Loud Bang from Outdrive then full stop-=-Help?

trojandoc · Post by **trojandoc** » Tue Aug 03, 2010 4:49 pm

Hello all,
I'm new to the Trojan club, having purchased a 1977 F26 from a meticulous owner. Single Engine 351, rebuilt 20 hours. Volvo 280T Leg, rebuilt last year.

I've been enjoying sprucing her up as we worked our way through the break in period. Figured out how to tweak the steering issue from this forum. Enjoying the Marina time.

Problem yesterday is we wanted to open her up to full throttle for a bit, now that the engine is broken in. Cruising at 3500rm in a bit of swell, suddenly super high rev sound, followed by a LOUD bang, and stall.

Since we were out of the Harbour and needed to get home, we were able to restart, engine sounded fine, out drive, sounded okay, tried to bring it up to speed and same thing with the super high rev sound, so elected to limp back to the dock.

We wondered if ? leg not locked down, cavitated in swell and then dropped back in (BANG) vs. something more serious?

Just wondering about thoughts on this, I'm used to direct drive inboards, and my trailer is stored a long way away at the moment.

Cheers,
Aaron

captainmaniac · Post by **captainmaniac** » Tue Aug 03, 2010 5:04 pm

In forward it wouldn't be kicking up on you. Most likely some stripped or worn gears in the upper or lower end that are separating when you get enough pressure against them. I had a similar bang / freewheeling with my old Liberator a few years back - there had been a hairline crack in the gears and one day they decided to just let go.

k9th · Post by **k9th** » Tue Aug 03, 2010 5:42 pm

Welcome to the forum Aaron and sorry you are having problems.

From my experience, the symptoms fit a a gear problem in the lower part of the out drive. They sound like they are either worn and barely engaging or the shift linkage is not set right and it is slipping out of gear at higher loads. If they are missing teeth you should be able to tell by the sound even when running slowly since loose teeth bouncing around the housing make a distinct noise and the teeth remaining make a distinct sound when running over the mating gear. If it is a gear tooth failure, it will likely be the pinion gear since that gear sees the heavier load.

I had to replace three sets of lower unit gears in two years. The last two sets were under warranty since the gears were not hardened properly.

turtlem1969 · Post by **turtlem1969** » Tue Aug 03, 2010 7:06 pm

you said the outdrive was rebuilt last year, more then likely what has happened is the mechanic didn't get the shift cable adjusted properly and it is just barely going in gear at the low rpms and when you open er up its not engaged enough to handle the pressure and bang out of gear it goes. has happened to me before with an omc cobra, which is the same as the volvo out drive.

MattSC · Post by **MattSC** » Tue Aug 03, 2010 8:50 pm

Hi Aaron, welcome to the forum. Don't have much time with I/O's, but I was out on a friends boat with an I/O and we spun the hub on the prop. The boat ran OK at slow speed, but the engine would rev up and the prop would just be spinning on the hub. Had to limp back at an idle. That doesn't answer the loud bang though. Maybe you hit some debris? That could explain a spun hub.

Good luck with the boat, would like to see some pics of her when you get a chance. Haven't seen too many F-26's with an I/O. Curious as to how she performs.

take care,
Matt

aaronbocknek · Post by **aaronbocknek** » Wed Aug 04, 2010 4:17 am

yeah, another aaron on the forum!!!

welcome to the group.

aaron in baltimore

randyp · Post by **randyp** » Wed Aug 04, 2010 9:41 am

Welcome, Aaron. I've got a 77 F-26 with direct drive, but had an I/O years ago and it does sound like a gear issue. That being said the advice on the gear shift would be a best-case scenario. Good luck and keep us posted on the outcome.

trojandoc · Post by **trojandoc** » Wed Aug 04, 2010 12:00 pm

Thanks for all the tips, I do think it is a shift linkage/gear issue as suggested. shifting was a bit tricky, but I put it down to a "mature" boat and me not being used to how it handles. Come to think of it my "docking" might improve if the shifting was more responsive.

Currently trying to find a marina I can limp over to without trailering the boat, as I would prefer not to get it out of storage.

Excellent suggestions all, I will now sound somewhat knowledgeable when I describe my outdrive issues to the mechanic.

Cheers,
Aaron
Victoria BC
F26 1977 "Brandywine"

rossjo · Post by **rossjo** » Wed Aug 04, 2010 9:07 pm

"BANG" is the gear s- not a spun prop. Might be mis-adjusted as someone stated. Hope so for your sake, as its an easy fix.

LSP · Post by **LSP** » Wed Aug 04, 2010 9:12 pm

turtlem1969 wrote:you said the outdrive was rebuilt last year, more then likely what has happened is the mechanic didn't get the shift cable adjusted properly and it is just barely going in gear at the low rpms and when you open er up its not engaged enough to handle the pressure and bang out of gear it goes. has happened to me before with an omc cobra, which is the same as the volvo out drive.

Exactly what I had happen to my "lets say" other boat. Would jump (bang) out of gear as soon as you put a load on it.

trojandoc · Post by **trojandoc** » Thu Aug 05, 2010 4:13 pm

Thanks everybody, I'll let you know what happens when I get it out of the water for inspection.

Aaron