over to a qualified mechanic if that seems to be the likely problem. Any help/suggestions appreciated.

 

[Procraft Bob]

No reverse, Merc 115

Found after recovering my boat from winter storage that I have no reverse gear. All was fine on last use last year. Checked shift cables and they seem to be OK, but I disconnected and manually shifted engine from neutral-forward, then neutral to reverse, both while engine running. Forward seems to work fine, but no reverse. Prop just turns a tiny bit, but with no force or power. Was going to ask you guys for recommendations before dropping lower unit, when I discovered what I think is the trouble. It appears that the prop took a serious blow either putting it in storage or recovering it from storage, and the collar (bolted on) that holds the prop and bearings, and shaft in place has the ears busted. Ouch. After I pursue the matter with my storage unit, I hope to fix the problem on my own. I'm going to need a new collar, but am open to suggestions about gears, bearings, seals, and all else I may need. Or should I consider a new (refurbished) lower unit? And if the latter, any suggestions on where best to obtain? Thanks in advance for help and recommendations. [1115412PD-1994]

 

[racerone]

Is the lower unit in fact the one that was on it in the fall?-----Sounds like maybe there was water in it that froze and popped the rear off.-----Time to ask questions I think.

 

[Procraft Bob]

Racerone: Yes, same lower unit. When I prep for storage in fall, I run engine in driveway, no muffs, with no water in until it blows all water from unit, then I remove fuel line, while running, to run all gas from carburetor's. Then I remove spark plugs and fog cylinders. I've done it this way for 4 years and had no trouble previously. I guess it's possible that it was water freezing, but I'm skeptical. I see a dent in prop too, which could be new, or not. Cannot load my pictures as they are too large files.

 

[Texasmark]

Agree again. R gear is right against the rear bearing that is just in front of the rear prop shaft seal, right at the area where the bolts attach the bearing carrier to the lower unit. Water expanding in the lower unit during the freeze would push out and the weakest link would give. If your bearing carrier is out of place, the clutch dog that encircles the prop shaft and executes the shifting function may not be able to reach the slots/cogs in the R gear and thus you would not have much if any R gear.

If the unit received a blow from outside, there should be damage to the outside of the bearing carrier with paint knocked off and a dent or something to show the externally applied impact area.

 

[Texasmark]

Update: Just read or realized that you had a dent in the prop too. If that occurred in storage then that may be the impact point and it is easy to realize that handling damage can occur. A quick check for water would be the color of your lower unit lube. Merc uses blue-black. If any milky tint to it it's water....but water in the oil wouldn't nick your prop!

 

[racerone]

Did you check for water in the gear oil last fall, yes or no ?

 

[flyingscott]

Was the waterpump replaced recently?

 

[Procraft Bob]

Racerone: Thanks for all of the tips, I'm going to tear into the unit today. I'm afraid, after your notes about water/freezing that may be what happened. The dent in the prop is not large, and I doubt the damage to the flanges could have resulted from a blow to the prop that created the dent in the prop. The damage (break and separation) to the upper bolt flange and lower bolt flange is also almost identical which suggests to me that it may have been from "expansion" from freezing, not a blow from either side or the bottom. The damage is uniform and there is no paint missing from the bearing carrier housing. UGH. I'll check for water in the lower unit lube today. Is it possible that the lube could have frozen? Guess I'd better upgrade my "winterization techniques" going forward, or find a new heated storage for next year.

 

[Texasmark]

Is it possible that the lube could have frozen?

The lube didn't freeze, the water in it did. "When in doubt, pull it out"......check the color of the lube.

That's the problem with cold weather and lower units. They are completely full of oil and as the temperature drops the oil shrinks but the oil up in the leg of the LU...up where the vent holes are, flows down and keeps the gear area full.

With water intrusion, you expand when freezing rather than shrink and there is no place for the the expansion except to put pressure on the containment so either the ass end is going to shoot out or the main LU housing is going to crack. Weak link, carrier bearing housing.

 

[Texasmark]

I responded to your other post on the same problem.

Administrator. Looks like a duplicate post!

 

[Procraft Bob]

Sorry guys, the first time I posted it didn't seem to register and just disappeared.

 

[Procraft Bob]

Tex and Race: Is it reasonable to attempt replacement of the Carrier bearing housing in my garage, or should I head to the Master mechanic? Or should I look for a new lower unit? I'm handy, but not a full-fledged mechanic. I've been waiting for a month for the crappie to start biting, and now I'm "out of the water." Figures

 

[racerone]

Easy project---go for it.----Pressure test this lower unit to look for possible bad seals.

 

[GA_Boater]

All merged into one thread.

 

[Procraft Bob]

Moderator-thanks for the merge.

I think after speaking to a guy at a local marina, I'm going to replace the lower unit. Ouch! Turns our the studs that the carrier bearing mount to are also bent outward in the aluminum casing, as a result of the freezing water. [P.S. The case was full of water when I disassembled, which I'm guessing replaced all lube when I had it in the water for the short trip last week.] I'm afraid that trying to straighten them (the studs) will result in cracking aluminum, and then I'm further up the creek. I also believe that I must have been getting water infiltration into the unit last year which is probably why it froze over the winter. I should have checked the case before storage, (and will from now on), but did not before. Could be just bad seals, or maybe more damage to the housing than I can overcome by replacing the O rings, and carrier bearing assembly.

I would like to "consider" replacing the lower unit myself, but am concerned where best to procure, and then making sure I get the proper lower unit for replacement. It's a 1994 Merc. and I have the serial number, and also the model number. Parts diagram shows that there was a "long-shaft" and "extra-long-shaft" version. I'd hate to get a unit shipped to the house and find I have the wrong one. Any suggestions on who and where to obtain, and how best to insure I get proper unit? Thanks again fellows. Your advice is top notch and I appreciate you dealing with this Cadet.

 

[racerone]

Well , many folks learn about maintaining their motor the hard way and that is through an empty wallet.-----Measure your transom to see if you need 20 or 25" lower unit.