KAAMA

You are right. I left out the word "Merc"...we usually refered to them as the old "Merc trannies" or "Merc TRS trannies"

White Knuckles

Boat is 1981.

I have the Merc Transmissions.I have about 525 HP in each 502 engine. I did notice some liquid splatter on the back wall of the bilge behind the engine, but I will not get a chance to get back there and get a good look until Friday. I will take some digital pics, and post them also. I have not decided yet whether to rebuild the Mercs, or upgrade to the Borg Warners. Do the bw trannys require any modifications from the Mercs when upgraded?

Also, I have been told by some that the engine has to be pulled, and others have told me that they can switch them without pulling the engines?

Thanks again

MOBILEMERCMAN

The up grade will be worth it in the long run. It will probably slow you down a bit though. Borg warners are longer and will require moving you engine mounts forward about a foot and will need to change input shaft on drives. There are other up grade directions to go as well. Motors will end up coming out. The guy that said he could change a merc trannie without pulling the motor is mistaken.
Jim

KAAMA

The BW tranny is a longer tranny...therefore, the engines will need to be moved forward if you go from the Merc tannies to the BW.

Anytime we had to rebuild an old Merc Tranny we always pulled the engines...it just made it a lot less aggravating. If I remember right, I may have had a friend who pulled the BW trannies out of a boat without pulling the engines. I guess no matter what tranny you have it will depend on the design of the boat and how it was rigged before determining if a tranny can be pulled without pulling the engines.

MOBILEMERCMAN

Kaama, is right pull it, whether his friend actually removed the motor or unhooked it and moved it forward and layed it in bilge it ends up being the same work. I think its easier to pull complete and don't disrespect the boat.
Jim

White Knuckles

Thanks again guys. I will keep you informed. I will probably end up running it over to Craig Colabella as he does most of my maintainence on my boats.

Audiofn

There is a LOT to changing over from the Merc Trans to the BW. I will try and remember everything that I have been buying. You will need:

1) BW transmisions.
2) Tranny coolers
3) New hoses for the tranny collers and so on
4) Move the motors forward (make sure that you have the room in front of the engines and around the engine hatches)
5) New starters
6) Extend your exhaust
7) Different yokes for the drive
8) More then likely will have to rewire for the starter

I think that I am missing a few other things. Is it worth it? Only you can answer that. The only reason that I am replacing mine is that I am going with blower motors and Konrads. I put brass clutches in my Merc Trans and a few other mods and they should be good for a bit of power. The week part in those trannies is ussually the oil pump gear.

jeff1000man

You have to be a really BIG MAN to get one of those trannies out of a boat without pulling the engine. You are going to spend a lot of time and money if you do the upgrade.

you can buy the BW trannies new. You can't get the plug in tail stocks anymore. Guys that have them hold on to them pretty tight. Last one I bought was $450. That was after the $1200 I spent to upgrade my existing tranny.

You can plane on around 5-7k for the parts to do what you are thinking about doing if you don't have friends with these parts laying around, or you can spend all winter on ebay like the rest of us and stockpile the parts as they become available.

You can fix a lot of merc trannies for that money. I see the merctrans on ebay all of the time. You could just buy a couple spares for not much money.

jeff1000man

http://cgi.ebay.com/ebaymotors/mercr...spagenameZWDVW

KAAMA

Yeah I agree! If my memory serves me right my friend had a chain fall/hoist hooked up to the tranny to lift it out. That BW is one heavy piece, but this was such a long time ago (early 80's) I cannot remember. Actually, it may have been the center engine's tranny on a tripple engine application...the boat was a 1983 37'7" Scarab. Other than that we always just pulled the engines with trannies, etc---just made things much easier in the long run.

Expensive is right....it took a lot of $$$ and labor involved just removing my TRS drives and trannies and go to a Bravo drive set-up---of course the availability of parts was not an issue either.