1974 Mercruiser 255hp Windsor 351 - transmission oil cooler?

[MacShorty]

Happy to say both my engines fired right up dewinterizing them. However, the port engine wasn't pumping water through the exhaust (raw water system). It appears that I am losing water around the lower port side of the engine. Behind the water pick up pump there is a short rubber hose (upper) that connects to a steel cylinder (about 18-20" long) that then connects to another hose that routes into the thermostat housing. I believe that steel cylinder may have a crack in it's housing where it connects near the water pick up pump.

I have not been able to find this steel cylinder in any parts listing. Some old paperwork that came with the boat has a diagram that indicates that cylinder might be a transmission oil cooler. I figured it was some type of heat exchanger so that would make sense. Does that sound correct?

Anyways, since this is the port side engine, there is only a few inches of space before you hit the fuel tank. It appears that if I remove the alternator and the water pick up pump that I MAY be able to reach the two hose clamps at each end and the single mounting bolt in the center of the cylinder.

1) Has anyone ever replaced this part before and have any tips on doing this with the engine still in the boat?
2) Do you know if the fuel tank can be tilted more portward against the angle of the hull to provide more room?

A friend suggested I could possibly use one of those rubber plumbing repair sleeves and clamping it over the crack in the cylinder with some 5200 and it might be good enough to get us by. Do I dare mention JB Weld? lol Considering I have not yet located a direct replacement for this part yet either. NOTE: We do NOT drive the boat ever, we will begin living on it in April, but we DO need to drive the boat 1 mile across the river to our new marina.

1974 Nautaline
Twin Mercruiser 255 Windsor 351 model 32554, serial 3839937
Velvet drives

Thanks for any advice. Pics attached.

Jen

 

[wrench 3]

Check here http://www.iboats.com/Mercruiser-In...4925778--session_id.528467833--view_id.270916
BTW The plug at the lower left in the picture is where you drain the water when you winterize the unit. A rad shop could probably repair and pressure test it, but I don't know how the price would compare.

 

[MacShorty]

Excellent Wrench! I'll double check my tube length before I order. And after seeing that plug, I can easily see how failing to drain that one caused it to rupture this winter. Grrrrr Now I know for next year (this was my first full winter of ownership).

 

[wrench 3]

I believe that the difference between the two applicable coolers is the water hose diameter.

 

[Bt Doctur]

Failing to properly winterize a motor can lead to this

Dont just fix the leak ,remove an end and inspect it internally. Failure to do so could cost you a transmission.

 

[MacShorty]

Yep, I know what happened and why, and now know where to buy one. As I said, this is the first year owning and winterizing this boat and missed the plug. I also said I don't drive the boat and only need to move it 1 mile.

With that said, what I need help with is (as indicated by my questions listed as 1) & 2) in my original post) any advice on how to replace this with the engine still in the boat due to the tight quarters on the port engine against the fuel tank?

Thanks,
Jen

 

[Bt Doctur]

The worst case is to pull the engine to replace it. Another option it to re-route it to a easier location. maybe need new hyd hoses for the trans. could use water hoses from the Mercruiser Blue Water Series FWC motors.might have the correct bends .Check the Volvo motor hoses also.
Think outside the box.

 

[wrench 3]

I can't say that I've ever changed one in that tight of a spot. But I'd try laying across the front of the engines (or is that the back, make that the stern) and reach in with my left hand to undo the water hoses and the mounting clamp. Then attempt to pull the cooler out the flywheel end, removing the oil lines after it's in the open.
Reverse the procedure to install making sure that you get the rotation correct on the oil lines.
BTW In case you haven't figured it out. You have to be a contortionist and ambidextrous to work on boats.

 

[MacShorty]

LOL you got that right Wrench! Wish us luck, we begin the tear down tomorrow. Gonna start with taking off the water circ pump and the alternator to get clearance to the front. And hoping arms are long enough to reach the rear fittings through inside rear panel. Forget moving half the engine components, I had to move half of the bedroom, too. hehe If I am smart, when it gets put back together, I'll include an extension on the drain plug so I'll make sure it gets drained next winter.

 

[wrench 3]

When you pull the drain plugs you need to rod out the holes when the water stops running out, to make sure that the hole hasn't plugged up. So make your extension straight enough so that you can push a wire up into the cooler.

 

[MacShorty]

Update: This job is totally doable with engine still in boat. I also ended up with an exploded impeller that had to be replaced on the water circ pump, but all is well and we are moving boat to it's new home (and ours) this weekend!

 

[wrench 3]

Good news for sure. Enjoy your new home.