Can anyone ID this drive?

Hello all,


Have not been able to work on my boat project all summer. I made a deal with myself that if I got my "substantial to do list" done on this three day weekend, I could start the boat.

Anyway, yesterday, I stopped by the transmission shop where the previous owner had left the transmission. (auto shop that knew nothing about a marine unit) I picked it up and brought it home. My wife was horrified, but I am hopeful.

It looked like a total wreck, but. The dipstick has clean oil on it and the shaft turns freely. It came off os a GM350. I will not need this bell housing, starter etc. so its no loss.

I would like to know what it is first. Then I can figure out if its worth rehab. It may not be what I need. I got the new "to me" engine yesterday too. 2004 24 valve 245hp stock Cummins Turbo Diesel. It will have lots of torque, so that will need to be planned out.

Input welcomed!

Thanks, Chris

 

Next Observation

It appears to be a AS171c?

I was going to order a book from Borg on it, but. That poor thing is a rust bucket. I sprayed it many times today with penetrating oil. Scraped all the loose flakes off and it was starting to look like something.

But all the bolts are stuck tight. SAE don't fit and neither do metric. Maybe a bit of scale still on there. A couple are really degraded and will probably need to be drilled and tapped. The shifter has no hint of movement and there is a sensor housing on the opposite side that is hardly recognizable. The transmission cooler seems to be okay, but the water pump is rotted badly.

I'm thinking I will hunt for another one less degraded. I have read in other threads that they are not that bad to rebuild. And BW has excellent help to go with their kits.

As above, opinions and information about what your choice of this or different transmssion would be to go behind the 5.9.

Thanks, Chris

 

That's what it looks like. The 71 and 72 are very similar except for the size. All bolts should be SAE.

 

71C,s have a 4" dia coupling and the 72C, a 5" dia.

 

Velvets are easy to find..I have a stack of 71s and one 72 w/reduction sitting outside. I see them on EBay or in Boats and Harbors in good used condition for less than a thousand bucks all the time.

That 'sensor' is the neutral position/neutral safety switch btw.

Although not rated for anything close to it, I've run the 71 behind big block Ford gas engines without ever burning one up and the peak torque for a 370 HP Ford 460 is going to be very close to same as peak torque for that oil burner you have your hands on. By the Borg Warner book, however, I would bet a 72 would be the better match up. Too lazy to actually pull the book and look that up...but I'm not far off I'm sure.

 

The box shown is a 1:1 so unless your looking for top speed in a light boat you will need a reduction version

bolt flange to output flange overall length for a 71 versus a 72 is the best way to determine which you have
72C (10-18) 11.44 in. (290.58mm)
71C (10-17) 10.50 in. (266.70mm)

 

bummed

Thanks, That is true, there are lots of transmissions out there. I was trying to take your advice and find a factory marine engine.

I talked to BW today and it was a huge help. Even though my plans were crushed. My gear and prop room cant take the 5.9. He says I need a 1.75" shaft/bearing gear and an 18 inch prop. It has a 12" prop now. It would take lots of time and money to change all that over, and still not be sure of the end result.

For this project, Im going to go back with a gasser and get to fishing I think. Now he did say if I found a GM 6.5 turbo I could go with the same gear and a BW no problem. There used to be tons of those 6.5 in this region until today when I wanted to find one.

Gas and go?

Chris

 

I wouldnt touch a turbo GM6.5.
Although there may be millions around there are hundred of thousands with broken crankshafts/blocks
Nodular iron crank in a diesel just doesnt cut it

 

5.9

Well this is the pitts.

I wasted the entire day searching the internet for options. As I see it, I have 4 paths to choose from.

#1 Abandon this boat project and just buy a small aluminum boat cheap and stay in small water. Dont really like that option.

#2 Put a gas engine back in it and live with the underpowered sloth with high fuel consumption.

#3 Put an offshore bracket on it with outboards which was the first plan I had for it. The most expensive way to go. If I buy new outboards, I might as wel have just bought a whole new boat. Hmmmm?

#4 Keep with the 5.9 plan. I just need to find a source for 1.75" shaft and associated hardware. That has been a huge challenge. Not very much online at all. Most of the boats out here are I/O or outboards. The inboards are ski boats with 1" gear. This is my favorite option, if I can find the gear.