2000 Mercury 90 Lower Unit Stuck

[goldenchop]

I am trying to remove the lower unit on a 2000 Merc 90 and it is stuck. I have the Clymer manual and have followed all instructions - removed prop, removed trim tab, removed 4 nuts attaching unit plus additional nut near trim tab. have tried wd 40, used rubber mallet, jumped on unit - it won't budge. Any suggestions?

 

[greasemonkeyozi]

Re: 2000 Mercury 90 Lower Unit Stuck

Hopefully another mechanic will back me up on this, but I have been studying my manual covering mercs and I believe somewhere that if a lower unit does get stuck like that, the prop shaft has to be cut. Let me find my manual and reconferm this, I havnt had this problem befor.<br /> Hold off on this post and let another mechanic give you more advise. There may be something in the way you havnt done yet.

 

[corm]

Re: 2000 Mercury 90 Lower Unit Stuck

did you take out the bolt or nut under the trim tab?

 

[The Marine Doctor]

Re: 2000 Mercury 90 Lower Unit Stuck

If it was not the dreaded 5 Bolt...sometimes the dowl pins stick...really tight. If you are sure that you have all the bolts out...it should come. Sometimes you need to use a Deadblow on it.<br /><br />TMD

 

[goldenchop]

Re: 2000 Mercury 90 Lower Unit Stuck

Yes, I removed the nut that is located near the trim tab. On this model, there is no nut directly under the trim tab (I removed the trim tab and checked). So now, I have all 5 visible nuts removed.<br /><br />What is a deadblow?

 

[goldenchop]

Re: 2000 Mercury 90 Lower Unit Stuck

OK, I had to enlist the help of a local mercury marine mechanic to remove the LU. He ended up using a torch along with pry bars and finally worked it loose. The issue was some corrosion on the two studs (one in front, one in back) that was holding the unit in place. Removing the 5 nuts would normally allow you to easily remove the LU. <br /><br />He also pointed out that the anodes were crusted over with chalky power - a good sign that they are not doing their job and that corrosion was likely. Recommended removing the LU every year for normal maintenance and lubricating appropriately.<br /><br />Thanks for all the help - you were right!

 

[The Marine Doctor]

Re: 2000 Mercury 90 Lower Unit Stuck

For future reference...a DeadBlow is a rubber hammer or non marring or marking object to beat on something with.<br /><br />TMD