Suzuki DT75 Reverse Gear slipping - Help wanted!

[Trevor G]

I've just bought a 4.7 Searider with a 1990 Suzuki DT75 on it.
The engine runs fine but when in reverse the gears slip (I did know this when I bought it) - in forward it's fine.
Before I try and get a new gearbox/lower unit (or maybe replace the engine) I want to take the old gear casing apart in case it's something I can fix.
I've drained the gear casing oil and there are no bits in it and it's not milky - so no water has got in!
However - my first hurdle is I don't understand some of the teminology in the service book I've got!
I'm stuck on part 7 of the attachment - there is no photo if where the cover is at the front of the clutch rod, and I'n not sure what I'm looking for!
Any help much appreciated!
Thanks
Trevor

[martini]

Don't know Soozys at all but I'm guessing they're referring to the top end of the gear linkage somewhere on the side of the engine. On pretty much any outboard this has to be disconnected before dropping the gearcase which is pretty much the next step on that page in your manual, or that's what it's leading up to at least.

[Nasher]

Trevor

Suzuki tend to call the shift rod the clutch rod, and it has a joint in it somewhere between where the lower unit bolts onto the leg and the undertray of the engine, dependant on what model you are looking at. As the instructions suggest, some are covered by a plastic housing.
On my 200V6 it’s just a couple of inches above the lower split.

If I was at home I’d scan a manual, but that will be later tonight.

I suggest you take a look at the microfiche type images on Browns point Suzukis web site, as they are better than a workshop manual.
Suzuki Outboard Parts Catalog Microfiche - Browns Point Marine Service

Edit
Should have said, I’ve made several copies of Suzuki special tools to get into the lower unit on my 200, I’m not sure they will fit your engine, but you’d be welcome to try.
Once inside it’s all pretty basic stuff as long as you don’t replace anything that will affect the shimmed length of the assembly.
Replacing items like the dog clutch, which might be your problem, doesn’t effect it for example.
I assume you’ve tried adjusting the shift rod etc already.

Nasher.


Nasher.

[Downhilldai]

There's no cover in front of the clutch rod on a DT75. You need to disconnect the top of the clutch rod from the linkage below the carbs.

Sounds like your clutch dog and/or reverse gear are worn and need replacing. It's a lengthy re-shimming job if the reverse gear needs changing, but the clutch dog alone is straightforward enough.

Clean gear oil could be down to a recent oil change. As you've recently bought the boat, I don't suppose you have detailed history of when the lower unit was last checked and the gear oil replaced?

Did I mention that I've got a DT75 for breaking?.......

[Nasher]

Trevor

Have a read through this with a cup of tea

http://www.rib.net/forum/f36/dt200ef...oes-32642.html

It will either frighten you off, or show you at least some of what is going on inside.

Nasher

[Burtox]

Originally Posted by Nasher

Trevor

Have a read through this with a cup of tea

http://www.rib.net/forum/f36/dt200ef...oes-32642.html

It will either frighten you off, or show you at least some of what is going on inside.

Nasher

OMG!!!! I have just read through the link.... my hair turned grey then fell out

[Trevor G]

Originally Posted by Downhilldai

There's no cover in front of the clutch rod on a DT75. You need to disconnect the top of the clutch rod from the linkage below the carbs.

Here's a couple of photos of what I think I need to take apart.
I think that it's the split pin and nut in the 2nd photo that are the cotter pin and connector pin, although the descriptions don't really sound right....

[Burtox]

I bought a 90 hp Honda with a reverse gear that was knackered. It was the clutch dog as you can see from the photos the previous owner used to slam the boat into reverse whilst going fowards (RYA instructor) .
The first pic shows the reverse side which would jump out of gear and make a nasty crunching sound which is a similiar to the sound that your missus makes whilst driving your car. The other pic is of the forward side which went in to gear fine. Just thought I would show what is good bad and ugly.

Hope this helps, Good Luck.

[Nasher]

Trevor

I think you're looking in the wrong place.
You are looking at parts 2 and 3.

The vertical shaft needs to be split from the horizontal one at the other end.

Nasher.

[Chris]

Originally Posted by Trevor G

I've just bought a 4.7 Searider with a 1990 Suzuki DT75 on it.
The engine runs fine but when in reverse the gears slip (I did know this when I bought it) - in forward it's fine.

Trevor, when you say it slips, does it click like its not in gear properly?

Chris

[whisper]

Hi Trev,

When I purchased the 4.7 about late Jan this year the owner said he had it serviced in late 2010 which included a gear oil change.

It was going in forward and reverse ok until we launched at Baiter on Bank Holiday Monday when a ski boat almost reversed into the side of us near the slip with his engine tilted right up and his prop nearly out of the water. To save a nasty collision and probably the tubes I went from slowly moving forwards to reverse quite quickly and his prop missed us by about 6 inches

I then moved forward again for about 20 feet to sort a few things out before we headed out of the harbour, by this time the current had turned us round so I put it in reverse to turn and that’s when it jumped in and out for gear for the 1st time. I tried it a few times but realised it was time to head home.

If it helps others and like I showed Trev when he bought it, if you put it in reverse and turn the prop it starts to turn the engine over but then slips after about a 10 deg turn, when it does this the gear connection also moves forward up in the engine where the control cable connects to the gear lever and after it has slipped onto the next tooth it engages again.

I’m not sure if it is supposed to lock into position when in gear but it was definitely not doing that after this fault started.

Hope this all helps

[Chris]

I would disconnect the cable first and try manually putting it in gear. It may be a cable adjustment issue if you are lucky.

[Trevor G]

Originally Posted by Nasher

Trevor

I think you're looking in the wrong place.
You are looking at parts 2 and 3.

The vertical shaft needs to be split from the horizontal one at the other end.

Nasher.

That's what I thought - but I can't see where I can get to separate the two - I'm sure once I know where to look for either the joint where pins 13 and 14 are, or maybe pin 12 then it will be blatantly obvious!

[Chris]

Trevor,

as per my previous post have you tried disconnecting the cable and shifting it manually...

befor you start tearing it down it might be worth making sure..

[Trevor G]

Originally Posted by Chris

I would disconnect the cable first and try manually putting it in gear. It may be a cable adjustment issue if you are lucky.

I'll give this a go 1st thing in the morning.

[Chris]

Originally Posted by Trevor G

I'll give this a go 1st thing in the morning.

The only reason I say this Trevor is I had a very similar problem on my first outboard. It went into reverse fine until I had to slam it into reverse on an occassion when I ran over some flotsam and old rope, then it kept jumping out of gear just in reverse.

I found that the cable adjuster had jumped out of place and had allowed the cable to move slightly,just enough to prevent it shifting fully into reverse. When I disconnected the cable it went into reverse fine and I breathed a HUGE sigh of relief..

Good luck

[Nasher]

Originally Posted by Trevor G

That's what I thought - but I can't see where I can get to separate the two - I'm sure once I know where to look for either the joint where pins 13 and 14 are, or maybe pin 12 then it will be blatantly obvious!

Parts 13 and 14 are below the plastic clip holding the round magnet which catches the swarf inside the gearbox, so they are down inside the gearbox and you can't get to them to split it there. It isn't really clear what part 12 is.

On my 200 there is an external joint just above the lower casing which doesn't appear to be present on your 75. You should find that the flattened end of the vertical rod passes through the rubber seals etc shown on the image I posted, so the whole shift rod is removed with the lower casting/gearbox.

The manual I have which covers DT40s of about the same age shows a threaded connector in the middle of the vertical shift rod which allows it to be split like my 200, so it seems odd your 75 does not have anything like that.

Nasher.

[Downhilldai]

Originally Posted by Trevor G

That's what I thought - but I can't see where I can get to separate the two - I'm sure once I know where to look for either the joint where pins 13 and 14 are, or maybe pin 12 then it will be blatantly obvious!

Right then, here we go:

Using Nasher's diagram, undo nut 3 which will allow the shaft 1 to slide through the bracket 18, thereby disconnecting the crank pin at the opposite end of the shaft 1 from the gearshift rod 8.
If you've removed all the nuts/bolts holding the lower unit to the mid section, the lower unit will now be free to drop out and land on your foot. The gearshift rod comes out complete.

[Trevor G]

Originally Posted by Downhilldai

Right then, here we go:

.
If you've removed all the nuts/bolts holding the lower unit to the mid section, the lower unit will now be free to drop out and land on your foot.

Note to self... if plan "A" (which is Chris's very sensible idea of checking the simple things first) doesn't work - make sure I put my steel toe-capped boots on before attempting to drop the lower unit!

Thanks guys!

[Downhilldai]

Originally Posted by Trevor G

I'll give this a go 1st thing in the morning.

To do this, before you start adjusting anything, with the motor switched off, engage reverse gear with the remotes (you may need to turn the prop a little for the clutch dog to engage). then disconnect the gearchange cable from the linkage, checking while doing so, whether there is any further movement in the linkage.

The cable should be adjusted so that when the remote is in the neutral position, the gearchange linkage should be in the centre of the neutral position. This is quite straightforward to achieve. When the gearchange lever is in neutral, with the engine not running, try turning the prop by hand to check whether the clutch dog is slightly fouling either the forward or reverse gear (faint clicking noise). If it is, then the cable needs adjusting.

Good luck.