Velvet Drive won't shift when hot

I'm having a problem with my Marine Trader 36' starboard transmission. The transmission shifts fine when cool. This past weekend we were pulling into a crowded anchorage after a 5 hour cruise. Tried to shift to neutral but the shift handle would not move (panic!). The admiral tried to shift from the lower station, and after a struggle, she finally got it in neutral. Once anchored we tried to shift, but the lever would not move.

Next morning all was OK. Shifted fine. Fluid full. Removed cable. Shifted easily by hand. Checked cable adjustment - seems on the money.

Returned home the next day and had the same problem.

Could this be something simple I'm missing? or am in for a rebuild? Any suggestions on who to use if I need to have it rebuilt? We're located in New Jersey.
Thanks!

What condition is the ATF in the transmission in? Normal pink, brownish? Does it smell normal or burnt? Is the ATF at the correct level? Is the transmission running abnormally hot?

Next run check temp of gearbox with IR gun. Could be related to getting hot. Normal temp for these is around 150F or less. If temp is fine, spool valve could be getting sticky, not hard to take apart and clean.

Marin, the ATF looks and smells new. I need to recheck the level, as I've been checking it cold. Just read it should be checked hot.

Ski, we'll take her for a spin today and check the temp.

Thanks for the advice. I'll report with my results later.

Can you shift the transmission OK with cable removed and transmission hot? Also clean and lube the slide/lever arrangement between cable and transmission lever if so equipped. Mine binds at that point unless regularly cleaned with WD40.

Pretty unusual for selector spool valve on tranny to bind up, even if it got hot. Could also be one of the helm quadrants having some loose hardware that bound up. A pin backing out and catching on something, for example.

I'd inspect underneath each quadrant.

Take cable end off gear lever on trans and see if it shifts smoothly by hand.

Losing control of the tranny is a big deal.

OK, here's an update. Ran at cruising speed for 2 hours. Temp of trans was 160f to 165f. (port trans 135f) Transmission shifted normally. Removed cable, shifted smoothly. Checked fluid while hot - needed a few ounces to top it off.

In checking the fluid I found it wasn't as clean as I had thought, in fact is was brown.

Today I changed the fluid twice, running in gear between each change. I'm hoping my occasional inability to shift and high temperature was bad fluid.

Could my shifting problem just be old fluid? The boat is new to me so I do not know the last time the fluid was changed. Or could I have something else causing the fluid to turn brown?

Thanks everyone for your advice.

Check fluid for water, brown color sounds suspicious. Maybe a leak in transmission HX.

Sounds like the tran-cooler is leaking water into the fluid. Changing it then a test drive and check again for color. Had water in fluid and had to get trans rebuild. Installed temp sensors on both trans with alarms at the bridge. Water and fluids don't mix.

Was the fluid brown and smelt burnt? Or was it brown like chocolate milk?

Brown and burnt is clutches slipping. Brown like chocolate milk is water in the fluid.

The fluid was brown like black coffee. It did not have a milky look at all.

I heard from the previous owner last night. He had the trans rebuilt in 2013. He said he was having problems after the rebuild and he had the cable relocated to provide a straighter line to the shift lever? Then all was OK.

If the clutch is slipping, does that mean it's ready for another rebuild. Is there any test to show that it is really slipping? What might happen if I continue to run it with the new fluid.

Thanks again!

Suggest you get your transmission fluid anlayzed ASAP and post results here or on Boatdiesel.com

If it's brown like coffee, smells burnt and you're having issues shifting, there is no need for a fluid analysis. Just run the symptoms by a good tranny guy.

mike_nickens1 said:

The fluid was brown like black coffee. It did not have a milky look at all.

I heard from the previous owner last night. He had the trans rebuilt in 2013. He said he was having problems after the rebuild and he had the cable relocated to provide a straighter line to the shift lever? Then all was OK.

If the clutch is slipping, does that mean it's ready for another rebuild. Is there any test to show that it is really slipping? What might happen if I continue to run it with the new fluid.

Thanks again!

Click to expand...

You may have more than one issue but one may be causing the other. Normally, those transmissions run between 135-150 and both should run very close to the same temp at all times. The fact that the one giving you trouble is running a fair bit hotter than the other is something that needs to be tracked down. Really only clutches slipping or a blocked cooler can make it run hotter.

Judging by what the PO said, he had the same shifting problem you are experiencing. Frankly, I find it hard to believe anything going on in the transmission can cause the lever to lock up. Shifting only involves rotating a cylinder about 30 degrees. However, you may have a cable or control that is hanging up under certain circumstances. If there is *anything* going on with the shifting its possible it is not shifting fully INTO gear which definitely can cause clutch slipping and will make the trans run hotter AND will darken/burn the oil. This should be understood/corrected before you use the boat any further because if the clutches are slipping you will quickly trash them.

There are plenty of Velvet Drive manuals on line for free that clearly describe how to check and set the shifting. If the shift lever adjustment proves to be good, a next step would be to carefully check the controls and cables for loose screws or other components that may be "catching" on an edge or otherwise binding when trying to shift.

Ken

Ken, Thanks for sharing your advice. I'm gong to completely examine the cabling.
I'm wondering if something hung up on the cable system it could have pulled the transmission slightly out of gear causing the clutch to slip and burning the fluid?
Thanks again!

Looks like you already answered my question in your last post.
Thanks!

mike_nickens1 said:

Ken, Thanks for sharing your advice. I'm gong to completely examine the cabling.
I'm wondering if something hung up on the cable system it could have pulled the transmission slightly out of gear causing the clutch to slip and burning the fluid?
Thanks again!

Click to expand...

Yes that's possible. A VD uses pressurized oil to shift and HOLD the clutches shifted. If the shift lever (on the transmission) isn't all the way in the correct position, not all the pressure will get to the clutch pack and it can allow the clutches to slip.

If you get the manual, it talks about the correct shift lever positions. Its easy to check and is done with the engine not running.

Ken

OK, here's the GOOD, the BAD and the UGLY news on my transmission.

The Good: I've gone through the cabling and the transmission shifts perfectly. Two trips totaling 6 hours.

The BAD: Temperature now up to 200 degrees! Temp of fluid going into trans cooler 165 degrees. Temp of fluid coming out of cooler 115 degrees.

The UGLY: The fluid has already started turning brown. Also, the transmission has developed leaks. I'm thinking it's just a matter of time before it self destructs.

I think I'm going to need a rebuilt transmission. I'm pretty sure it can be removed while in the water. I've removed smaller transmissions on sailboats, but the size of this one may put it beyond my skill and strength level.

I'm currently on the New Jersey Shore. Any recommendations on companies that could handle this job in my area?

Thanks!

Definitely sounds like its slipping - when they start they go bad fast because the clutches wear very quickly when slipping under load. Other access aside, if you have the room to move the shaft back at least several inches, it should be possible to R & R the transmission while in the water. I didn't see where you mentioned what model it was, but assuming you have one with a reduction (this would be common), it will weigh somewhere around 160-170. 2 guys can lift it, but its work.

I'm going to do my port VD this winter (Has almost 5K hrs on it). I will be using a small hand winch and a double A frame to get it up to the salon level. From there two guys can get it to where I can use my boom winch to get it to the ground.

Ken