Transom question for builders

[Ram4x4]

My hydro has an "adjustable transom", basically, a big slab of wood bolted to the back of the main transom. The idea, of course, is to be able to unbolt it, raise it up or down to change heights for different classes.

I don't like it. It adds a lot of weight to the rear and pushes the motor out a ways. So, I would like to fix that.

I've attached a rough sketch of the back of a hydro (sorry, it's not photo quality) . In the picture, the greenish area is the current shape of my main transom. The reddish brown represents what I am thinking of doing by taking that slab bolted to it, cutting it to fit and then epoxy it into position as shown. I would then epoxy a 3/16" plate of aluminum on the entire back and front side of the transom and add some small through bolts.

Do you think this would be strong enough, or would you completely tear out the transom and replace it?

[jsilvestri]

Do everything you mentioned but no need to export the aluminum plates. Just bolt the plates with 8 grade 5/16 bolts. Say four of them. It’s what I do to my transom for switching from mod to stock and back.

[DeanFHobart]

I’m assuming that this is going to be a permanent transom height and not adjustable. Do what Joe Silvestri suggested but also add some 3/8” or 1/2” wood dowel pins to the joints... butt joints need extra support. Epoxy the dowel pins in place.

[Ram4x4]

Yes, this will be a permanent height. I intend to set it to 300SSH height and then use a spacer when I need to run CSH.

I thought about a couple of steel or aluminum pins at the bottom and a couple thick counter sunk screws on the top outside end.

[baries]

Dean is right, no need for aluminum or steel dowel pins, several, say 3, 3/8 dowel epoxied in will hold just fine with the through bolted plates. Seal everything completely to prevent any water intrusion.

[DeanFHobart]

Yes, this will be a permanent height. I intend to set it to 300SSH height and then use a spacer when I need to run CSH.

I thought about a couple of steel or aluminum pins at the bottom and a couple thick counter sunk screws on the top outside end.

If you use steel use Stainless Steel (no rust)... but wood dowels should do the trick. And, yes, big wood countersunk screws on the top should do the trick also... use epoxy when installing them.

[Ram4x4]

Okie doke, thanks guys.

My main concern was if the arrangement would be strong enough to begin with (and I was hoping so, as I don't want to have to replace the entire transom). The 3/16" plates will be helpful to increase the thickness so I won't need a wood spacer to tighten my motor clamps down.

[pav225]

Call John Korbus. He sells slotted aluminum plates that slide up and down to accommodate CSH and 300ssH. Simply loosen 4 or 5 bolts, slide up the 2 AL plates, insert your spacer block, and re-tighten the bolts. Works very well.