Transmission removal - on the water

rocinante33 · #1 (**permalink**) 05-20-2008

I am trying to pull my gearbox with the boat floating. It is a Hurth HWB 50 on a Universal M 25. I unbolted the propshaft, motor mounts, hoses and lifted the engine about 6" (aft end) so the coupling could clear the prop shaft. I used a come-along attached to a beam across the companion way to lift it. I supported the engine on wood blocks & unbolted the bell housing all around its' circumference. So far, I cannot separate and pull the bell housing away from the flange on the rear of the engine. There doesn't seem to be a place where I can get a screwdriver blade or a crowbar in between the two parts to separate them. The components are in pretty good condition with little corrosion that would be a factor.

Does anyone have any idea of what could be binding? Could it be the weight & leverage of the trans on the pilot shaft preventing if from sliding off of the splines? Are there any tricks I can use in the process, with the limited space I have to work? Should I lift the tail of the trans with a scissors jack, then try to pull it aft?

Thanks, in advance, for any advice you can give.

P.S. I plan to replace the tran$$$ with a ZF10M, one size up and I hope more robust. The boat is an Ericson 33 (Ron Holland).

Maine Sail · #2 (**permalink**) 05-20-2008

You might need to try this technique which includes pulling the engine all the way out....

Rockter · #3 (**permalink**) 05-20-2008

Roc...

If the gap between the surfaces needs to be oil-tight, do not, do not, do not lever them apart with a screwdriver!!!
It will leak afterwards.
Try a mallet, then (judiciously), a hammer.

Maine Sail · #4 (**permalink**) 05-20-2008

Quote:

Originally Posted by Rockter

Roc...

If the gap between the surfaces needs to be oil-tight, do not, do not, do not lever them apart with a screwdriver!!!
It will leak afterwards.
Try a mallet, then (judiciously), a hammer.

Actually, that's incorrect. Where the bell housing mates up to the engine it is NOT oil tight.

The bell housing actually has a weep hole at bottom dead center to allow any leaking of the transmission input seal or the engines rear main seal to drip out of the bell housing indicating a problem. This is the area on an automobile where the clutch is, on a standard transmission, and as such you DO NOT want any leaking oil from a rear main seal getting on clutch plates so they design them with a weep hole.

That being said, a screw driver will only tend to throw the housing off center and the splines of the tranny and engine will bind and it won't go anywhere. It needs to be pulled straight off the engine! Use a wooden or rubber dead blow mallet and tap around the transmission output flange evenly. This will break the rust bond around the perimeter then slide it straight off.

What ever you do be VERY, VERY careful using penetrating oils in this area! PB Blaster, and the others, will EAT a rear main engine seal or a tranny seal in about 10 minutes flat and it will permanently be destroyed!!

rocinante33 · #5 (**permalink**) 05-20-2008

Right. I will be careful with the PB Blaster. On you first post (2nd post in this thread), Maine Sail, did you mean to attach a link or a picture? If so, it isn't working for me.

I know if I can't get it out with your other advice, I will have to pull the engine all the way out.

Maine Sail · #6 (**permalink**) 05-21-2008

It was just a picture of Tim R.'s (from the Ericson site) Ericson 35-3 when he pulled the transmission to replace it. Check the Ericson forums for more info.

Ericson Information Exchange

P.S. Many, many Catalina's from the 30 to the 36 use the M-25 and the same transmission yet the Ericson's seem to burn through transmissions at a higher rate? I don't know why though. I've owned three boats with that transmission and never had any problems, however, I do change my fluid yearly...

rocinante33 · #7 (**permalink**) 05-21-2008

Thanks. I have seen Tim. R's work on the Ericson site & studied it before I tackled this job. I can't imagine why these trannys could last longer in Catalinas than Ericsons......unless Ericsons get used more? That is doubtful, and there are SO MANY Catalinas out there!

Rockter · #8 (**permalink**) 05-21-2008

Well, I did say IF it needs to be oil-tight.
Don't lever the final drive off my olde Volvo like that.
Gearbox maybe, but don't lever the final drive off it like that.

rocinante33 · #9 (**permalink**) 05-25-2008

Problem solved, thanks to the sharp eyes of the admiral! I had removed all 9 bolts from the rear around the circumference of the bellhousing. She spotted an additional bolt which came in from the front (inboard of the circumference), through the engine flange and threaded into the bellhousing. When we got that bolt out, the bellhousing came out very easily. Now I can order a new tranny and dampener plate and, I hope, get back sailing sometime soon!
Thanks all, for words of wisdom.