1995 Prostar. Gearbox problem.

[eurosysytem0]

Hi from the UK

A friend of mine acquired 1998 Prostar with a standard gear box/transmission in Oct last year. At that time no issues. He has spent the winter improving its general cosmetic appearance and launched last weekend..

Engine runs perfectly but when putting into gear(forward or reverse) the transmission does not engage.

Checked the lever on the transmission itself and it is moving properly between the three positions. Have disconnected gear cable and confirmed lever is moving to full travel in forward and reverse selection.

The transmission safety when starting solenoid is working properly.

The transmission fluid is at the right level and clear in terms of condition.

In addition there is a two point terminal with relatively heavy duty white wire going off into the loom on top of transmission. What are they for?

Any suggestions on what to check next in terms of diagnosis before all the hassle of taking the transmission out.

All help appreciated.
Regards.

[waterlogged882]

Hi from the UK

In addition there is a two point terminal with relatively heavy duty white wire going off into the loom on top of transmission. What are they for?



All help appreciated.
Regards.

On the Velvet Drive transmission (and likely on your make) that is a circuit for the neutral safety position of the transmission. The wires are non-polar so either wire can go on either post. That is an ignition circuit starting component. To check it and make sure it is indicating "closed" to the circuit (for proper and safe starting) put both wires on one screw post. That essentially bypasses the switch. Try and start.

However I don't think this address your primary talking point. Merely addresses one of your questions.

Furthermore, on the white wires (often yellow and red as well), one white wire connects to the starter relay, the other is wired into the mid-run harness going to the ignition switch "start" post. That is the route of that particular circuit. If it is open anywhere (in this case the neutral safety switch) the engine will not start if it sees an open circuit at the switch, which indicates the transmission is in gear.

If he took the controller off the gunnel to clean or swap cables, make sure he got the cables back on in the proper location. I have seen (dummy me) people put the cables on in their reversed position and the shifter position. Again, I suspect that is not the issue at hand.

I have manuals in PDF if that may help but I need an email address. The stingy folks here allows only a tiny file size for attaching.

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[etduc]

Did you run the boat, on the water last Oct? If the shift-lever, (on the tranny) moves to all three positions. Then one possibility, is fluid pumping pressure. Make sure the fill plug is tight.

Also. trans, steel and abrasive plates can be frozen together. If the tranny, as been recently rebuilt, tranny pressure assembly could be incorrectly installed.

With a boat of that age, rebuilding the tranny is not a bad investment. Even someone with modest skills, can rebuild it.

[RDahler]

Did Your friend take the prop off sounds to me like He may have left the prop key off shaft slipping in prop hub. might look like that is the coupler on the rear of the trans turning when you put it in gear? You might connect a 200psi gauge to the 1/8 pipe plug near the two wire temp sensor should read 135-160 psi. no psi broken flex plate or bad pump.

[eurosysytem0]

More info on the gearbox problem.

First: The boat is a 1998. not 95. Transmission housing has a rectangular look about it.(if this helps)
First RDahler: Its not a prop issue. The Propshaft is not turning.

My friend disconnected the lower transmission oil pipe at the transmission oil cooler. There was fluid in both the pipe and cooler.- reconnected.

Then really slackened off the top pipe connection at cooler and turned over the engine. No fluid leakage. The pipe was disconnected and was found to be bone dry and empty of fluid. Blue down this hose and there was no resistance.

Question: Which is flow and return?

Can I confirm that when you check oil level the transmission oil stick is pushed fully into housing?

[eurosysytem0]

As an aside : Why is it when I click on New Topics my post on this subject does not appear?

[etduc]

to check fluid. Install fluid plunger, and tight. Run engine(doesn't have to be in gear). Turn off engine, then immediately check fluid. Supply/return hose, doesn't matter, which is which.

[waterlogged882]

As an aside : Why is it when I click on New Topics my post on this subject does not appear?

When you are logged in to your account, it is not a new topic per se'. The topic has been viewed by you by virtue of your participation in the thread / post.

When not logged in to the account, you are seen as an unknown user (guest) and the topic is new to said user.

.

[EricB]

From what I read, the engine starts and runs. The trans does not engage in forward or reverse. Snice it's a 98, I'm going to make an educated guess that the trans is a Hurth, not Velvet Drive. If when running, you can putt the dipstick out, and look into the hole. You should see fluid movement. Get a service manual and test for oil pressure. Assuming there is none, I would look at either the drive coupler plate or internals to the trans. Velvet Drives are repair friendly. Hurths are not.

[waterlogged882]

From what I read, the engine starts and runs. The trans does not engage in forward or reverse. Snice it's a 98, I'm going to make an educated guess that the trans is a Hurth, not Velvet Drive. If when running, you can putt the dipstick out, and look into the hole. You should see fluid movement. Get a service manual and test for oil pressure. Assuming there is none, I would look at either the drive coupler plate or internals to the trans. Velvet Drives are repair friendly. Hurths are not.

^ ^ this

Mr. Eurosystem0,
For me, it would help knowing the make and model of the transmission. I suspect (as stated by Eric) it is a Hurth make. I have manuals as we have discussed. I will send in your email if you are still in need.

To another question from you; with reference to Fluid Dynamics principles, one typically suggests that (in this case) for cooling the transmission fluid; where the input hose of transmission fluid into the cooler, goes into the port that flows opposite direction of the of water (intake) flow for cooling. I think either port is OK. Just sharing something I picked up along the way.

Also, from the Hurth repair manual:
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[eurosysytem0]

Guys I have just had a flash back from an old stars and stripes I had with a Ford 351.

Is it possible that I have lost the springs in the flywheel damper plate on the flywheel.

Would that create the problem where the engine runs, but when gears selected, the transmission lever moves at the transmission housing but I get no gear selection?

As you can tell I am clutching at straws.

[chrislandy]

no, it would sound like a bag of bolts being rattled if the springs had gone.

Levels need to be checked when running so if it's "bang on" when off, it may be too low when running.

If you have a pressure gauge, whip out the temp sender on the gearbox and use an adaptor and check when running at idle.

Whereabouts is the boat?

[eurosysytem0]

Hi Chris
The boat is at Hardwick Park Nr. Oxford
This weekend the owner and I intend to suck out old transmission fluid, prime cooler and empty hose an refil with new Dextron II. Then we will retry and see what happens. If it’s not fluid then it sounds lie a transmission Out job which will be a pain. It may be fluid level but it was working ok when it was put away in November. First start this year no gears.

Ian Snow

[waterlogged882]

Hi Chris
The boat is at Hardwick Park Nr. Oxford
This weekend the owner and I intend to suck out old transmission fluid, prime cooler and empty hose an refil with new Dextron II. Then we will retry and see what happens. If it’s not fluid then it sounds lie a transmission Out job which will be a pain. It may be fluid level but it was working ok when it was put away in November. First start this year no gears.

Ian Snow

Pulling a transmission is not that difficult. I typically have to raise the rear of the engine to get a straight shot of removing the transmission. The engine will rotate about the axis of the front mounts (still in tact). Loosen the horizontal locking studs on the front. After that, the transmission will come right off. The standard (Velvet Drive) transmission is right at 95 lbs. and with a gear reduction, it is right at 140 lbs. Your Hurst may vary and the Hurst may come off without having to left the engine. I lift the rear of the engine then use an overhead hoist (or anything similar) and lift it out. While you are there, put a new damper plate on the flywheel. No better time.

US $0.02

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[chrislandy]

If it's still a problem, I'd quite happily take a look. We live near Cheltenham but ski down at OWSC and Reading weekly so could pop in on the way down/up from one of those lakes.

100% change the damper plate if you take the trans out, I used an R&D plate from ASAP Supplies on mine when I had the box out a few years ago.

It takes about 1-2 hours and two people to remove the gearbox if the boat is out of the water depending how stubborn bolts are, mine was a Hurth 450 so just undid the rear mounts, loosened the fronts a bit and jacked the rear up and slid the box off. Even rebuilding the trans is fairly easy so as long as you're fairly mechanically minded.