99 21V transmission

[Yokes]

My '99 21V (350 mercy Cruiser MPI) black transmission and V drive, the transmission started to slip while wake boarding this weekend. Only the second time out this year. It had the fluid changed at the beginning of the year last year and was a about half low on the stick by the end of the year. Topped it off before storage.

Ran good a couple of weeks ago and yesterday it started slipping. I checked the level and it didn't even appear on the stick. I refilled it and we went out for an hour and it started slipping again and was Hot, very very Hot. I put it on the trailer now.

Does anyone know about what a new transmission will run me for this boat or have anything else I should look at before going with a new tranmission?

[Cubby_Z]

Is the fluid milky? You could have a leaky transmission cooler. That would cause your fluid to get milky, not shift right, and run hot...Just a thought.

[Yokes]

Couldn't have told you if there was water in it. It was pretty much bone dry. I'm not sure where it all could have went in only 3 hours of running.

The model says velvet 10-17 004, is this the same as the velvet 71c on their website? Anyone know where to send to get rebuilt or to purchase new ones? I see eBay has some of the silver velvet transmissions pretty cheap are these different then the black, do the colors of the transmissions mean anything?
Has anyone tried any different ratios?
Does this separate from the engine/Walter V drive fairly easily? I'm wondering if i can tackle this myself or if I'm going to have to drop the 2-3k to have this done.

[ChrisSnow]

The oil has to have gone somewhere. If it's not in the bilge it probably went out the transmission heat exchanger. If you can even get a bit of fluid out to see if it's milky that would say a lot. The transmission might be fine and replacing it might not achieve anything. Plus a rebuild must be far cheaper than replacement if it came to it.


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[Mevs27]

Yes...I bought mine from a gentleman who bought it straight from the factory in 1999. At the end of the year he changed the ratios to a 1.46:1 transmission. (Yes you read that correct) He changed the prop and it was so sluggish. I just changed the prop after having the mechanic hook up the computer and told me the appropriate size.

[Thegerman618]

The common leaking point on these is small carbon seal on the opposite side of the shift linkage on the transmission. Run your finger across it and see if its oily, if it is either one or both O-rings in the shaft have gone bad, or the gasket/seal has gone bad or likely all 3 if that is where its leaking. That being said there would also be roughly 2 quarts of trans fluid in your bilge.

Next would be the heat exchanger, trans cooler, whatever you want to call it . Should have 2 trans lines going to it. Pull both lines from the heat exchanger makes sure they are clear of obstruction. Removed the heat exchanger should just be a single clamp and 2 hoses on either end holding it on. Run water through the end that connects to the raw water pump and see if you get any water coming out of the trans line holes. IF you do then your cooler is bad. Last would be to run trans fluid through where the transmission would connect and see if you get trans coming out where water would be. Again would be a second confirmation your heat exchanger is bad.

Check those then get back to us, but I would start by checking to make sure there is no fluid in the bilge and most likely is collecting in the notched point where the shaft seal is just FYI.

[boatwakes]

The trans cooler needs to have more than one pinhole in the bundle to exchange fluid and water, otherwise the fluid will disappear with the outgoing water supply. If its not in the bilge, the cooler took a dump. Clutches are probably fried but here's what you need to do:
- replace the trans cooler with new, refill the transmission and go run the boat under normal circumstances. If the tranny doesn't slip, you dodged a pretty big bullet. If it does, you need a new gear, some gaskets, an A-frame and a weekend. Report back and if you need to replace it, I'll give you the write up on it. Good luck..