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transmission noise problem velvet drive 71/72c

T

thelasthour

Member
I’ve got a Borg Warner velvet drive 72c 1.88 (Its possible it is the 71c, I don't remember) coupled with a crusader 5.7 300hp engine. On the last trip out when stopping at a fishing spot after putting it in neutral and then back in gear I hear a sound coming from the tranny. I checked the fluid and did not get a reading on the dipstick. The noise sounded “clackety clack, clackety clack etc” the sound disappeared in neutral and was present in fwd and reverse. The boat would still go into gear fine. After returning to the dock on one engine I filled up the tranny with ATF and the sound disappeared. On the next trip I made it out about 2 miles and stopped the boat to listen for the sound and it was back, but a little quieter. I returned to the dock on one motor again. After checking the fluid level, it had not leaked at all. On a 3rd trip to diagnose, I could not get the noise to return while at the dock running in fwd and reverse, but I did not run it outside of the dock. I’m confused. Could something change when the tranny gets hot? Does a dampner plate exist on this transmission? The transmission is not slipping and will perform fine at all speeds. I only notice the noise at RPM’s below 1500. Any help would be appreciated. Also, is there any repair facility recommended that would service NW florida (Steinhatchee,fl).
 
You will need to make sure your engine is running on all eight cylinders. You will need to check this manually not just by listening. On dead cylinder will make this transmission noisy.
 
To answer a few questions, yes there is a dampner plate between the tranny and engine. Velvet drives can make a little noise at low RPM's as this is just the nature of the beast. Hopefully you did not over-heat the trans by running with low oil level. I would make sure there are no obvious leaks, fill with fresh fluid, and run it again to see if the noise is back. If no noise and everything is working, I would not be concerned.
 
I'd be inclined to find out where the fluid went...loss of gear fluid is not normal and the leak may suddenly increase when you least expect it.

Like most gears, low oil will induce all kinds of anomolies and noises - hopefully you didn't damage anything running it under load with low fluid.

2X on Chris' suggest of looking for the dead cylinder...that is one of the most common sources for "gear noise", especially at lower RPM.
 
Check my posts on the Crusader forum back in April/May. I had a very similar problem, I ran one of mine w/o fluid after changing my hydraulic lines and getting a false reading. My noise gradually went away over the course of a few days and topping off the fluid. I've put about 40 hours and it's been fine. The general thinking was I heard a cavitation because of the lack of fluid.

But, I knew what my issue was and what accounted for the low fluid.
 
Hello all. New member here. I came across this thread after searching about problem I am having with my boat
i have a sea ray 340 sundancer w/ twin crusader 454's coupled to Borg velvet drives model 10-05-011 which appear to be 72c 1.51:1 ratios v drives. I have a clacking sound coming from the starboard tranny/v drive assembly. It sounds like a loose nut in there bouncing around inside the housing while in gear forward or reverse. Does not do it in neutral. Fluid is at the correct level, looks clean, no metal, and does not smell burnt in any way. Talking to a few guys they felt it was the tranny/prop shaft coupler making the noise. Disconnected the coupler and still the same noise. Can't pinpoint between the tranny or vdrive assembly. It still shifts as smooth as can be. I read above about a low idle condition causing this but from what I recall the idle seems correct and I think I remember it doing it while underway at say 1500 or so rpm. That makes me think it isn't an idle problem. Just wondering if anyone can shed an light. Getting ready to have the marina pull the boat and then the motor to get the tranny out but would really like to try and diagnose it first if possible.


Thsnks
 
Merc1100sc said:
Hello all. New member here. I came across this thread after searching about problem I am having with my boat
i have a sea ray 340 sundancer w/ twin crusader 454's coupled to Borg velvet drives model 10-05-011 which appear to be 72c 1.51:1 ratios v drives. I have a clacking sound coming from the starboard tranny/v drive assembly. It sounds like a loose nut in there bouncing around inside the housing while in gear forward or reverse. Does not do it in neutral. Fluid is at the correct level, looks clean, no metal, and does not smell burnt in any way. Talking to a few guys they felt it was the tranny/prop shaft coupler making the noise. Disconnected the coupler and still the same noise. Can't pinpoint between the tranny or vdrive assembly. It still shifts as smooth as can be. I read above about a low idle condition causing this but from what I recall the idle seems correct and I think I remember it doing it while underway at say 1500 or so rpm. That makes me think it isn't an idle problem. Just wondering if anyone can shed an light. Getting ready to have the marina pull the boat and then the motor to get the tranny out but would really like to try and diagnose it first if possible.


Thsnks
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You will need to make sure your engine is running on all eight cylinders. You will need to check this manually not just by listening. On dead cylinder will make this transmission noisy.
 
Docksidemarineservices said:
You will need to make sure your engine is running on all eight cylinders. You will need to check this manually not just by listening. On dead cylinder will make this transmission noisy.
Click to expand...
Thanks for the quick reply. I will check this. Also, assuming all 8 are running but the idle is low and causing the noise, should the noise disappear under some throttle?
 
No assuming. Make sure you are running on all eight first. If it is not running on all eight at idle it will not be running on all eight off idle. If it is running on all the holes, possible broken/cracked, plate/coupler.
 
Docksidemarineservices said:
No assuming. Make sure you are running on all eight first. If it is not running on all eight at idle it will not be running on all eight off idle. If it is running on all the holes, possible broken/cracked, plate/coupler.
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OK. Was at the boat last night. All 8 are running. Boat idles at about 600 rpm. Put the boat in gear at idle and I get the noise. Rev it to about 700 rpm and the noise goes away. Is this a symptom of the dampener plate? Thanks
 
There are no assumptions in Marine repairs. If you bump the idle up and the noise goes away, good. If it comes back after a while of running, then you need to think about pulling the trans.
 
Docksidemarineservices said:
There are no assumptions in Marine repairs. If you bump the idle up and the noise goes away, good. If it comes back after a while of running, then you need to think about pulling the trans.
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If the noise goes away with the idle increase my plan would be to run it theirs season and inspect after the season as this would more than likely require the motor to be pulled due to the tight fit.
 
Hi, my stbd Velvet Drive model 20-01 004 [direct drive on a Crusader 350XL] is clanking in idle, fwd and reverse pretty loudly. I checked ATF fluid for clarity, aroma and level, all of which seem ok. I will check that all 8 cylinders work tomorrow, but reading through the above comments, what does it mean to have the clanking sound even in idle? The trans works flawlessly in and out of fwd/idle/rvrs, and I'm planning on taking a trip this week unless I'm in jeopardy of doing some real damage. Thanks, Tom.
 
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tommyfmu said:
Hi, my stbd Velvet Drive model 20-01 004 [direct drive on a Crusader 350XL] is clanking in idle, fwd and reverse pretty loudly. I checked ATF fluid for clarity, aroma and level, all of which seem ok. I will check that all 8 cylinders work tomorrow, but reading through the above comments, what does it mean to have the clanking sound even in idle? The trans works flawlessly in and out of fwd/idle/rvrs, and I'm planning on taking a trip this week unless I'm in jeopardy of doing some real damage. Thanks, Tom.
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No expert here but from what I have learned on this forum and from other sources, if your idle is too low it will clank in forward or reverse. My idle was at 600 and it clanked. Turned it up to 700 and it stopped.
 
Merc1100sc said:
No expert here but from what I have learned on this forum and from other sources, if your idle is too low it will clank in forward or reverse. My idle was at 600 and it clanked. Turned it up to 700 and it stopped.
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Thanks for the reply; what has me more baffled though is it clanks in neutral as well. I will check the idle again. It was down around 500, and since I stalled Friday [not fun on a windy day] backing into my slip, I raised the idle on both engines, although not quite to 700; will try and see if it helps.
 
tommyfmu said:
Thanks for the reply; what has me more baffled though is it clanks in neutral as well. I will check the idle again. It was down around 500, and since I stalled Friday [not fun on a windy day] backing into my slip, I raised the idle on both engines, although not quite to 700; will try and see if it helps.
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Mine did not clank in neutral but my idle was never that low. And, to be more specific it was more of a grinding kind of sound. Kind of like a transmission not fully in gear and the gears grinding. I found mine to be coming from the dampener plate area. There should be an inspection cover on the top of the bell housing area that you can remove and get more sound out of. I was able to look in there with a bore scope and make sure all the springs on the dampener plate were in tact and "looked" good. I'm not sure of a better inspection technique without having to pull the motor due to the limited clearance of the v-drive assembly in my boat.

Again, the sound completely went away with an increase in idle. I think,, but am not sure, if the dampener is bad, you'll get sound regardless of idle adjustments.

See if your sound goes away in neutral just by throttling up to 700 rpm.
 
Merc1100sc said:
Mine did not clank in neutral but my idle was never that low. And, to be more specific it was more of a grinding kind of sound. Kind of like a transmission not fully in gear and the gears grinding. I found mine to be coming from the dampener plate area. There should be an inspection cover on the top of the bell housing area that you can remove and get more sound out of. I was able to look in there with a bore scope and make sure all the springs on the dampener plate were in tact and "looked" good. I'm not sure of a better inspection technique without having to pull the motor due to the limited clearance of the v-drive assembly in my boat.

Again, the sound completely went away with an increase in idle. I think,, but am not sure, if the dampener is bad, you'll get sound regardless of idle adjustments.

See if your sound goes away in neutral just by throttling up to 700 rpm.
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I just got a call from my marina's mechanic; no problem with the trans; culprit is salt water in my no.3 cylinder. Engine will have to be pulled to inspect ;-( Gotta love boating; b-o-a-t.
 
Docksidemarineservices said:
You will need to make sure your engine is running on all eight cylinders. You will need to check this manually not just by listening. On dead cylinder will make this transmission noisy.
Click to expand...


I'm sorry if this is a stupid question, but how do you check to confirm that the engine is running on all eight cylinders? I have the same issue with the chattering noise in gear at low RPMs.

BTW, DockSide, where are you based out of?
 
FastFred said:
I'm sorry if this is a stupid question, but how do you check to confirm that the engine is running on all eight cylinders? I have the same issue with the chattering noise in gear at low RPMs.

BTW, DockSide, where are you based out of?
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On top of the distributor cap, you pull off each wire one at a time to hear if the rpm's go down, meaning a loss of power. If a piston is firing, the rpm's should noticeably drop down [you can hear it], then put that wire back on the cap and it should rev up to where it was before. If you pull a wire and no change, then that one isn't firing. Caution: make doubly sure there are no fuel vapors in the eng compartment because arcing will occur between each pulled wire and the block. Second caution: wear thick rubber gloves or you're sure to feel the discomfort of 23000 volts.
 
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