1986 OMC 4.3 Stern Drive will not go in gear.

[Stuckjoe74]

Hi all, after searching through some threads I haven’t found anyone with my exact issue. I was on the lake last week running full throttle when the boat seemed to shift abruptly into neutral. I have not been able to engage forward or reverse since. I have I have gone through ESA, Ignition Interupter Switch, Shift Cable and Overstroke Switch troubleshooting and haven’t found any problems.

The prop spins freely in in the neutral position but not when shifted into forward or reverse.

Boat is a 1986 Sierra Seaswirl.

Any advice would be greatly appreciated. Thank you

 

[southkogs]

Welcome aboard:

Let's check a couple of things: make sure you don't have a spun hub on the prop. I don't think so, but let's check it.

I'm going to actually guess that the lower drive shaft (near the impeller) may have stripped out on ya'. That's a pretty common happening in the Stringers.

Could also be ball gears letting go. So, maybe take a peak at those.

 

[Lou C]

This is a 1986, is it the last of the stringers or the first of the Cobras?

 

[Scott Danforth]

the stringers had a sticker on them "stern drive", however the year could be either.

if its a stringer, most likely the splines stripped.

 

[Stuckjoe74]

I believe there is a stern drive sticker, can’t say 100% as I dropped it off at a local shop this afternoon. The ball gears seem to be in prett good shape and based on everything I’ve read I don’t think it’s a spun hub. I’m leaning towards the lower shaft also. Will update when I learn more. Thank you all four the assistance.

 

[Stuckjoe74]

According to the shop I took the boat to last week there is a malfunction in the upper drive unit. Looking at somewhere in the neighborhood of $1000 for the repair. I’ve been looking around and the refurbished units run anywhere from $1200 to $2700 minus a core charge. I saw some used uppers on eBay fairly cheap but who knows what your actually getting. I’m fairly confident that I could do the work myself but I’m not sure if it’s worth the effort.

I believe the part number is SW-155C if anyone has any suggestions I would greatly appreciate it.

 

[Scott Danforth]

The upper is fairly bullet proof. Usually the ball gears are let to go too long, or the vertical drive shaft splines strip. Ball gear kit is $150, shaft, sesls, etc in the $300 range

I would question a shop that simply says "malfunction with the upper"

 

[southkogs]

Generally speaking, if a Stringer will idle with the drive attached the upper is mostly working. I'd check that drive shaft and the ball gears before anything else.

I've purchased a used upper for my old electric shift before. Got it after doing a couple months of hunting for about $300 (IIRC). If you're patient and watch Craigslist or have a marine salvage around, you can probably find a working upper relatively inexpensively.

 

[Scott Danforth]

95% probabiliy it is the splines in the vertical drive shaft, item 21 and 28 need to be replaced

buy them here http://www.sterndrive.info/id31.html

watch their videos

Item 21 requires the upper to be pulled apart, new seals, etc installed when putting together.

if you pay someone to do this, it will cost you 5x what it would cost you to do it yourself

if you buy a used one, most likely it will failure, because its not iff the splines fail, its when the splines fail. on a stringer, they all fail. its just something that needs to be attended to.

 

[Stuckjoe74]

Thank you all for the insight. Scott, I fully agree with your statement regarding the shop. I only spoke to the guy on the phone very briefly, planning to go by shop during lunch today to get something more specific. Now that winter is setting in here in Kansas I’m in no rush to get the repair done.

Again, thank you for the assistance.

 

[Scott Danforth]

pull the drive and go thru it this winter. that way the boat is ready come spring.

 

[Stuckjoe74]

You were spot on Scott. Still trying to get #21 out but you definitely called it.