Marinette Boat Forum

Good day all!
For the past couple of seasons our port side tranny has had s small leak at what I believe is the rear seal. The boat has sat 10-11 months of the year the past 4 years while we are in Ohio. It leaks more the first couple of days we are cruising and then the leak slows. I am speculating that the seals get moistened and the leak slows. They need replaced though! The boat travels and is currently in jacksonville Fla on the hard awaiting our next leg of our journey this coming spring/summer.
We are going down to the boat next week to spend a week replacing the aft deck and while at it replacing hardware and wheels on sliding doors and screen doors. I am think while the aft floor is out is the best time to do this job because we will have a little better access/room to work. I am intimated by this job and really don't know what I am doing I have spoken with the staff mechanic, Rick, at Green Cove Springs where the boat is about giving me an estimate for completing the job. I am also thinking if we are doing the one, we should likely go ahead and do both trannys.
Does anyone have thoughts/experience on this job who has done it? Any idea on how many hours of labor I might expect? Any specific other things that we should definitely do at the same time?
Thanks in advance for the input!

Good questions but I can't give you the answer you need. Others can. However, a couple of thoughts: first, it makes sense to replace both if it's financially feasible, otherwise don't fix what ain't broke. Second, leaks don't get better, they only get worse so repairing the leaker is important and your timin g -- while the deck is out maks it easier for the mechanic to get better access.
By the way, when you speak of "next leg of our journey" what are you referring to???

With your aft deck off now's the time to fix it. Once the prop shaft and the tranny flange are out of the way the seal should be relatively easy to replace. Worst case use two small bottle jacks and 2x4 blocks at back of the engine to take the load off the two tranny mounts and pull the whole tranny. I did it this way when a cooler let go and flooded the tranny with sea water.

I changed one of mine, and it was no small job. The big nut that holds the flange to the output shaft is hard to remove. An air impact wrench is needed. I made a beam to go across the two window sills and used a hoist to lift the rear of the engine. Then removed the transmission and mounts. Replaced the seal, replaced the transmission, and aligned the engine to the shaft.
If the other one is good, leave it alone. You could try to replace the seal with the transmission in place but don't be surprised if you have to pull the transmission.

Eric, make up a small gantry out of 4 x 4 wood or 2" iron pipe. loosen the rear trans mounts,disconnect the coupling, with a chain come a long to lift the motor. Lift it about 3 or 4 inches and put a 2x4 under the oil pan. Then pull the trans out- to work on it - doing it in place is not good for a first attempt. It will slide back in place, then lift it out with the gantry.Watch your cooler lines, I leave them attached and pull the entire assembly, easier and no leaks. You will need to cut down an 11/16" box end wrench to get the lower transmount bolt out , unless you pull the mounts all together. If you go that way - get realigned, in the water. Busia , is correct that nut is tight on the trans flange. My advice would be let the yard mech or a close tranny shop install your seal if you are uncomfortable.It is easy or inexpensive to have done. Call them in advance to set up and you will get it back in half a day. Then reverse order to put it all back, fill with fluid and check operation. Sorry not good on pics - I'll put one on fb of it pulled apart.

Thanks for the input and instruction guys!

I spoke with the yard mechanic at Green Cove Springs where the boat is and he was on the boat looking at it. He has done the tranny removal and putting back in many times and stated the exact steps that have been discussed here (that parts reassuring). He says there used to be a shop that would do the rebuild in Jacksonville but no longer. Says the nearest shop he knows of is down in Tampa area. He’s going to do some calling and research and call me back.
It seems this would be something most any transmission shop could/would do?? Any recommendation in the Jacksonville area?
Also, where would I order the rebuild kit?

Do you want to change the seal or rebuild the transmission? If you only need the seal, it's about $20- $30 on eBay. Then a half-hour labor to install it. A rebuild kit and labor will be expensive. I would also compare the price for a rebuilt transmission from a shop and give them yours for a core. Just tell them which way it rotates. A shop can be cheaper than parts and labor to fix yours.

So....
Back again requesting advice. I had the yard mechanic pull our starboard tranny and it was sent to a shop for estimates on replacing seals and/or a complete rebuild. Ouch!! Seems to be an expensive proposition either way. They are estimating $1360 for just doing the seals (8 hrs of labor was very surprising to me) or $2400+ for a complete rebuild. Do these coats seem inordinate or in line for having a shop do this work?

Attached are the two estimates for
1) complete rebuild
2) new seals only