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View Full Version : Velvet Drive rattles, any ideas


Rick_Seebeck
04-20-2008, 05:08 PM
I have a Velvet Drive 1.52:1 transmission on my 83 stars and stripes. When I bought the boat the transmission had water in the fluid. I drained it twice and refilled with Dextron III. When the boat is first put in gear with the RPMs just off idle there is a rattle in the trans. As the RPMs come up the rattle stops. It is worse in reverse than in forward. The rattle sounds like loose parts and seems to come from the rear of the trans. I have also noticed that the trans does not start spinning until the RPMs come up a bit. It does not start spinning as soon as you put it in forward. You have to advance the throttle a bit in order to get it to start turning the prop. Not the same in reverse. Any transmission gurus out there!

defender1009
04-20-2008, 06:49 PM
Same thing happens on my 1:1 transmission. I've read about it a lot in the archives on this site, and from what I can tell, it's a fairly normal condition, and is usually indicative of idle speed being set too low.

Someone with some serious knowledge will chime in shortly, but if you do a search, this is a really common "issue".

Rick_Seebeck
04-21-2008, 07:14 AM
I searched the forum and found a thread relating to my noise. Is it ok to run motor oil in the older velvet drives? Anybody?

Lakeview
04-21-2008, 09:25 AM
Make sure the noise is really from the trans and not a worn/broken spring on the damper plate that bolts to the flywheel.It will make the noise only at idle

bigmac
04-21-2008, 09:36 AM
Make sure the noise is really from the trans and not a worn/broken spring on the damper plate that bolts to the flywheel.It will make the noise only at idle

I agree, I think that's a more likely source of the rattle.

skihorse
04-21-2008, 10:19 AM
My PS tranny rattles when you are at speed and come off the throttle. Does that sound like a damper issue?

(Sorry for the hijack)

jobondur
04-21-2008, 12:32 PM
I have a 96 Maxum 210SS V-Drive with a velvet drive tranny hooked to a walter v-drive. Below is what the Mercruiser Service Manual (#17) says to use for the transmission fluid for the velvet drive (for my year and model).

Velvet Drive - 10 wt. tractor hydraulic fluid meeting the C-3/TO-2 specification (preferably Mobil 423, Chevron, or Citgo).

The stuff is kind of hard to find, I am in the process of changing mine in the next week or so for the first time and I ended up having to go to Tidewater Fleet and getting them to get me the equivalent (Castrol #3659 Universal Tractor Fluid). It's $12.43 a gallon.

east tx skier
04-21-2008, 12:36 PM
I'm going off a vague recolection of what my mechanic told me. I seem to recall the words "glaze on the clutch packing" being mentioned. Mine used to do it in reverse in the colder months when we would first start it up. After a minute or so of idling, you could get a repeat performance of it. But that was the explanation if it I was given.

6ballsisall
04-21-2008, 01:07 PM
I'd check the damper plate first off. My 86' did this when I bought it. Bought a whole new trans for it thinking that was what it needed. When I tore it apart I realized it was the damper plate. Needless to say the boat got a new trans and damper plate. :rolleyes:

Bruce Carr
04-21-2008, 04:02 PM
Increase the Idle RPM a little and see if the rattle goes away. The clutch plates are forced together by oil pressure from the oil pump in the trans. Low RPM will not let the oil pump produce enough pressure if it is somewhat worn and lack of sufficient oil pressure will let the clutch slip a little causing the planetary gears (reduction gears) in the trans to rattle. If increasing the Idle RPM doesn't fix the problem, check the damper plate. Did you find out why there was water in the trans?

Rick_Seebeck
04-21-2008, 07:04 PM
Raised the idle. Problem went mostly away. Just a little rattle when shifting into reverse. Thanks!!