1994 OceanPro 150 lost reverse, sort of

[archcycle]

I've owned this motor a long time with no gearcase trouble at all. Last time out going home waiting my turn at the dock out of seemingly nowhere it had a very hard time hitting reverse. Two clacky engagements later I was on the trailer. Got home and found the prop now spun freely with a slight un-engaged dog clacking when reversed from the controls. Gave the cables some adjustment and no improvement even all the way biased to reverse. After pulling the cables off I can manually push the shift lever into reverse and it engages solidly at the prop so it doesn't seem like it would be a dog issue? The control cables are in good shape and move freely and overall throw checked out against the OMC manual, but they could never get as far back as I'm manually moving the shifter to get to R, it is pretty far.

This seems weird to me because it has always shifted smoothly snapping directly into F/R with an immediate gratifying thud, so worn down gearing would be surprising. I've never had any reason to tamper with the shift rod height and it's been 2 years since the last impeller change so I know that isn't to blame.

I've rebuilt an omc lower before years ago but am hesitant to pull this apart when it is actually able to solidly engage R. Any thoughts on what else I can check before going that route?

 

[Chris1956]

Take a look at where the shift lever goes thru the gearcase surface. Many of those have a shift cover that will swell and grab the shift rod. It makes getting into reverse very hard. The cure is a new shift cover.

 

[archcycle]

Thanks @Chris1956 I will take a look at that when I get the gearcase off this weekend.

Would that be #71 here? I don’t mind picking up a couple of $10 “maybe”s this afternoon while I will be close to marinas with parts. Weekend beach traffic near me makes throwing parts at something a little more appealing than than otherwise would be

 

[Chris1956]

The cover is part #45. The shift rod goes thru it, and the aluminum can swell.

 

[archcycle]

That is the first clear explanation including exactly ‘what’ that I’ve seen even after googling thank you. Only thing I ended up being able to get today was a seal kit, which was mostly to encourage myself to just get started and pull it all apart if the cover does not end up being clearly the issue.
Will follow up once its off.

 

[flyingscott]

Before you take everything apart how about some simple diagnostics. Does it shift into reverse with the cable disconnected? Does the shift box have any broken parts? Any problems with the linkages themselves? A swelled seal would affect forward AND reverse.

 

[Chris1956]

Actually, the swelled cover only affected reverse on my motor. Forward worked fine. Not sure why that was, but it was.... The forward part of the rod may have been more worn down?

Arch, make sure to measure the length of the shift rod, in neutral, offset facing forward. Measure from tip of shift rod to top of gearcase, not top of shift rod cover. On my '98 Johnny 150HPV6 60* 25" model the shift rod height is 26 1/4". A 20 " gearcase would have a 21 1/4" shift rod height. I am not sure if your shift rod is the same......

 

[archcycle]

Well its fixed. I did some facepalm bad initial troubleshooting, measuring the throw on the cable’s end but not the throw of the shift lever while attached. The shift cable’s business end was moving the full throw in PULL (fwd) but turns out not in PUSH (rev) while it was pushing the shift lever, so as I complained in the original post that manually shifting to R did engage (and as @flyingscott pointed out), and by control cable did not, there was a red flag that I paid no attention to…

Back to facepalm troubleshooting - i had not pulled the whole cable out to inspect it. The cable was fubar. $38 and quite a few wasted hours of googling and sweating.

With hindsight cable is a very clear reason to just suddenly lose the PUSH gear, should have pulled the whole thing when testing, that took 5 minutes

thanks both of you