Can't get the lower unit off 1977 850XS

[ssv1761982]

This one has a five inch extension to make it a 20". I can't get to the bolt that holds the torque tab. Am I missing something or do you think it is corroded and I need to force it a little?

[CHICKENHAWK]

Can you 'see' the bolt?

I know it sounds like a ridiculous question, but sometimes there might be crud built up in the access hole.

[ssv1761982]

I can see the bolt but it looks like it is way down there. A 3/8" extension will not fit thru the hole in the five inch extension, the extension has a hole but it is too small. I have a long 1/4" drive extension but the sockets won't fit thru the hole to get to the bolt.

[Scottko]

Are you sure it's a hex head bolt? Maybe an allen wrench head? Or torx head? I'm pretty sure the tab has to come off, as I think there is another bolt under the tab that has to come out to remove the lower.

[CHICKENHAWK]

Maybe there's a special Merc tool for it?

Do you have a Mercury Factory Service Manual?

[W2F a V-King]

If it's the same as my 1975 150 inline 6, ( and I believe it is ) mine has a 15" mid that also has the 5" extension when I bought it.

The bolt that holds the torque tab on is a 5/16 or 8mm allen bolt. You can use an allen key socket with a 3/8" drive.

[phillnjack]

you just need a thin walled socket to get down there, if you dont have one look around for an old steel type box spnner like the old motor bike tool kits etc.
then just weld a bar onto it and hey presto its out .
if the bolt is on there it must have been put in with thin walled socket , or like said above maybe Allen head in the middle of the bolt head ???
need to have another food look down there

[Robby321]

If it's the same as my 1975 150 inline 6, ( and I believe it is ) mine has a 15" mid that also has the 5" extension when I bought it.

The bolt that holds the torque tab on is a 5/16 or 8mm allen bolt. You can use an allen key socket with a 3/8" drive.

Agree 100%...

[ssv1761982]

Thanks guys, afterlooking closer it was an allen head. I had to buy and extra long 3/8" allen wrench. It was almost 7" from the top of the hole to the allen head.

[Mark75H]

Thanks guys, afterlooking closer it was an allen head. I had to buy and extra long 3/8" allen wrench. It was almost 7" from the top of the hole to the allen head.

That's because of the aftermarket long shaft extension. A really sad thing to see on any XS Merc

[phillnjack]

100% on above , who in their right mind done that ? be like scribbling on the mona lisa .

[Robby321]

100% on above , who in their right mind done that ? be like scribbling on the mona lisa .

Yep........and I have long reach 1/4 drive Allen wrenches. Made for stuff like that.

[FUJIMO]

They were made by Bay Manufacturing in Milan, Ohio...for a lot of the Mercury(and Mariner)factory smaller motor extensions originally. Larger Mercury's as well. They are still in business. www.BayMFG.com

[ssv1761982]

One more question. Do I really need to pull the power head to get the drive shaft extension out of the midsection? It is too fat because of the splines to come out the bottom of the mid.

[W2F a V-King]

I don't recall having to do that when I dis-assembled my 150.

Best I remember, that extension came out attached to the drive shaft when I pulled the LU. I just looked at my mid, and there is room for it to come out the bottom or the top.