72C trans question
 

WHy does the revese springs and clutches always break and come apart?

Good question,I have the first one I have ever been asked to work on sitting here and it has the same problem,Smitty

Too much throttle in reverse, shifting at too many RPM or else actually running the boat in reverse to go forward.

The standard driveline style only has enough depth in the housing for 2 clutches and many of the plug in style have room for 3 but are built with 2.

So we machine as needed and now build all our units with 3 reverse frictions. Also we have special reverse plates that are made with a better steel core.

We still see it, but far less often.

How about Machining the the foward gear outer plates (the pressure plate and rear plate) to accept 9 disks do about or can you only machine enough to get 8 on the input shaft gear. I was talking to a guy who top notch about these he told me about the machining for 8 but i didnt ask about 9.
-Mike

Oh also to add i do have 3 frictions and 2 steels on the reverse with 11 small springs against the pressure plate. Ive also seen the carbon fiber cluthces.
-Mike

I'd guess if you are breaking the reverse springs and clutches, adding more forward plates isnt gonna help. Something else is going on. The 72C is a reliable tranny. Most of the problems ive seen with them is blowing out the front pump seal, or smoking the clutches from running fluid low. Know several people who blew out the front pump seals for some odd reason the past couple summers.

Any idea why that happens mark?

The core material made the biggest differance in reverse. Yes, the seal problem is common, we have a fix for that also but it is only part of the transmissions we do in house.

Can i just cut the pressure plates to make a 9 disk or is there other parts needed/modified to do it? Longer clutch gear on the input shaft and so on......
-Mike

Any help on making a 9 Disk? do i need a larger clucth drive gear if so do you have them?
Thanks
Mike

If you do a search out here i posted a name of a company that is happy to help you do it yourself and sell you only the parts you need. They will also make the mod for you if you want to go that route... but you wont get a shinny new sticker for it :(