88' OMC Sterndrive 350 V8 Banging/Skipping

[diobe]

Hello,

It seems this issue is more then well known but I'll take any advise I can get:


I just bought a 88' Forrester 227 Escape this year and it's in pretty good condition. I'm new to boating but to me, as a new boater, it seems to handle like a dream. Other seasoned boaters that have been onboard with me agree in spades.


Its a cuddy cabin with either a 5.0 or 5.7 (5.7 I think) OMC. The engine has been replaced at some point but with the same type it came with.


My big issue is the OMC sterndrive. It "Bangs" or "Skipps" in forward gear. I read a ton about the issue and have found that a company GLM makes stronger replacement gears (note: the need to be replaced as complete set as they are geared a little differently). I also found that a faullty or stiff Trasnsom Shift Cable has been identified by many people to be the root cause of the issue. (i've read the hastings web post) In addition I've seen info to indicate that many people change out the gears just to have then repeat the same process of Banging seldom then occasionally to frequent and often to failure. A mechanic at the shop told me that if the gears keep skipping after replacement they most likely haven't been "shimmed correctly"

Currently I have mine in for service and they are replacing the cable and a worn out Shift Bushing that fell out when they took off the sterdrive to put in the new cable. They tell me this "could" be the cause of my trouble and to try it out before getting into more costly repairs. I plan on tesing this week or next. If its not the problem I guess I'll be looking at putting in new GLM gears (about $550 + labor) or a full new lower unit with the Heavy GLM Gears already Installed about $1600 + labor)

The full lower unit seems to be my best choice as I was told from the former owner that the gears and dog clutch were put in new the previous year so if there is an alignment or other "tricky" issue I think it better to pay for the new assembly as opposed to pay for the Labor to hopefully correct the issue.

What do you you guys think? have at it!

 

[Liquid_force]

Re: 88' OMC Sterndrive 350 V8 Banging/Skipping

I had similar symptoms in my '89 omc.
In denial that I was looking at a lower unit problem I wrote it off as an engine miss, until one day the clunk started happening every few minutes instead of every couple hours, and before long we were stranded.

I found a set of replacement gears on ebay for about $200 which was way less than anywhere else.
The shop that did the work said the old gears really weren't that chewed up, so it may in fact have just been a poorly adjusted shift system (I don't believe they replaced the cable).
Anyway - since the repair 3 yrs ago we have had no drive issues at all.

From the hastings.org OMC write up it seemed to me that the gears themselves were never the real problem, but that a poorly designed shift cable led to a lot of gear failure.

I personally don't see a drawback by saving the few hundred $$ and going with a new gear set vs a whole new lower unit if that's what it comes down to. Hopefully the work they're already doing will take care of it.

 

[fastinated]

Re: 88' OMC Sterndrive 350 V8 Banging/Skipping

Same problem.. Currently rebuilding.. Got my last bearings and $161 shim tool last night! Yep mine was doing the same thing. I took the outdrive apart about 4 years ago to do a reseal and inspect.. Well I replaced the cable while I was at it. Had no problems for a while, but at first it would skip under power (planing) just after coming out of neutral.. Ok thought it was normal. Then recently it would do it while cruising once and a while. Think it was deteriorating.. But it got worse the last time I went out. I took off the prop and bearing carrier to get a peek, well the pinion and fwd gear was toast. They had all their teeth, but they were some redneck teeth!!! So I attribute the problem to my cable set up. So $750 + my labor and hopefully all will be well again. But you know when I got all the parts out and compare them to my old ones. The clutch and the part of the gears the clutch grabs looked just like new.. Think it was the shock of the slip under power that deep sixed the gears. Now the gears are still really good for engagement so I know the gears weren't slipping it was the clutch. God I hope I don't do that again!! Leaving for the keys in 1 week for 2 weeks.. Last time I went I put an engine in a week before. This time I'm rebuilding the drive!!

 

[diobe]

Re: 88' OMC Sterndrive 350 V8 Banging/Skipping

UPDATE

Go the boat back and took it for a run.

With the new cable and shift bearing it deffinately shifts "chrisper" into forward.

I did some running around and witghout a problem and began hoping it was solved. After shutting down for an hour (adrift enjoying the sun) I restarted and began heading for home. Then I thought i heard the "bang". Hoping againt hope I stopped and restarted. Yep it happened again. Thrird time around no noise no band.

So the issue - while deffinatgely improved, is not gone completly


I'll provide more updates as I continue to use the boat and adivse on the drives operation

 

[diobe]

Re: 88' OMC Sterndrive 350 V8 Banging/Skipping

I took out the boat a couple of times and Occasionally I would get the bang. I would restart and usually would not happen again.

Third time I took it out when comming home and Got a Bang at about 3000 RPM. Now its as bad as it was before getting the cable and bushing replaced & set-up.

I'd say there may be a cable or cable bussing issue and a resetup may REDUCE the issuue again or the gears are just getting to the point of no return.

Wow this is frustrateing. I think this may not get fixed in 08 as our Boating time in Newfoundland is comming to an end shortly.

Next plan of attack - learn how to service the OMC myself, buy new GLM lower unit $1700 + tax and get a 6 to 9.9 hp kicker motor installed for safety. All toll I'd say an additional $5000 once all set-up. Ouch


The killer with this type of issue is that even with a new lower unit I can't be sure the problem will be solved. At least I will be able to get back in with the kicker. :redface:

 

[diobe]

Re: 88' OMC Sterndrive 350 V8 Banging/Skipping

I purchased the new GLM lower unit. It arrived and looked in good shape - no shipping damage.

Assembled the upper and lower and Pressure tested the drive (10lb) - It Failed and failed a vacuum test as well. Leaking around the the Shift Arm Wiper and the larger seal for the housing that surrounds the Shift Rod on the new lower unit.

Dissassembled and sent back to Vendor. Arrived back this week. Will assemble and test tonight.

 

[diobe]

Re: 88' OMC Sterndrive 350 V8 Banging/Skipping

Update

Last fall after much back and forth with the lower unit vendor and my local Boat Service Center (about the leaking lower unit) the end result was that the vendor took back the lower unit and refunded my money.


I have since had the gimble bearing, both bellows and stern drive serviced - includeing the rebuilding the lower unit (Gears, Clutch, Drive Shaft-etc...) - all professionally done. (1 year waranty on parts & labor)

I hope to get my first test on the water in May/Early June.

I have a question regarding an rpm stumbling I experienced (around 1900 to 2200 if I remember correctly) but will post this separately. I am trying to get this running 100% correct off the start so I don't run into the same issue - at least for a few years