Transmission screaming when let off the throttle on 92 Excel

[92Excel]

Occasionally, when letting off the throttle from 29-35 MPH I get this screaming that sounds like its coming from the transmission. I have a 92 Excel, v-drive with a Velvet Drive tranny with 680 hours. Any ideas?

[tryan]

my v-drive has a seperate box, but i would call mark at marinegears or vince at skidim. mine makes some odd sounds when the prop is pushing the tranny instead of the motor. is it a bearing squeal? anything in the old oil?

if you want a little entertainment log onto v-driveboat. those guys are horsepower crazy. they mainly run casale v-drive trannies, but could probably answer a velvet/bw question.

[92Excel]

mine has a seperate box too but I don't really know where the noise is coming from. I'm just getting to know the boat and have only had it out 3 times before winterizing. Thanks for the contacts, I'll try them.

[tryan]

take out the intermediate shaft between the tranny and the v-drive, and swivel the cardian ( double u-) joint around. see if you can feel any slop. you can swap out the u-joint with a c-clamp or a prop puller.

if nothing is obvious, you might take the prop shaft off also and see if the bearings at the flanges are loose on the v-drive. from the posts on v-driveboat, replacement is a walk in the park. a thrust bearing in the tranny would be a little tougher.

i'm going to put a saftey collar on the intermediate shaft when i get into restoring the '69. kinda scary having a chunk of metal spinning 5 grand right under your feet.

i'll post your question on marinegears and see if mark will answer.

[tryan]

yo, mark replied off the marine gears message board.


.................................................. .....I've never heard of that problem in any transmission. The problem with transmissions is they act as an amplifier for any noise problems in the drive train or the engine. The problem could be anything from the stuffing box to the crankshaft. Sorry I couldn't be of any more help.........................................


sorry, but you'll have to dig deeper into the well...........

[mkcarte2]

I have an 86' 2001, and sometimes I get this noise when letting of the throttle. It doesnt do it every time, and it doesnt last but a second or 2 so I dont have enough time to find it. Its not really a screeching though, its more of a moaning sound, its really weird I cant describe it

[tryan]

when you say 'scream' i would still suspect the clutch pack is worn or burnt or low pressure and/or air in the system. clean the pickup screen at the cooler hose and change the oil a few times to see if it goes away. it seems it would slip or scream under acceleration before it would do it on the overrun.

there is a test port on the top of most trannies and it's like 60psi at idle in neutral and 110-120 psi engaged. i don't know about the seperate v-drive box having a pump. i think it's just two bevel gears and a few bearings.

[92Excel]

Thanks for your efforts tryan. Hard to talk about it when she's sitting in the garage and going from memory. Ever here of the springs in the damper plate wearing out and the overrun creates the "scream." And when I say scream it is a really loud screeching coming from the floorboard area. It doesn't last long and can be a little intermittant.

[92Excel]

...ever hear, rather, I will change the oil, etc at season start and see what that does.

[tryan]

the weak springs on my flex plate 'slip' just 10 degrees or so when i stomp it, but never a squeal or scream. i hope all is spinning at the same speed.


suck a little tranny fluid out and pour it through a paper towel. see if you can see any brass particles. the clearance on the disks is set by using c-clips of different thicknesses. it might be time for a thicker c-clip.

does the shaft spin a little when the tranny is cold and it's in neutral?

[skinautique]

If the shaft is spinning when the throttle isn't engaged then the plates need replacement inside the tranny. You can also get a whining noise from the Vdrive is the fluid level is low. There is a High mark and a Low mark. Check that one out and it may solve your problem and it is very cheap to add the oil! I have seen it happen before. Keep us posted.

[92Excel]

Thanks everyone. I will as soon as the water warms up. . .