Transmission rear oil seal

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RT Firefly

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Greetings,
It's time to change my leaking transmission oil seal. Velvet Drive CR2 drop shaft 2:1 reduction. The way I understand it is: Unbolt shaft coupling, slide shaft back, remove large nut, take off shaft coupling/flange, remove old seal, put in new seal, put flange back on...and here's where I'm stumped...
What is the torque specification for the retaining nut? Do I have to drain the fluid before I start all this? What's a good repellent for bilge ferrets? What else should I know?
Thanks in advance.
 
RTF--- I have on my computer desktop here a PDF of the shop manual for the BW Velvet Drive that I just downloaded. I don't know if it covers all three models but I'll be happy to attach the thing to an e-mail if you want to PM me one to use.
 
The torque spec for the straight through is 200 ft lbs. If the nut is loose that may be your leak not the seal. Use lots of rtv
 
Greetings,
Thanks Mr. Marin. I think it's just straight forward wrenching. Mr. m was kind enough to offer the torque spec' (don't have a torque wrench handy but 200 ft/lbs is a heavy grunt). I have changed oil seals in the past. Be careful, clean everything well, line up correctly and be gentle tapping it in straight.
So, drain first? RTV? Where? On the splines, behind the nut? Ugh, I hate RTV.
Since I have the seal and I'll have to take everything off anyway, even if the nut is loose, I'll change the seal while I'm at it.
See, here it is...
th
 
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Well RTF, that looks like a seal of approval.
I know a joke about what a walrus and Tupperware have in common, but it can`t go here.
 
Replace seal, slide on coupling, fill space around the shaft with rtv ( don't be stingy), put nut on and torque, have beer
 
Greetings,
Thanks Mr. m. Seal, coupling, fill, nut, torque, beer....Hmmm....sounds like I should be having a cigarette afterwords as well...
 
Greetings,
Final report. Took a whole day to find a 1 11/16" socket. Tried NAPA, Advanced Auto, O'Reileys, Lowes, Ace as well as a few other independent outlets. Finally, got one at Tractor Supply as well as a 2' breaker bar.
Some "rocket scientist" had attempted to tighten the nut with a cold chisel so out comes the trust Dremel to grind off the high spots which prevented the socket from seating firmly. Thanks to Mr. m, I knew the torque specification on said mangled nut was 200 ft/lbs. I suspect the cold chisel only managed to impart in the neighborhood of 30 ft/lbs. So it could well have been leaking due to a loose nut. I removed the old seal, cleaned the area well, tapped in the new seal, replaced the flange after running a Dremel wire brush over the sealing surface, gooped on RTV and tightened the nut a full good grunt (I'm guessing at least 150 ft/lbs if not better). I did have to snug up the stuffing box as sliding the shaft back and forth initiated a dribble. I'm now on the search for Dexron II to top up and test run. I'm tempted to drain the whole works and use straight 30wt oil which the installation manual suggest is acceptable if run under 3000 RPM. Thanks all.
 
Walmart has Valvolene Dexron III.

Ken
 
Greetings,
Mr. ps. Thanks. I just thought of an advantage of continuing to use ATF. Any leaks are a tell-tale pink as opposed to straight 30wt. Still considering either...
 
Greetings,
Mr. ps. Thanks. I just thought of an advantage of continuing to use ATF. Any leaks are a tell-tale pink as opposed to straight 30wt. Still considering either...

The dipstick tells me about a leak.....a spot on the bilge or pad doesn't bother me.....too used to it I guess.

Out of hundreds of trannys and tens of thousands of miles...knock on wood....trannys may drip...but at the end of a season....only a minor top off was ever necessary.

Most trannys I have run also go at least 5 years between oil changes.

Sorry but conventional wisdom and trannys just don't agree with my experience.
 
RTF-- While our Velvet Drive manual says engine oil is okay to use "in an emergency" it should be changed to ATF as soon as possible.

ATF to Dexron II standards should be very easy to find. Actually, we use the newer Dexron III now, which is backwards compatible with Dexron II. NAPA stores should have what you need if you're still looking for it.
 
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30wt is fine, but I'd stick with ATF. It's just more drag spinning that thick oil between the rev clutch plates. Any flavor of Dexron is ok, most quick marts have it.
 
Greetings,
Well my confusion lies in the seemingly large variety of Dexrons on the market. I don't want to put in "new and improved" or a different rating if it is going to cause problems. Will mixing the different "flavors" cause problems or will I have to do a complete drain down and start afresh? ...And I thought I was done.
 
I have read multiple OEM manual's and the more recent ones say 30wt is fine below the threshold rpm for foaming.

Real life experience with 30wt and trannys abuse while assistance towing has confirmed it's use just fine in my book. I would guess the tranny in my tow boat sees a workout every year like 30 years in the average trawler here.

As Ski pointed out..ATF may have a bit less drag..but 30 we is widely accepted where I hail from.
 
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Will mixing the different "flavors" cause problems or will I have to do a complete drain down and start afresh? ...And I thought I was done.

We use a newer version of Dexron in our Velvet Drives which works great. But I wouldn't mix different generations of Dexron without first checking with a reputable transmission shop that knows these transmissions.
 
IF you decide to change fluid type....
I was told that the fluid in the reverse cylinder will stay there unless you remove the pressure port plug (or gage) and turn the tranny upside down to drain it.

Can someone confirm or deny that?:confused:
 
My Velvet Drive manual says 30wt is "acceptable" it also says that Dexron is "preferred". Dexron is readily available and I'm not one to second guess the designers, so I use Dexron.

Ken
 
Doing the same thing on my velvet drive. Marinegears.com also recommended RTV. 225 ft lbs. I have a 10:1 reduction gear.

Getting the old seal out will be sightless, by feel.
 
While tightening the nut on the transmission output flange what keeps the output shaft from turning?
 
put a couple of old bolts in the flange jam them with a bar then tighten the big nut? worked for me

I did mine in a similar way also. I actually bolted a piece of slotted angle iron to the flange. I had the stock laying around so it didn't cost me anything plus I had mine out and on a workbench.
 
I did mine in a similar way also. I actually bolted a piece of slotted angle iron to the flange. I had the stock laying around so it didn't cost me anything plus I had mine out and on a workbench.

On a ski trip to Colorado from Maryland in a Volkswagen bus, we blew an oil seal that soaked the clutch requiring a seal replacement and a new clutch. We found the parts, parked in a shopping mall lot, dropped the engine to the pavement, rolled the bus forward, and started on the repair. We had tools along. All went well until we needed to unscrew a large gland nut holding on the clutch assembly. My friend had not brought along his lockup jig. The bumper had to be removed and was lying on the pavement. I noticed that the mounting points for the bumper looked to be about the same spread as the flywheel bolts so we simply bolted the bumper to the flywheel which, of course, created a massive lever which allowed us to get the gland nut off. Moral of the story? As suggested above, fashion a lever arm with holes that match your application, the longer the better.
 
Great story!


1983 Present 42 Sundeck
Twin Lehman 135's
✌️
 
Greetings,
Mr. c. Hmmm...rear bumper bracket eh? I guess you never jammed a socket between the lower engine stud and the ring gear did you. All the same, good thinking.
 

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