Dustin: You're traveling the same road I was down this last spring. In fact, I've been down that road TWICE, first with a rebuild of my old HBW-50 (big mistake) and second with replacing it by installing a TECHNODRIVE Twin Disc TMC 40 P transmission. I have a E32-3 (1987) with a M25XP. I didn't do the work myself but rather had the marina install the transmission for a variety of reasons that I won't go into here. The install did go OK with a few "bumps" along the way. Like I mentioned I did have a rebuild of the old HBW-50 and at that time a new damper plate was installed. The rebuild lasted about 15 months before the trans failed again for the same reasons. So when the 40P was installed I used the same damper plate, which was virtually new, and the yard also installed a 404A Drivesaver ($395) between the back end of the 40P transmission and the shaft plate. They did this for two reasons. First the bolt pattern didn't quite line up and if I got tangled up in say, a crab pot line which could stop the shaft from turning, then the Drivesaver would destroy itself and save the transmission and engine from a sudden stop under power. It also helps smooth out the ride a little bit. Well, worth the money, IMO. The ratio was 2:1 but not sure about reverse.
The other hitch was that after the 40P transmission was installed it was impossible to pull its transmission fluid dip stick out because the heat exchanger was in the way. The old HBW-50 had its dip stick more towards the side but still was always a problem for me gettin it out. the 40P has the stick on the top of the transmission. After considerable thought I designed a bracket which included modifying the original HX bracket to raise the HX up and to starboard giving me enough clearance to pull the stick. I also took the time to clean the HX inside and out. The engine also needs to be raised about 1/4" which the yard did at the engine mounts. Here is a link to my original posting about my transmission problem:
http://www.ericsonyachts.org/infoex...blems-again-The-Saga-Continues&highlight=saga
You may have already read it but I suggest going back and reading the posting on the tail end where I document my solutions which included some photos. The 40P worked well this past season and even "felt" better then the original HBW-50. I found it on eBay (brand new) for $1,1980 from Sound Marine Diesel (
www.SoundMarineDiesel.com) who were very helpful with install and operational info. You're going to also have to buy a new transmission cable bracket ($60, I think) because the shift arm is located on the port side as opposed to the HBW-50 which was to starboard. Good luck!