Transom 22, good news..1996 502Mag 22.

[Pismo]

So my gimbal is shot, as is the steering pin, seals around it, etc so instead of replacing just the ring and pin i decided to change the entire transom assembly. In addition to a new gimbal ring, pin, etc, this also replaces all my other original items such as gimbal bearing, ujoint and exhaust belows, rams, etc and I can sell the old assem. This would also give me a chance to closely examine the transom for rot. After reading many transom threads I was very fearful that mine was shot or on its way. To my very happy surprise the transom is solid still, very solid. No issues anywhere i could find.


A few things i noticed.
--The transom is exactly 2" thick with 1/2" of glass/gel on the aft edge and then plywood with layers of glass going forward.
--The transom was not a mosaic of dozens or 4 or 5" square pieces of plywood (like I read it would be somewhere) it is solid.
--A nice 3-4" semicircle was cut around the drain plug to help keep water from soaking in there, very nice.
--Everything looked sealed up nicely and solid still.
--There are large 2" holes thru the stringers for water to pass thru.
--The stringers are huge, probably 2" thick.
--Removing the engine took 2hrs and another hour to remove TAssem. 10m to remove drive and engine hatch (which needs to be unscrewed from deck) So 3-4hrs total. Not bad.
-- Lots of wires outside the Merc 9pin standard plug. Mercathode, trim limit, trim sender, others that i dont know what they are, etc.
--Donzi builds a good solid boat.
--Cleaning took the longest.
--Tighten those two top gimbal ring nuts every fall as part of your yearly maintenance. I waited until it was loose and this bought me couple more years but it was still too late.
--If anyone is worried about their y pipe leaking where it hooks to the transom assembly, look elsewhere first, mine was very tight with a gasket and lock washers on all 4 bolts. These were the hardest bolts to remove, very tight.

Let it dry out good over the winter and then paint bilge and re assemble in spring.

Overall a fairly easy job with few surprises. Spring may be tougher getting it back together.

Some photos, starting, hatch/drive, engine out, dirty with TA, dirty TA out, clean, clean.

Cheers

[Mr X]

Great idea, replaces all the worn stuff in one shot...and is much more cost effective.
Nicely done!

[Pismo]

Great idea, replaces all the worn stuff in one shot...and is much more cost effective.
Nicely done!

Cost was certainly a factor but getting a good look at the transom was important.

The 631 magnum TranAssem cost $1900.
Parts to do it the other way were about $1600.
Either way was a lot of labor.

To get PerfMar to do it was $2300+ unknowns.

If I sell the old TA for a few hundred i should be about even and everything is new rather than "fixed" and I was forced to remove motor and get a look at the transom.

[CHACHI]

Will you be replacing the coupler?

Ken

[Morgan's Cloud]

Will you be replacing the coupler?

Ken

I think that's a very good idea. A little extra coin ? Yes , but it'll be done once and for all .

Also , just my humble opinion , don't let anyone talk you into the 'transom seal is all you need' viewpoint.
Put a nice bead of polysulfide based sealant under the new trans plate first to work in conjunction with the seal.

Also easy to disassemble later on if ever needed . 5200 = the other invention of the devil .

[Pismo]

I think that's a very good idea. A little extra coin ? Yes , but it'll be done once and for all .

Also , just my humble opinion , don't let anyone talk you into the 'transom seal is all you need' viewpoint.
Put a nice bead of polysulfide based sealant under the new trans plate first to work in conjunction with the seal.

Also easy to disassemble later on if ever needed . 5200 = the other invention of the devil .

Where would you put it? Just inside or outside of the factory seal gasket?

[Morgan's Cloud]

Where would you put it? Just inside or outside of the factory seal gasket?

I like to do the whole area under the trans plate .No missed spots.
Any excess can be left to cure and then trimmed off neatly like an over sized o ring.
Unless of course you like to wipe and wipe .. either way it's worth it.

I can't remember the 3M product I used , I think it was 1001 sealer but the 'Boatlife' Lifecaulk polysulfide sealant is the same stuff should you end up doing it.

[Tidbart]

Boy, that job looks familiar.
Do as much work as you can with the engine out. It is easy now.

Bob

[Pismo]

Belts, plugs, trim unit solenoids, maybe coupler ($700!) after a good look, just did oil and raw water pump. Any other suggestions? I should remove the VST but up north i never have had any vapor lock trouble. Clean, paint, remount depth sensor more aft. 350 hours fresh water only.

[Pismo]

There was a tan wire taped to the outside of the 9 pin cable that ran up under the throttle body and then out of sight. It did not go thru the 9 pin. I cut it, it was the only one I could not disconnect correctly.

Anyone know what that wire is?

Thanks

[Tidbart]

If you decide to do the coupler, there is a company in Quincy FL called Speed and Custom Marine. He sells couplers made by Lord. They make them for Merc. He has good prices on them, worth a look.

Here is a little write up on the coupler replacement via the Merc bulletin that I did years ago. http://www.donzi.net/forums/showthre...tin&highlight=

I replaced a lot more part than you will ever have to as my boat was used in salt and neglected.

Bob

[Tidbart]

Coupler shouldn't be more than $300, if I remember correctly.

B

[Tidbart]

There was a tan wire taped to the outside of the 9 pin cable that ran up under the throttle body and then out of sight. It did not go thru the 9 pin. I cut it, it was the only one I could not disconnect correctly.

Anyone know what that wire is?

Thanks

That may be the IAT, Intake Air Temperature, sensor wiring. If I remember correctly, the sensor is threaded into the underside of the plenum. It has 2 wires coming out of it, a tan and a black (gnd). That would be an all tan wire with no stripes. The tan wire would go from the sensor to J1 end of the ECM.

If that is not the correct wire, the only other one I see is one that goes from a harness connector for the charging/starting harness to the J2 end of the ECM.

I guess, either way, you have find out where the wires runs.

B

[Tidbart]

Sent you a couple of PMs.

B

[yeller]

There was a tan wire taped to the outside of the 9 pin cable that ran up under the throttle body and then out of sight. It did not go thru the 9 pin. I cut it, it was the only one I could not disconnect correctly.

Anyone know what that wire is?

Thanks

Tidbart is correct on the 2 tan wires. Your water temp gauge also uses a tan wire, but that should be pin #3 on your 9pin plug. If you PM me your email, I will email you the 93~97 Merc 454/502 service manual.