Thread shift shaft seal.

[malrv1]

Hi Does anyone know the what the thread is on a lower shift shaft seal housing? Mine was very corroded and I had to destroy it to get it out. I would like to be able to clean up the thread before in the case before putting in a new seal.

 

[GA_Boater]

What version of Mercruiser?

 

[malrv1]

MC-1 But I think they are common to most models?

 

[harringtondav]

Our local Ace Hardware store has a sizing panel with every inch and metric stud and tapped hole. Take your new part to a hardware store and size it up on one of these panels, or fish through the nuts until you find a match. Then buy your tap.

 

[achris]

The very best bet in most cases, and in particular yours, is to just buy a complete new bushing with the new seal already installed. It's highly likely that the current bushing is not going to seal around the outer edge of the new seal anyway. Whenever I have to replace a shift shaft seal, it get a new bushing... The old one goes straight in the bin (or the box of replaced parts that are returned to the owner)...

To clean up the threads in the housing, you're going to need a thread file, not a tap. A tap that size will be VERY expensive.

Chris......

 

[malrv1]

Thanks Chis

I have ordered the new bushing with seal and a new shaft. It wasn't very pretty once I got it out. They haven't arrived yet, The housing has survived OK. Just need to clean up the thread. I am guessing being US built it will be a UNF thread. About 15/16" I reckon. I understand about the thread file.