I bought a counter rotating TR-drive by mistake, can it be a problem?
 

My current TR-drive is in a bad condition due to corrotion and there is also a crack along the bottom of the outgoing propeller shaft.
I decided to buy a better used one and found one in much better condition. When I got home and compared it to my old one I found that the rotation direction was different. Of course stupid not to check it out, but I never thought of it.
Now the question is what to do:

1: Can I run the boat with the counter rotating drive without doing anything?
The prop was slightly bigger so I do not know how the boat behaves.

2:Can I run with the counter rotating drive with my old propeller.
In this case, I have to change direction in my Merc Trans II transmission and can that cause problems?
Is the Merc Trans II stronger in one direction of rotation, ie, forward or does it not matter?
The boat is a Sea Ray 255 Sedan Bridge -81


Guide me Please :-)

// carla

no, you can't run in reverse to go forward. if it came with a left-hand prop, try it and see how boat is. cheapest alternative is buy a LH prop the right size-pitch for your boat. leftys are cheaper than RH on ebay. last but best choice is take drive apart and put the gear on the front of the propshaft facing back. right now it is on the back facing forwards. this is a single engine boat, i assume?

Hello and thank you for your answer "dereknkathy !"
Yes it is a singel engine boat. Do I understand right that I can change the rotation internally in the drive without putting new parts in ?

// Carla

the diff in rotation is the drive is built as if it were an alpha in reverse. with driven gear behind the vert shaft. same gear, diff location. it has to be reshimmed if you redo it, but any drive guy should be able to take care of it. TR? or TRS? you can also shop around for an empty case and have your bad-case guts put into it.

Thank you again. I think I will try to put the drive on the boat and test. If I have luck I will not feel anything different with the counter rotation.
// Carla

As mentioned, you don't want to run the trans in reverse. I'd get a left hand prop and try it. I f you wat to convert to rh, you'll need a new prop shaft and breaing to change the gear location (behind the pinion)

Konrad makes a direct bolt-on for the TR if interested.

Kurt

Won't cost anything to try it with the slightly larger prop and certainly won't hurt anything. If you don't like that find a left hand prop comprable to your original prop. If your dead set on it having right hand rotation then have the parts from your original lower unit switched over to the new one but that's going to cost you several hundred dollars. I don't think your going to see any difference with it being left hand though.

This is very embarrassing ... But I looked into it closer and now realize that my old drive was the counter-rotating and the new drive is the right. Strange because my last boat also had a counter-rotating TR-drive. Therefore, I thought the old one was right. But what a relief, then I dont need to worry more, I will put the new drive on the boat and hopefully it will work even with a larger prop. Thanks everyone who has been involved in this, and thanks for a very great forum. / / Carla from Sweden.

the actual prop rotation on a single engine boat is-was only really an issue docking with a fixed shaft. they moved the drivers side to the right because with RH rotation, the boat pulled right in reverse. made it easier for driver to see dock. with outdrives it is a totally moot point. your boat proves this. you didn't even know you had "wrong" rotation.

Hi ! I guess it is an old myth then that the boat would lean if your drive rotation is the same as the motor rotation.
As you say "dereknkathy" I had no idea that I had a wrong rotation and this boat has behave as any boat I have had with right rotation.
What about the gear ratio on TR-drive, they are all the same or ? Someone told me it could be different ratio on different TR-drive. He is very wrong or ?

//Carla

i don't know if there are diff tooth counts in TR drives. turn input shaft and count prop turns. compare it to your existing drive. they are probably both 1.5 to 1 reduction.

Standard TR drive is 2:1. They did make a TR Commercial drive which was 1.5:1, however their rare and I have never even seen one of those before. The TRS is 1.5:1. As mentioned turn the input-ujoint shaft and see how many times you have to turn it to make the prop shaft turn one revolution. Something else this will tell you is if the input shaft turns the same direction as the propeller shaft it is a left hand rotation drive. If they turn opposite of each other than it is a right hand rotation. Just curious, exactly what size and type of boat is this on? What engine?

it is a 1981 Searay 25 foot Dancer with flybridge. i believe this would be a TRS, not a TR, and Carla is mistakenly leaving the S off. TR is a houseboat drive. i doubt many were put on 25 foot weekenders.

Not many true, but I have seen them on old Searays that weren't even that big and not weekenders. Carla could verify this by posting the propeller diameter or gear ratio. TR's use a 19-20" prop and the TRS can only run about a 15.5" max. Would have thought the seller would have also been identifying it as a TR.

Hello there, I have been very busy a few days with my house that also is a project :-) The boat is a 255 Sedan Bridge from -81 with a 7,4 l Mercruiser. On the original "operation and Mainteance Manual" that was included with the boat says Models 330TR-330TRS. I think I have assumed that the drive is a TR. But maybe it is a TRS ? The prop size is approximately 50 cm or 19,6 Inch on the new one and maybe 1 inch less on the old. I need to turn the outgoing shaft 2 revolutions for the prop to turn one revolution on both = YES ! I guess it´s TR drive I have then. On the new drive the prop rotatets to right and the old one turns to left.
I´m little curious now why the boat will need that big prop ?

// Carla

That's a big heavy boat especially for one engine. Needs the extra blade surface area to move it efficientlly and the lower 2:1 gear ratio drive for the extra power to turn that big prop.