High Iron in BW Velvet Drive

[Eddieandgail]

I have 1987 Lehman 135s with 2:1 velvet drives with 2500 hours. Port tranny filled with water 18 months ago when cooler went bad. Removed tranny, had it rebuilt at my trusted local tranny shop where owner said he did a couple a year of those without problem
My first oil sample on rebuild at 100 hours showed 810 iron content
I changed the oil and My next one a couple weeks ago with 38 hours showed 790 so no better. Lab report believes gear wear and does show evidence of my recent oil change.
Runs smooth as silk no noises, shifts perfectly but can’t imagine what rebuilder could have done wrong.
Ideas please?
Eddie
47 Sea Ranger RPH

 

[C lectric]

Post the report. Not a summary as there may be other items of interest to point to a problem source.

 

[johnma]

You should ask your rebuilder for a list of parts he used. If he installed new gears the high iron may be nothing more than break in material. If you had bearing or shaft issues you would have high steel. friction material issues would be high silicone. If he didn't install new gears you may have an issue. I see you're in Maryland; Transaxle does several hundred of these a year in boats and construction equipment. Give them a call at 800-257-0444 and ask for the off highway shop. Ask one of their techs for an opinion. You can say you know me (John Malley) I was the off highway general manager for all of their U.S. and Middle East locations for 26 years before I retired last year.
John

 

[jleonard]

11 years ago I sampled my velvet drive (3400+ hours) and it showed 3000 ppm of iron.

ADC said tranny was toast as their experience said 300 ppm was rebuild time and I was at 10 times that.
Local Velvet Drive distributor said tear it apart and see.
So I did.
Clutches were shot, so I rebuilt the tranny myself (pretty easy).
What I found was in the bottom of the sump there is a magnet that is epoxied to attract all the iron particles. The magnet is not mentioned or shown in the manuals I have.
I determined that I had taken the sample from next to the magnet, hence the high iron. Local VD experts agreed.
Perhaps you have the same issue.
I would re-sample but keep the sample tube away from the sump bottom.

 

[Eddieandgail]

This was a rebuild due to being filled with water and was a basic rebuild of replacing clutches as far as I know. No metal parts replaced other than a thrust washer. This report is a total of 138 hours since rebuild. I’m willing to try a good flushing with a gallon of fluid to be certain it is not some kind of break-in debris but there were no new metal parts to break- in.
As you can imagine it’s a giant pain to get this out, and even less fun getting it back in cause I had to build a second A frame to support it to install. I also replaced damper plate per suggestion of Brian at ADC.
Eddie

 

[Eddieandgail]

Posted reply with a pdf. Does that not work?

 

[Eddieandgail]

Iron content

hopefully report shows this time

 

[Eddieandgail]

High Iron

Maybe clearer

 

[SoWhat]

Clutch plates are designed to wear. You will always have iron particles. The more shifting you do the more wear. Gears are massively over-designed in velvet drives so I doubt wear will become an issue at 2500 hours. If transmissions are running fine, change the fluid once a year and enjoy the good life

 

[Eddieandgail]

High Iron

Concern is jump from 50 to 800 so is that the new normal and if it stays consistent is that 100s or thousands of hours before gears have no teeth or whatever it is that happens to them. I will use til end of season then do another test before changing all the fluids before winterizing. Just concerned that, in the immortal words of Capt Ron, “if something is going to happen...it’s gonna happen out there”. As far as shifting a lot, of course I shift a lot. You should see me trying to dock this beast with a little breeze especially if I don’t use bow thruster.
Eddie

 

[diver dave]

Since you have two identical trannys, I would do these tests to both. Thereby ridding the experimental bias of "docking shifts" and "normal". Also, note you are getting "elemental" analytics. STeel is > 95% iron plus carbon and manganese. Notice Mn jumps with Fe; so, yes, likely a steel wear item.

 

[C lectric]

2nd testing the other gear for comparison.
I'm no expert but in addition to D.D. comment I noticed that the calcium , zinc and phosphorus are way down compared to the oil test in the first report.

THose items are often antiwear additives and in fresh oil should show much higher.
Which oil were you using in the first report? It simply shows as lube oil.

It does not appear in the next reports but rather ATF.
Which ATF? Are you using Dexron?

If you were using SAE 30 engine oil previously then maybe that might be what is needed to include the antiwear additives.

You might also ask for the TAN and TBN although it will cost you a bit more for those two tests.