Seized lower unit bolts

[wmk0002]

I have a lower unit off of a longshaft 1982 9.9 hp Evinrude which has seized bolts connecting the LU to the longshaft extension. I have mistakenly sheared a couple off but it happened with surprisingly little effort. I got another one out cleanly too but quit before I made the job more difficult. I may be able to get the remaining ones out with some penetrant and heat but no matter what I am going to have to drill out these couple of sheared ones. The issue it that the anti-ventilation plate leaves little to no room for a drill. Any ideas for this? I could probably sacrifice the extension piece in other to drill in from the backside if necessary...I think they are pretty cheap used, plus the whole water pump assembly will likely need to be replaced. It has very weak pee stream plus it appeared to be a kicker motor used in salt so I bet the cooling system was probably neglected.

 

[Shaugh]

Dealing with seized bolts is part of the game especially for a salt water motor. Soak for a day and either remove em or break em... once you get it apart the repair work is pretty straight forward. There's no magic right answer for bolts that are really locked up.... especially when they're low quality steel ....

 

[Pappy]

Try your penetrating oil if you like. As far as heat goes you will probably need oxy/acetylene to get enough heat.
If you do not have that then my advice would be to cut the heads off the bolts, pull the L/U and try heat again on the threaded areas. Many times the bolts are stuck by corrosion in the shoulder area below the head and above the threads. At any rate by doing this you stand a decent chance of removing the damaged fasteners rather than drilling each one.

 

[bobberboy]

You can try an impact screwdriver too but go easy on aluminum. It worked on a 60's 40hp Johnson for me. Available at parts and home improvement stores, Harbor Freight etc.

 

[ADIBOO]

Try using the 50/50 acetone and auto transmission fluid as a break free. I'd do that for a couple days before trying to break them loose and let it soak in.

Sent from my SAMSUNG-SM-G891A using Tapatalk

 

[kofkorn]

If you have a small welder, you can weld a 1/4-20 nut onto the stud that is sticking out. Usually, if you weld the nut and then immediately try to unscrew it, the heat from the weld is enough to allow you to break it free. The key is to get good penetration on the stud, and get it cherry red. If it doesn't work, and you twist the nut off again, you can always drill it.

I've had a lot of success getting bolts out of aluminum this way. About 80-90% of them come out.

Good luck!

 

[wmk0002]

Thanks for the advice guys. I'm going to drain the LU oil and get it upside down and put some penetrant on all the fasteners and let it soak for about a week. I'll try everyone's advice going forward and post back with any more specific questions.

 

[LDUBS]

You can try an impact screwdriver too but go easy on aluminum. It worked on a 60's 40hp Johnson for me. Available at parts and home improvement stores, Harbor Freight etc.

I inherited one of these from my father about 20 years ago, though not the same brand. It has proved to be real useful to have around on many occasions.

 

[Mark_Fisher]

Dealing with seized bolts is part of the game especially for a salt water motor. Soak for a day and either remove em or break em... once you get it apart the repair work is pretty straight forward. There's no magic right answer for bolts that are really locked up.... especially when they're low quality steel ....

+1 for "the name of the game." Even good stainless isn't that strong. Soaking, tapping, heating, and finally drilling out are all part of the mix. A local reputable outboard shop has a flat "no work on motors over 10 years old" rule. It leaves ME out, but I see why they implemented it.

 

[DaleH]

When re-inserting the bolts, coat them with a non-drying gasket sealing compound. That's what the OMC factory service manuals recommend and my brothers and I have been doing that on dozens of motors used annually in service in salt waters for 30 to 40-years now and we've never had a bolt stick.

1st thing I do on any new-to-me motor is to remove the bolts (one at a time) that I expect to have to service - clean them - apply the proper goop (some will use the Triple Guard grease) - and then re-torque them to the proper torque spec.

Actually this is probably the 2nd thing I do ... the 1st is to get it running reliably !

 

[muddywaders]

x2 what pappy said.It will be easier to weld a nut on when its apart or sometimes vice-grips will work.Dale what product is non-drying gasket sealer?Is it the same as form-a-gasket?I was told to use grease when re-installing bolts into aluminum.Im sure loc-tite makes a product but gasket sealer is probably cheaper.Wish the factories would use some type of corrossion inhibiter.

 

[DaleH]

Dale what product is non-drying gasket sealer?

I use the OMC or Bombardier gasket sealing compound. Maybe non-drying isn't the right word, it sets up and protects, but will somewhat 'peel or strip off' when you take the bolt out. So maybe it forms a waxy like coating. One of my brothers tried grease one year and went back to the OMC stuff.

I am sure PermaTex makes an equivalent product ... in fact I'd bet $$ they make it for OMC and other OB makers.

 

[DaleH]

Just read this on-line ...

"OMC Gasket Sealer is the same as Merc's Perfect Seal. In the automotive trade it is known as Perfect Seal #4. Loktite 30517 is exactly the same as OMC Gasket Sealer. Note that Permatex Ultra Black is an equivalent to OMC Gasket Sealing Compound."

Maybe Pappy can chime in ...

 

[Pappy]

Dale has it covered. The GSC works well and has for decades.
In South Florida, the center of salt water woes, the savvy mechanics are now and have been using Tef-Gel as the primary lubricant on any submerged hardware. They have reported great success with this product for long term submersion. Long term submersion is the fun term for an owner that neglects proper service intervals.
https://www.amazon.com/s/?ie=UTF8&keywords=tef+gel&tag=googhydr-20&index=aps&hvadid=107976870885&hvpos=1t1&hvexid=&hvnetw=g&hvrand=17107623164698170108&hvpone=&hvptwo=&hvqmt=e&hvdev=c&ref=pd_sl_8g3xwrzfs3_e_p13