Older Velvet Drive - Fluid Selection

[Pra4sno]

'93 Echelon with Borg Velvet Drive.  What interval do you change fluid based on time in service as well as hours, duty type.  What fluid have you had the best results with?

 

I'm at 100 hours on 10 weight hydraulic tractor oil.  Pulled a sample yesterday and it still smells fine, looks barely off-tint.  Engagement is really good - still slips into gear smoothly, (no slamming even when going from forward to reverse close together) and trans stays cool even when pushed. 

It's getting harder to find the tractor oil in anything less than 5 gallon buckets, and that is more than I will need in a lifetime.  

My understanding is that Dextron II is fine, but spoke with an older ski-boat 'guru' about a carb rebuild I'm doing and when I mentioned switching to modern ATF he said the old hydraulic fluid makes a big difference in the "hit" felt when shifting in and out of gear on the velvet drives and can result in rough engagement.

[Woodski]

@Pra4sno - The VD is bulletproof for starters.  Fluid can go a long time,  so not a panic to replace.  100+ hours seems a non issue.  As for fluid, stay with hydraulic fluid, your 'guru' is spot on.  I ran 'the test' and gave ATF a shot, went back to hydraulic fluid.  The ATF allows the transmission to clatter at idle speed and have a less smooth engagement.  Part of the'velvet' should be attributed to the hydraulic fluid.  I got Mobil online in a gallon container.

[Pra4sno]

15 hours ago, Woodski said:

@Pra4sno - The VD is bulletproof for starters.  Fluid can go a long time,  so not a panic to replace.  100+ hours seems a non issue.  As for fluid, stay with hydraulic fluid, your 'guru' is spot on.  I ran 'the test' and gave ATF a shot, went back to hydraulic fluid.  The ATF allows the transmission to clatter at idle speed and have a less smooth engagement.  Part of the'velvet' should be attributed to the hydraulic fluid.  I got Mobil online in a gallon container.

Appreciate that, it's inline with what I figured.  Will look for the mobile - thanks for the tip.  I don't have room in the garage for another 5 gallon pail!  

This transmission truly is a beauty.  

[Woodski]

It is a nice unit, only downside is the weight.  Much heavier than the ZF and PCM units.

I found Mobil 423 online in a gallon container, works great.  Also good options from Chevron & Citgo.  You can get hydraulic oil at TSC also, their brand and I couldn't find much data on it so I went with the Mobil.

[Pra4sno]

@Woodski We've been running the boat a bit more this year and think its time to get some fresh 10wt in.  I did some research on bobistheoilguy and found the comp. spec to 10wt is ISO 32.  

I'm finding some great ISO options, particularly a really easy to source Powercare AW ISO 32 by the gallon for only $15.00.  It's non detergent, which I was having a difficult time finding this stuff without detergents.

 

On another note, I think its going to be the season to replace my alternator.  I've been putting the boat on a battery maintainer when we're not going to be using it for over a week, and quickly noticed it was firing easier after I had left it on the maintainer.  I installed a battery disconnect when I relocated the battery to the bow so I know its not a parasitic drain.  Battery is new and I've tested it - holds a charge at 12.85 volts.  

I believe I've got a regulator going out.  All of my grounds are good (pulled and sanded them to verify) and no bad wires.  Its the original alternator from '93 and I'm hearing a little bit of chirping from it - likely a bearing.  Tested its output at 12.6-12.8 so its just not topping the battery up.  

Its great news though because I've been fighting hard starting for two years.  Replacing the ignition coil made it SO much better, but having a fully charged battery is insane.  It fires immediately every time, when hot or cold.  Now I have a carb rebuild kit sitting in the garage to mess with over the winter, no need this year it seems.  

ANOTHER thing I have been really happy with was the upgrade to the 525 prop.  The wake is vastly different and much better to ski.  Short line (which I suck at) is almost zero wake, and 15-22 off is down to a single bump that's noticeably softer and less ramped.  Further weight reduction is on the docket, as is putting another 50 lbs in the bow to get the front end down.

Edited August 21, 2020 by Pra4sno

[Pra4sno]

Here is the stuff I'm looking at for the 10 wt "tractor oil".  If I'm remembering right, Borg specified detergent free to prevent emulsification.  

https://www.homedepot.com/p/Powercare-AW-ISO-32-1-Gal-Hydraulic-Oil-66783/206522259