Split Case Question, Three bond

[Guest]

Team,
If you haven't seen my new member question, I am now neck deep trying to restore this 1980 GS1000G. I have the engine out and the case split, I'm currently repairing the failed oil seals between the engine and the secondary gearbox. I've never split a case before and looking for advice on how to apply three bond sealer. Do I apply the sealer anywhere where metal will touch metal? See attached with "Red Lines"

Thanks, looking for advice from anyone that has done this before
JA

 

[Nessism]

Correct. Cover those surfaces entirely, even around the bolt holes. I've had engine case leaks where oil got into the bolt passage and then leak down under the bike. And be careful when tightening the screws. A torque wrench is good to use, set to the low end of the spec, but use feel too and stop tightening if you feel like the threads are on the verge of letting go. This is a common problem with 40 year old engine cases.

 

[Guest]

Correct. Cover those surfaces entirely, even around the bolt holes. I've had engine case leaks where oil got into the bolt passage and then leak down under the bike. And be careful when tightening the screws. A torque wrench is good to use, set to the low end of the spec, but use feel too and stop tightening if you feel like the threads are on the verge of letting go. This is a common problem with 40 year old engine cases.

Thank you Nessism!,
So be generous with the Three bond and apply them everywhere as you stated above. Yes, I have to torque spec, but I believe the manual says to tighten the top first in ascending bolt order. That's a problem because I have the engine upside down. Also what happens if some of the three bond gets onto the "oil seals" where they may meet or touch, should I be concerned?

 

[KiwiAlfa156]

"Generous" may not be the right word. The gap the sealant is filling is thousandths of a inch. If excessive sealer is applied most will squeeze out from the joint. If the excess falls off there is a small risk it could block an oil passage. I say small because the chunks are usually to big to pass the mesh strainer on the oil pump pick up
Very thin but complete coverage might be a better description.

Too much sealer

Sealer chunks in the oil pan

I'm about to button up the cases of my 750, and will be going through the same process. One key thing is to make sure the mating surfaces are clean and grease/oil free prior to apply the sealant. I'm going to wipe all the surfaces with oil and grease remover before the sealer goes on.

 

[Nessism]

Lower crankcase screws first, then the uppers. The most critical are the 8 screws which hold the crank. Pretty sure those are first.

 

[Guest]

"Generous" may not be the right word. The gap the sealant is filling is thousandths of a inch. If excessive sealer is applied most will squeeze out from the joint. If the excess falls off there is a small risk it could block an oil passage. I say small because the chunks are usually to big to pass the mesh strainer on the oil pump pick up
Very thin but complete coverage might be a better description.

I'm about to button up the cases of my 750, and will be going through the same process. One key thing is to make sure the mating surfaces are clean and grease/oil free prior to apply the sealant. I'm going to wipe all the surfaces with oil and grease remover before the sealer goes on.

Kiwi,
Thank you for the pictures, that helps give me an idea on how much is too much! Secondly, I am having some issues removing the oil seal residue from the secondary gear box case. Actually for a 40 year old bike it is several places where the oil seals are sticking. I ordered some plastic razor blades to help scrap those off. Any other ideas on how to remove old gaskets and seals?

Thank you

 

[KiwiAlfa156]

Kiwi,
Thank you for the pictures, that helps give me an idea on how much is too much! Secondly, I am having some issues removing the oil seal residue from the secondary gear box case. Actually for a 40 year old bike it is several places where the oil seals are sticking. I ordered some plastic razor blades to help scrap those off. Any other ideas on how to remove old gaskets and seals?

Thank you

Hey Jason, Can you post a pic of the problem? Is it an oil seal, a gasket or old sealant?

 

[craz1]

You may want to check out Locktite 518 for bonding those cases. I have done the last 8 bikes and the results are great. Don't have to worry about the product setting up or skimming over as it cures once the cases are together due to lack of oxygen. I also have been using it on my cover gaskets.

 

[Guest]

Hey Jason, Can you post a pic of the problem? Is it an oil seal, a gasket or an old sealant?

Here is the picture of the lower case as I am cleaning it up and getting ready for three bond. All of these spots feel smooth, but I have been scrapping with a plastic razor and using a drill with an attached 3M plastic bristle. The upper lower case is pretty clean, but the lower lower here is where Suzuki applied the bond as it is visible in the pics.

• How clean does this need to be? I just want to make sure three bond adheres.
• Secondly, what can I clean this entire piece with before three bond to remove oil and debris?

 

[KiwiAlfa156]

Hi Jason, It looks good. If the razor blade isn't snagging and its more of a stain than a lump or layer, you should be good. The crankcase itself is vented so the pressure inside it isn't enough to blow out the sealant, its just there to keep the oil in. Acetone, or painters wax and grease remover wiped on with a soft cloth and air-dried (which is immediate) is a good step to ensure the sealer bonds to top and bottom surfaces.

This is my upper case and I'm happy with it. I'll give it a final once-over. The wax and grease remover -which is still a to do- may even shift the stains.

 

[Guest]

Guys, I am doing a dry run by placing the lower half of the case back onto the block/crank. After reading a few threads I thought I would make sure the shifting of the gears works now that I replaced the oil seals within the dog cam. The engine is presently in the upside-down position. The GS1000 was in neutral when I removed the engine. After a few wiggles, the forks slid into position and the case closed properly..

Everything was going great when the gearshift shaft decided to pop out of the teeth pawl holder. No Biggy right? But I don't know where it was positioned when it popped or what gear the bike was in.

• Does the bike need to be in neutral for reassembly?
• How do I make sure my shifter forks are all aligned and gears will work before I apply threebond?
• What are the major concerns here or am I freaking out over nothing?
• For reference, I never touched the shifter forks or the shifting cam
• Any tips or tricks?

I was planning on applying the three bond later tonight, but I'm concerned about the shifting of the gears before I close the case up.
Thank you in advance

 

[chuck hahn]

one side has 5 teeth and the other has 4. The THIRD TOOTH on the one with 5 teeth goes in between the 2nd and third of the 4 tooth side. follow me??? so tthere will be 2 teeth on each side of the third tooth on the 5 tooth side. hold one hand up with 4 fingers and the other with all 5and interlock your fingers to simulate the pawls teeth. Youll get a visual i hope

 

[chuck hahn]

line them up and post a pic and ill see if your good

 

[Guest]

line them up and post a pic and ill see if your good

Thank you! yes I read that alignment in the clymer manual. See attached pic of where it is now. I just wanted to make sure that if I reassemble this motor that the gearbox works and all 5 gear positions.

• If you are telling me it doesn't matter which gear you are in it only matters that the teeth line up and the forks are positioned within the gears... then I believe I am good.

 

[chuck hahn]

The third tooth on the shifting drum should have the same teeth on each side of it. If your even then your good. If your off a tooth you can index the shifter lever later. Just put the bie on the center stand and put the clutch cover on withot a gasket and work the shifter while wiggling the rear wheel. If it goes good then put the gasket on and call it a day. If it hangs up move it 1 tooth and try it all again.

 

[1980GS1000E]

I used red grease to seal the cases on my CB1100F and it works wonders.

 

[Nessism]

I used red grease to seal the cases on my CB1100F and it works wonders.

Did Honda build the engine that way, or are you going off script?

 

[Rich82GS750TZ]

grease... as a gasket? really?

 

[Guest]

Guys,
The threebothree bond worked great, I found the best way to apply is with an artist brush. Squeeze on the case, then smooth out with the brush, but leave it light. Not too much as the cases will compress.
Thanks for all the help!

 

[1980GS1000E]

Did Honda build the engine that way, or are you going off script?

Do you know something that I don't? Very interesting that you said that. I rebuilt the engine and found red grease had been used. It made splitting the cases quite easy and it wasn't leaking so I used it when I put everything together. I have no idea if they had been split prior to my getting the bike, but do you know if Honda did this?