Threadlocker for Upper to Lower attachment bolts

[theydrewa31]

Hello All,

Just a simple question here. Working on an OMC cobra 4.3L. I am currently getting ready to re-attach the lower gear housing to the upper gear housing. The repair manual mentions that the upper to lower gear housing attachment bolts have a yellow/green threadlocking substance that should not be removed. The manual mentions that if the threadlocker has been removed the bolts must be replaced. My bolts don't look like they have much threadlocker left on them. Is there a substitute for the threadlocker that anyone has been able to find? Or should I just re-use these in their current condition and not worry about it? I do plan on using gasket compound on the threads as the repair manual asks for. I'd hate to buy a bunch of expensive bolts over a little bit of threadlocker. I included a photo below so you can see what my attachment bolts currently look like.

Thanks in advance for any help gents!

 

[makomark]

Locktite (liquid) is a reasonable alternative...I'd use the medium (blue) grade unless someone else gives a reason to use a different grade.

 

[theydrewa31]

So blue loctite was my first thought, but in my mind it seemed like it wouldn't work. The manual calls for these bolts to be covered with gasket compound in addition to the threadlocker and I was thinking that the gasket compound would immediately mix with and /or displace the liquid loctite which is very thin. I assumed this was why OMC used a threadlocker that was so thick and sticky so that it would remain stuck to the threads as the gasket compound is applied over top. Of course I could always use the loctite by itself without any gasket compound if you gentlemen think thats the way to go.

Thanks Mako! I appreciate the help!

 

[theydrewa31]

An alternative I had considered was simply using these bolts with the small amount of threadlocker currently between the threads as is and coating the threads with gasket compound then allowing and to sit out for 5 hours or so until the gasket compound thickens. Then I would cover the threads again with more gasket compound just before installing them. I was thinking that the gasket compound would be more a more similar viscosity to the threadlocker that was on there after it thickens up, but then I realized that it probably won't have the strength of true threadlocker.

Let me know if you think this is a better idea?

 

[Edchris177]

Gasket compound is to keep water out of the threads- galvanic corrosion between SS bolts & Al castings.
Buy the blue thread lock in the larger tube, the one that uses a turning knob on the end. Those use a locking compound about the consistency of thin grease vs the very runny stuff in the small squeeze tubes.

 

[theydrewa31]

Thanks Edchris! I ended up picking up some of that stuff. Top and bottom gearcases are now successfully mated together!