Hey guys.

I’ve got a couple of spare BW 72C’s here that I’m going to refresh. The first one was original to the boat and the other is a spare that picked up from Mike Mello (still in the crate - supposed to be good).

The original collected some water so unsure of what the insides really look like. Has been sitting for five years. The seal blew a hole on that one so I’m suspecting the pump went bad. I removed the pump - showed some scratches so guessing it ate itself hence the blown seal. I removed the rear clutch assembly and it looked new. Thinking I’d disassemble completely, clean it up, put in a rebuild kit, and replace the pump.

The other has clean transmission fluid and looks great overall. Thinking I’d get a gasket kit for it and a fresh pump and maybe use that one now to replace the leaking one in the boat.

I’ve redone some 727s in my time but has been years. They’re very simple looking from schematics and videos I’ve seen and I have all the tools and a press to do the job… don’t have a way of testing until it goes in the boat though.

Any advice to give or tricks that I can apply to these while I’m redoing them?

Nobody?

I looked at the one in the boat and ran it while adding some fresh fluid to it. It seemed like the leak subsided some. I'll run it on the hose again tomorrow to see if it's cooperating. Maybe it can make it through the summer?

In the meantime, I'll be rebuilding a couple of transmissions.

Here's my step by step on how I rebuilt my transmissions.
1. Remove transmissions from boat
2, Load transmissions into reliable vehicle
3. Transport transmissions to repair shop
4. Wait 3 days and return to repair shop
5. Throw $money$ at owner of repair shop
6. Load repaired transmissions into reliable vehicle
7. Transport transmissions back to boat
8. Install transmissions in boat
9. Add fluid to repaired transmissions
10, Go boating and not worry about transmissions
The End...

What HP are you looking for?

Have you got a 72C service manual?

Indemar
https://indemar-wip.squarespace.com › ...PDF
Service Manual - 71C -72C Direct Drive

If you jack up the pressure, 20psi is the suggested increase. But harder to cool, and uses more HP.
​​​​

Simplest transmission I’ve ever had apart.

With that being said, I am tempted to get it done versus dicking with it.

I have the 71C/72C manual from B/W.

Needs to handle 600 lbs ft / 600 hp.

Not sure I’d increase pressure but shaving some plates and adding an additional friction and plate wouldn’t hurt.

Need to find someone that does these rebuilds here in Tidewater. Parts are easy - eBasic Power has the kit and pump (good parts, not junk) for under $500 and I can have in a day.

I like the idea of doing my own stuff, and like I said I’ve built a few 727s and a couple 904s (loved me a 727, Turbo Action manual valve body and a 8-inch “J” converter back in the day). These two are cakewalks compared to those.

But I’m also swamped at work and free time is at a major premium - if I could trust someone to yank it all apart and replace/put it back together, I’d be game for that, too. Maybe.

EVERY
SINGLE
TIME
I opt to pay somebody to do a good professional job/task for me I end up disappointed and full of rage.
I cross my fingers and hope you find a guy who will do a good job for reasonable money in the agreed timeframe.
But
I would bite the bullet and do it myself unless you think you've found the right guy.

MC

I hear you on that one!

I’ve already got the original one most all apart on the bench. Pretty simple. Trans fluid isn’t one of my favorite things though.

No offense to the ones that build these for big power but have to wonder why the subject of working on these seems to be so quiet.

I tore mine apart and made one good one from the best parts of 3 transmissions i had, with new bearings, seals and clutch plates.. Not difficult, and I had very little experience with transmissions. One thing i did, having seen it on a ski boat forum, is put a 20% larger forward clutch piston in for more clamping force. Anyone heard of doing this? It does not seem to be a common mod. My application is behind a Cummins 6BTA so was worried about torque being over the rating for the 72C. So far it has performed flawlessly.
By the way, i bought what was supposed to be a rebuilt trans. It was not.

Where did you find a piston? Any more information?