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View Full Version : '86 Velvet Drive Trans Rattle Consensus...


peterb
07-07-2011, 11:37 PM
We have an '86 with a 351 and a velvet drive. Seems we picked up a new noise... a rattle that sounds like it is coming from the trans. We are leaving for a vacation on Lake Cumberland in early August and am worried that the "rattle" may cause some problems during vacation... when I can't get the boat easily out for service.

After reading the many threads on here, there seems some consistency then some non-consistency. So I thought I'd post my own and see what the general consensus is.

At idle, which is about 800 rpm, it's quiet. Shifting it into forward (idle) it drops to about 500-600rpm and there is a definite rattle. Bumping up the throttle a bit, the rattle goes away. At speed, no problems or sound either. Don't hear it in reverse, at any speed.

So, the questions are:
- This sound like a damper plate issue?
- Should I just bump up the idle a bit and live with it?
- Should I worry about failure (if I don;t chase it down or cheat and bump up the idle)?

Again, my big worry is the 5 days on the lake for vacation... don't want to ruin it for the 12 people going and counting on boat for fun. But of course, the other side of the coin, trying to save as much as possible in this tough economy.

Sad thing is, the boat is running better than it has in a long time now this.

Any suggestions....

thatsmrmastercraft
07-07-2011, 11:41 PM
I'm not the expert on this, but it sure sounds like a damper plate to me. I would pull the starter and look for pieces.

CantRepeat
07-08-2011, 06:26 AM
I'm not the expert on this, but it sure sounds like a damper plate to me. I would pull the starter and look for pieces.

I agree with Peter. More often then not the rattle is from older damper plates that have worn out springs. I've read threads of people have them explode before they were making noise and then some folks who drive the with the rattle for a long time before failure.

For less then $200 bucks and 4 hours of your time, I'd replace it.

03geetee
07-08-2011, 08:49 AM
I agree 100%. If you want to be sure your trip wont end in failure, get it fixed now and have piece of mind that its going to be good for years to come after that.

JTR

blakehardesty
07-08-2011, 11:06 AM
If it makes you feel better my 84 has done it since I bought it 2 years ago. What you described is exactly what mine does. I had it diagnosed by Culver Marina (My local MC dealer) and thats what I was told it was. I am still going strong on mine.

ski_king
07-08-2011, 11:42 AM
My 82 also rattles a little when it is ideling too slow. I adjusted the idle up slightly and the rattle went away.

Replacing the springs has been on my to do list for a few years now, but it seems to run fine and I have the theory of dont fix it if it aint broken.

CantRepeat
07-08-2011, 11:53 AM
My 82 also rattles a little when it is ideling too slow. I adjusted the idle up slightly and the rattle went away.

Replacing the springs has been on my to do list for a few years now, but it seems to run fine and I have the theory of dont fix it if it aint broken.

Until it lets go and you have a hole in the side of your bellhousing the size of baseball. :mad:

peterb
07-08-2011, 11:03 PM
OK so it sounds like the general consensus is to replace it before it breaks something worse. I suppose I can live with that. From what I have read, it's pretty straightforward once I get the part (I believe someone said SkiDim carries them).

For those that have done this, other than draining the tran, disassembling it, replacing the part, reassembly and refill... anything special we need to know, tips, tricks, tools, etc? I know when I did my vehicle trans once, we almost forgot to pre-fill the torque converter... don't want to miss any important steps. Hell, I am not even sure the best way to drain it other than put a bucket under the floor drain and let it pour into that.

Thanks for all the comments.

ProStar Slalom
07-08-2011, 11:19 PM
I'm pretty mechanically inclined, but didn't want to tackle this project when the damper plate in my '87 powerslot went out a few years ago. I took it to a shop during the week and was back on the water the next weekend. While the trans was out he replaced the seals, and I think I paid less than 500 for the plate, seals, and labor. In the middle of summer my weekend time and preventing frustration was worth paying to have it done..

dmminfla
07-09-2011, 07:04 AM
OK so it sounds like the general consensus is to replace it before it breaks something worse. I suppose I can live with that. From what I have read, it's pretty straightforward once I get the part (I believe someone said SkiDim carries them).

For those that have done this, other than draining the tran, disassembling it, replacing the part, reassembly and refill... anything special we need to know, tips, tricks, tools, etc? I know when I did my vehicle trans once, we almost forgot to pre-fill the torque converter... don't want to miss any important steps. Hell, I am not even sure the best way to drain it other than put a bucket under the floor drain and let it pour into that.

Thanks for all the comments.

The damper plate is bolted to the flywheel. There is no need to drain the tranny. All you have to do is remove bell housing from the motor and replace the damper plate. To do this detacth the shaft coupler, exhaust hoses, tranny cooler line,linkage,and remove the rear engine mount bolts, jack op the rear of the engine about 8 inches and pull the whole tranny and bell housing back far enough to remove the damper plate and replace it. I did my old 86 on the lift and it took only a few hours.

peterb
07-09-2011, 08:46 AM
Would it be beneficial to drain the tranny and replace the fluid... been a long time since it was done?

CantRepeat
07-09-2011, 08:59 AM
Would it be beneficial to drain the tranny and replace the fluid... been a long time since it was done?

Can't hurt.

03geetee
07-09-2011, 01:03 PM
Would it be beneficial to drain the tranny and replace the fluid... been a long time since it was done?

Our 83 is on the original damper plate, tranny, and all driveline parts with 2759hrs currently. The tranny fluid gets drained every year in the fall and refilled and checked often. Trans works and engages like butter. I recommend you start doing this, but dont be surprised if with the newer slicker fluid your tranny starts acting up. This happens when it is used to working with the older fluid with bits of friction in it, happens in cars alot.

Change it often and check it more, fluid is cheap trans are not.

JTR