VP 5.7GS PEFS SX Slow speed for RPMs

dlatshaw

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First post after lurking here for years. Used to have classic fiberglass boats with Mercury 1000 outboards. Thought I'd "upgrade" to a newer boat and have less problems... :) So i'm more accustomed to working on outboards that I/O so please bear with me.

Last weekend I had to work on the control box because the handle was coming lose. This is a 2000 Chris Craft 232 with the above mentioned VP gear (chevy block, btw). But they decided to use an OMC control box instead of a VP. I worked through that problem with some posts on this forum. When I went to start the boat before taking it to the lake yesterday it wouldn't start, I had the handle installed a few notches off and the neutral safety switch wasn't engaged. Fixed that and went to the lake.

We ran up and down the lake about 20 miles with no problems all day. On the way back to the dock we did some donuts, nothing too wild, probably 30ft diameter. After the last one I stopped to talk to the family (engine still running) and when we went under way it was fine until I hit about 5mph. The engine will rev to 4000 RPM but the boat would shake and only go to about 10 MPH, I can usually top out at around 40 MPH at 4000 RPM.

We idled back to the ramp and I thought I'd find a busted prop or something wrapped around the prop but it looked fine.

I have not gone out to work on the boat yet but am wondering if anyone has any ideas. Is it possible for the outdrive to not quite completely shift into gear, since I was messing with the controls? Where should I start?

Thanks!

Dan
 

alldodge

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May not be fully engaging, but then there would probably would have more grinding

Either that or engine coupler, drive or pro hub
 

dlatshaw

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Thanks for the quick response! I wasn't sure if the boat would move at all without fully engaging. There was noise that I wasn't used to. I'll look at adjusting the linkage and check the prop hub. The other items might be above my current pay grade.
 

alldodge

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Check the oil level in the drive, it has a plug in the top which is a dipstick

SX dipstick.jpg
 

dlatshaw

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I drained and refilled the oil at the beginning of the season but I'll check it. I haven't checked it once a month like the manual says.

I did check the prop hub by removing the prop and it appears to be fine.

When I had the shifter in reverse the prop moved freely in one direction and stopped turning sharply if turned in the other direction. When in forward the opposite direction moved freely, as expected. But, when turning the prop by hand instead of a solid stop there was slight tension for a very short time then it stopped. Hard to describe and don't know if it's relevant.
 

alldodge

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If you smelled burnt rubber when this happened then it would be the coupler
 

dlatshaw

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I don't remember smelling burnt rubber at the time, but when I removed the prop hub I thought it smelled burnt. Could have picked up the smell? I'm going out to check the oil now but don't have a lot of time to work on it today.

I've removed the lower unit from an outboard before, but never from an I/O. Maybe I'll be getting some experience removing the entire out drive.
 

alldodge

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Removing the drive is not hard, its just a bit heavy

You wouldn't smell burnt rubber from the prop hub being under water, but would smell it if it was the engine coupler
 

dlatshaw

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The oil level was good.

I disconnected the linkage and shifted by hand. Here are pictures of the shifter travel with and without the linkage attached. I think they look the same.

Is there any way of checking the coupler without removing the entire I/O?

Thanks again for your help!
 

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dlatshaw

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I'll have to read over some the "adults only" posts again. Removing things isn't usually my problem it is getting them back on that worries me. I don't have all the specialty tools for alignment and what not.
 

alldodge

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Run it on a hose and see if it shifts in/out ok.

If its ok on a hose, mark the prop and prop shaft location. Put back in the water and see if it runs. Pull it back out and check prop location to see if it moved. If it moved its the hub, if it didn't is the coupler
 

dlatshaw

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My money is on the coupler. The hub is one of those rigid plastic ones that shatters when it breaks. It's not shattered but I suppose the brass ring in it could spin. I have other props and hubs so I can take those along to try too.
 

muc

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I

When I had the shifter in reverse the prop moved freely in one direction and stopped turning sharply if turned in the other direction. When in forward the opposite direction moved freely, as expected. But, when turning the prop by hand instead of a solid stop there was slight tension for a very short time then it stopped. Hard to describe and don't know if it's relevant.

This sure sounds like a glazed cone clutch to me.

If you didn’t use genuine Volvo Penta gear lube last time. You might be able to save it.

Drain in all the lube, let it drain for 8 or more hours. Refill with Volvo lube. Launch the boat and drive around in reverse for 10-15 minutes. Change the lube one more time, letting it drain overnight.

I’ve gotten a few more years out of lightly glazed cone clutches that customers had used cheap lube in. Works about 30% of the time.
 

dlatshaw

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I used mobile one full synthetic. I've had the boat three years and that's what I've used each year when I drained an refilled it. It's worth a shot, fairly easy to do. I thought though that mobile one was one of the options you can use? Not questioning your knowledge, just asking if anything other than Volvo Penta lube is ok.
 

alldodge

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The boat will move at idle just not much higher, for me that's not the clutch, but no VP expert
Sounds more like prop or coupler
 

muc

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The boat will move at idle just not much higher, for me that's not the clutch, but no VP expert
Sounds more like prop or coupler

I assumed that he has full power in reverse. This would rule out the coupler. And he says that he has a plastic prop nub, they don’t slip —- they fail completely.
 

muc

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I used mobile one full synthetic. I've had the boat three years and that's what I've used each year when I drained an refilled it. It's worth a shot, fairly easy to do. I thought though that mobile one was one of the options you can use? Not questioning your knowledge, just asking if anything other than Volvo Penta lube is ok.

Question my knowledge? Of course you should, this is the internet. I see people offer advice with the best of intentions, but it’s clear that they really don’t know. I’m human so I will make mistakes.

Years ago Mobil 1 was a approved gear lube for Volvo’s. But I’m told they changed something in it. It is no longer a recommended lube.

Here are some of my reasons for making the recommendation I did for you.

Your “above my pay grade” I totally understand, I’ve repaired many customer boats that would have been a cheap bill, but they had tried to fix it first and made it so much worse. I feel bad when that happens. Gear lube change is pretty easy. Buy new o rings and lube, drain lube and remove dipstick and level plug, refill slowly from the bottom until lube comes out the level plug, replace dipstick and level plug, remove fill hose and replace drain plug, run engine for 5 minutes, let set for 10 minutes and check the level on the dipstick.

You have one of the two classic symptoms of a glazed cone clutch. And I’m guessing that you have already experienced the other one. Has it been making a little more of a clunk going into forward then reverse, maybe taking a little longer to engage forward then it did when new? Or maybe the engine RPMs had to increase a little bit before forward engaged? These symptoms usually (but not always) preceded the no full engagement.

A slipping clutch is a symptom of something else that is wrong, so it’s important to try and determine what that is.
There are many causes. The main ones are, high idle, sloppy shifting habits, misadjusted shift linkage and the wrong lube. There are many more, but those are the ones I see the most.

The lube one, I’ve never quite understood. I’ve lost count of how many Volvo drives I’ve rebuilt, but it’s in the hundreds. I’ve been in drives that are 5-15 years old and according to the customer have always run non Volvo lube. I’m in there because they hit a log or rock and there is NO glazing on the clutch or gear cup. None.
Then I’ll have one come in for slipping. Customer had us do the gear lube for the first 8 years and now for the last 1-4 years they have been doing it themselves. They have been using Mobil, Amsoil, MerCruiser or something cheaper. And I can’t find anything else wrong. But I have also had slipping in a few drives that have only had Volvo lube, and the only thing wrong (that I can find) is the clutch and cup are glazed. Maybe I’m missing something?
And then there are the drives that I don’t tear down, all I do is change the lube twice. Fixed it! But those are usually boats that the customer is selling or has had a lifestyle change and they rarely use it anymore. So I really don’t know how long it will last.

Like i said earlier, I really don’t know why. I just know it is very rare to have a Volvo that has always used Volvo lube start to slip without something else being wrong. But I’ve had many that only the reason I can come up with is the lube.
 
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muc

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I should add to this “oil” thread. Full disclosure for the people who know me and follow these posts.

I run MerCruiser lube in almost everything I own. Differentials and transfer case in my truck and cars. It’s in the lower unit of my Evinrude, it’s in the gear boxes of the snowblower and tiller. Would I use Volvo lube in them? In a heartbeat if I could get it as cheap as the Merc stuff.

But i only run Volvo in Volvo’s. I’ve just seen too many problems.
 

dypcdiver

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Thanks for sharing that with us muc, I bought 7 years ago 25Ltr of Mobil 1 SHC which I use in my Toyota Land Cruiser and the DP-SM. I just hope it is the earlier type that was recommended!! Fingers crossed.
 

sin1000

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Looking at the pics you attached does it look like the small pin below the linkage look like it has moved looks shinny while the rest is dull looking looks like it is bound up where linkages meet, maybe just me saw shinny pieces

NVM put glasses on and blew up pic can see gap in linkages now
 
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