Borg Warner Velvet Drive transmission issues / trans cooler

[milner351]

Hello

New here, but been working on this boat for years
- '86 kevlar classic comp.

As many of you have learned I'm sure, the older supras were prone to cancer in the floors and stringers. :(

My boat has all new epoxy/glass/wood wherever there was rot - which required all new floors, partial stringer replacement, etc, etc.

I finally finished all that and got the boat in the water for this 4th of July.

The boat was very dependable and pulled well - even impressed a few nautique owners. Save for a starter failure - all was well (replaced the starter with the new style from dbstarteralternator.com for cheap)

Then - the transmission started slipping when trying to pull up a skier.

Checked the fluid - BAD - it was dark gray, smelled a little burnt and appeared to be over full - and there was some foamy / milky film on the underside of the dipstick.

I ordered a new trans cooler from skidim and got it installed last night.

I put in the recomended 1.3 quarts of dextron 3.... so far so good, I plan on pulling this fluid out (mightyvac) and replacing with new a couple of times to make sure i got all the old stuff out ---- as recomended by skidim.


Has anyone else had this issue? :shock:

Is the trans on it's way out? :shock: :shock:

Has anyone rebuilt one? I have the manual from skidim, doesn't look too too bad.

[ACF]

Hi,
Kind of new here myself, but have fooled around with boats and cars for about 40 years and know a few things useful. Your comment: "appeared to be over full - and there was some foamy / milky film on the underside of the dipstick" strongly suggests water had gotten into the transmision. The good news is you probably caught it soon enough to save the box. With a boat this old, I would check the rear seal on the transmision shaft. It may, or may not show obvious signs of a problem, but if it is leaking you will probably see something on the shaft. I suspect all was fine, until you shipped enough water into the bilge for infiltration into the transmision. Replacement, if that is what you need to do, will involve uncoupling from the prop shaft, pulling out the seal (they make a tool for that), cleaning the flange, and gently (very) tapping a new seal into place (they also make a tool for this, I sometimes have used a short piece of PVC pipe). You will want to wipe down the rubber lip of the seal with some clean transmision fluid before the install.

[milner351]

Thanks for your quick reply.

I'm a mechanic turned mechanical engineer, been playing with all things mechanical since about '86 when I got my first real set of tools.

I have seen no signs of a leak in the bilge.

The only residue I have in the bilge seems to be coming from the breather on the valve cover - not sure how to seal that up any better save for getting a new rubber / paper gasket for the breather twist connection into the valve cover.


I think the water / atf met eachother in the trans cooler itself - not through a leaking output shaft seal - though that is not out of the question.

My bilge has been quite dry since I launched the boat - so I think the output shaft seal can wait for another day.

I just hope the clutches in the trans have survived this and after a few flush and fills will be ready for many more hours of service before requiring a rebuild.

[knoxsupra]

Milner351, I have rebuilt my transmission and let me just say what a pain. Most of the difficulty is removing the tranny as it is surprisingly heavy to remove from the bilge area of the boat. If your not seeing any fluid in your bilge which would deffinately be noticeable then I think your okay. The guys at skidim are awesome and an excellent resource. get yourself a repair manual and a little mechanical ability and you should be able to rebuild the transmission in about 8 hours. If you need any advice during the process let me know.