Splitting 850 Cases

[Guest]

Hopefully I placed this thread in the right sub-forum.

I'm splitting the crankcase on my 1981 GS850GLX. The motor's out of the frame. The head, cylinder block, pistons, clutch, oil pan and so forth are removed. The bolts on the top and bottom have been removed. I checked several times to make sure that I didn't miss any. The bike's at the point where it's upside down and the cases are "tapped" with a dead blow to break the seal. Yah, that's not going to work on this bike. Before I get frustrated and do something that I'll regret with the cases, I figured it would be a better to ask for help/ideas on splitting these buggers. The cases have never been apart...still sealed from the factory. I searched for threads on splitting cases but only found one and it wasn't an 850.

[loud et]

The service manual covers complete teardown and rebuild if I'm not mistaken....so that's the place to look to assure you haven't missed any bolts (like in the oil pan area) or whatnot. Although it sounds like you are at the point where you have a really bare block and shouldnot have missed much.
Also like they use on the stator cover and clutch cover there are small circular alignment pins or rings I should call them in the bolt holes. These may be making it hard to get a split started on the case....thats if they use them on the cases.
Other than that it must be that 35 year old case sealant holding it tough. Others who are experienced it splitting cases will chime in. In the meantime I would go over the manual which can be found at bike cliff's page.

[loud et]

http://members.dslextreme.com/users/bikecliff/

If you don't have this. It's gold.

[BadMonk]

Yep, I already had the manuals needed for the project.

Like I said, everything's removed - to the best of my knowledge - that's supposed to be removed. The two crankcase halves won't even start to separate with a dead blow hammer and 'tapping' or 'lightly' hammering... like it says in the books. I definitely don't want to harm the cases by doing something dumb so I was wondering if anyone here has a tip or trick on splitting cases, besides gently tapping with a hammer. Thanks!

[tkent02]

Do this 850 case have the place for you to put in a bolt and force the cases apart? Some do, some don't. But first make sure you have the right number of empty bolt holes.

Don't know about the 850s, but on tne the 450s, 550s and 750s there are a few hidden bolts.

[BadMonk]

The 850 doesn't have hidden bolts, unless those are the 3 inside the oil pan. But the oil pan came out before even looking at any case bolts. The rest of the bolts are in plain sight AFAIK.

Do this 850 case have the place for you to put in a bolt and force the cases apart?
Hhmm...I don't know if it does or not but it sounds like it should since the 450s, 550s and 750s have it. What would it look like cuz it would more than likely be real helpful? Like two tabs (one from each case) over top of each other with space in between? I'm just guessing at this point...can you tell?

[BadMonk]

A thin putty knife will slip between the cases at the front of the motor, not at the back or sides which is where it's entirely stuck together.

[loud et]

There are a few under the starter....and it says to remove the oil pump......
Sorry, trying to brainstorm here.

[BadMonk]

Done and done. Thanks.

Brainstorming here too...I used my Clymers in the garage because it's old, beat up, dirty. The Service Manual given to me by the PO is in the original plastic bag and is in 'like new' condition. So, I didn't want to use that in the garage...it's really cool to just have on a shelf at this point. Anyhow, I compared the Manual against the Clymers about ten minutes ago. The procedures are different, esp when it comes to disassembling the rear of the motor...which is where this thing is hung up. So...it's been a long day... tomorrow morning I'll check my work against the Suzi Manual. I have a sneaking suspicion that's going to be the root of my problem. Okay, maybe just wishful thinking.

Thanks for all the responses. I'll let you know what I find tomorrow (Wednesday). Hopefully the Manual provides the resolution.

[Grimly]

Fer gawd's sake resist the temptation to use a sledgehammer.

[bwringer]

Getting the old, rusty dowel pins to move can be challenging. Make sure you know where these are and concentrate efforts around them.

Alas, there's no place on the 850 to install a bolt and force the halves apart. Probably for the best.

IIRC (it's been a while) there are a few places you can CAREFULLY pry.

[BadMonk]

Today, I compared Clymers to the Service Manual step-by-step. All I can say is...Clymers is the pits. Following Clymers will never ever get anyone to the Promised Land. It's that bad on this particular subject. This weekend I'll get to work again using the Service Manual. Will write more as things progress with the Manual.

[alke46]

Today, I compared Clymers to the Service Manual step-by-step. All I can say is...Clymers is the pits. Following Clymers will never ever get anyone to the Promised Land. It's that bad on this particular subject. This weekend I'll get to work again using the Service Manual. Will write more as things progress with the Manual.

That's been widely publicized here for quite some time.

[poppadre]

I'm having the same problem with my case too (GS750). When I reassembled it I used three bond in anticipation I would never have to crack the case again. I should have known things never go as planned. Spent all of last night with lacquer thinner and a paint brush painting the seam of the mating surfaces. It worked well softening the three bond that was pushed out making removal easy. But I don't think it's getting in the seam as the case still won't budge. I currently have the engine sitting about an once off the bench on stilts on three points where the top case overhangs the bottom. I'm going to take a torch to one side of the seam tonight and hope that does the trick while gravity helps with the bottom half

sorry to steal the thread with this question. But are those bungs on the case half meant to be used to separate the case. I was thinking of getting some nuts and bolts that fit in there to press the bottom half off. Using a smaller washer to prevent the bolt driving into the case. I'm just a bit worried about snapping cracking or bending the case. Has anyone else tried that method with success?

[poppadre]

Hey BadMonk. Today I picked up some 5/16 nuts and bolts to try to press the cases apart. Out them in and I noticed right away it with little effort this case started to split at the front a few millimetres but kept matted for most of the length of the case. This made me certain that I was missing something. Took another look around the case and voila. There was a missed bolt holding the two together this boot was a 6mm about 3 inches long that sat right behind the clutch basket between the oil seals. Very easy to miss. And I'm pretty sure it wasn't mentioned in the manual (I'll double check that tomorrow). But just because you think you got every bolt or you got every bolt meantioned in the manual you may still have missed one like I did. I never took my 850 engine apart so I couldn't say if it has the same bolt but I hope it you solve it and get hat case cracked open. I had a huge wave of relief once I did! Happy wrenching