Removing Gearbox Outer Cover -Stuck Gasket

Greetings:
New to this forum. I live in the Washington, DC metro area. I recently picked up a mostly rebuilt from scratch 1973 Commando 850 MKII. Among the 1st orders of business was to replace what appears to be a leaking kickstarter seal. The easiest option is to try popping in a Timkin seal per all the truly wonderful advice on this forum.

Now then... having removed the oil, the kick starter, the shifter, all the outer gear box case bolts, and disconnected the clutch cable... the darned case cover is not coming off, likely due to the gasket seal. Things seem in good shape but I have no real place to grip on so that I can give it a good yank. I tried a little heat here and there with mapp gas torch and still nothing.

So here I stand; stalled. Any suggestions and tricks to remove the outer case and the gasket without scratching the cover or casings by using big tools, blades etc?

Thanks all
-->FJ (SvenSven)

PS Next on list is addressing the dang ubber tight clutch. Cable is new, so I was going to look into the cable routing and then clutch plates; possibly add the extra plate on the outside as per the great advice on this forum. 1 step at a time!

SvenSven said:

Greetings:
New to this forum. I live in the Washington, DC metro area. I recently picked up a mostly rebuilt from scratch 1973 Commando 850 MKII. Among the 1st orders of business was to replace what appears to be a leaking kickstarter seal. The easiest option is to try popping in a Timkin seal per all the truly wonderful advice on this forum.

Now then... having removed the oil, the kick starter, the shifter, all the outer gear box case bolts, and disconnected the clutch cable... the darned case cover is not coming off, likely due to the gasket seal. Things seem in good shape but I have no real place to grip on so that I can give it a good yank. I tried a little heat here and there with mapp gas torch and still nothing.

So here I stand; stalled. Any suggestions and tricks to remove the outer case and the gasket without scratching the cover or casings by using big tools, blades etc?

Thanks all
-->FJ (SvenSven)

PS Next on list is addressing the dang ubber tight clutch. Cable is new, so I was going to look into the cable routing and then clutch plates; possibly add the extra plate on the outside as per the great advice on this forum. 1 step at a time!

Click to expand...

You can tap or pry against the portion of the casting where the clutch cable connects. My experience is the gasket sealer glues this cover on pretty well.
Stiff clutch is due to how the cable is routed. No sharp turns and the most direct is best. Mine goes around the sweating goose neck down the right side of the main frame tube, over the top of the air box then straight down to the gearbox. Works very well.

Alrighty now your talking my real area an any expertise, STUCK FAST stuff. Get the lock into handle type heavy duty razor blades and tap them into the seam, then don't be so timid with the flame and use a hook tool in holes to bump cover out after tap tap tap or pry pry pry on as many razor blades as can put in the seam. Might also try a pre soak in brake fluid or DMSO or acetone to try to soften the glue with some heat cycles before the brutal part starts. Also may be best to pull tranny and service on bench. Chisels and screw drivers tend to score the sealing surfaces, till already broke a gap free some. Also note just focusing the group mind on your seam seems to work magic I found next time around.

The main trouble with the KS seal is the groove is too deep for good o-ring compression on shaft so fill that in some or get thicker o-ring, or try proper oil seal which usually means machining for it.

Tap as stated above (I would use a rubber mallet) ... and remove the small round inspection cover. Then pull on the cover with your fingers hooked thru the hole, while tapping with a mallet. My 2 cents ...

Prolly some hard gasket sealer from years ago. Obviously we don't want to mar the case/cover, or damage it. BUT, sometimes a mark will happen. If you have an assistant, he can PULL on the cover with a hooked tool inserted throught the fill plug (an old type "L" shaped tire iron) while you work the part line with a wedge... I've had great success (daily on industrial housings) with a small (3/8" wide) cold chisel tapped right into the gasket. The minor marring can be dressed with a file, done on the underside, it'll never show. As SOON as it opens a bit, insert small screwdrivers, working around.

I'll second hobot's razor knife blades, but don't get cheap thin ones. Plenty of heat. Once the seal starts to break it should not be bad, just try not to use screwdriver or chisels. Yeah, hook inside the inspection port and pull.

Clutch could be anything, one thing at a time is best. You may find it's just the adjustment too. If the stack height is right, you should be able to adjust it so you feel the diaphragm break over it's hard point like a compound bow. Then it's easy to hold, but pulling pressure depends on stack height, cable routing. You can get Teflon cables too.

Dave
69S

Hi
Having double checked you have all the screws out! use a large screw driver or tyre lever through the inspection cover and find a point for the tip/point of the screwdriver, then use the leverage to add some pressure while tapping the case with a hide or plastic mallet.
JohnT

Besides the seam glue there is friction of shafts to break free too and if for some reason they are tweaked out of square to the cover could bind for more turmoil to over come. A Command can really make or break our sense of mechanic manhood ugh.

Well, I had same problem on gearboxes. i abhor the steel razor blade on aluminum, hate to take a chance of cutting into soft aluminum . So here is a suggestion, I did it, it is a PIA, but it can work and won't screw up the nice aluminum pieces. Find around the house, or go buy something you really need in a thick, gnarly blister pack. You know the kind like you get a memory stick in from Best Buy, or or a fully edge sealed one that tools sometimes come in and sometimes have the little RFID security doodad inside. The kind that when you try to open it in the car because you cant wait to get home, and you don't have a pocket knife and you try to pull it open and it is tough as nails and you get all sweaty and mad and think "Why do they use these #$@&^ blister packs if I ever find the guy that invented these I will choke the living daylights out of him."

Take the blister pack and get scissors and cut out a rectangle of the stuff (or 2 or 3) that are large enough to hold comfortably (don't worry it won't be comfortable for very long no matter how you cut it up.) Hold the piece with a corner sticking out and use the tip of that corner to saw into the mating line between the two parts. Go back and forth, over and over. Throw the plastic part down and say "That Walker is an idiot this will never work." Get a coke, or a beer and stare at the gearbox some more, and have a cold drink and cool down. Now cut out a piece of that blister pack that is what you really want since you now have a better idea what to do and go to town on that gearbox. Break through on a small section and feel happiness. Stop for another beverage. Critical here: resist the urge to jam a razor blade or (shudder) a screwdriver in the open edge (screwdriver = REALLY bad idea DO NOT DO THIS). You will notice the edge of the plastic piece you are using will now be sharpened a bit. May need to make a new plastic piece. When you get enough of the seam open you can take the cover off by hand, or, more likely, you will need to take a few of the plastic pieces and fold them over to make a strong plastic piece to pry with. Feel great satisfaction that it is apart and you have not marred the aluminum in any way. I have a bunch of bits of plastic that I save for this kind of stuff around aluminum (plastic putty knives tend to be polyethylene and too soft as they need to bend in use - you need tough, stiff plastic bits.)

Much easier to do this if the part is out of the bike.

When you get around to thinking, I should polish this thing up, scotchbrite does a good job, but be careful, there are about 45,672 grades of scotchbrite and some will scratch the holy crap out of the aluminum surface. I got some from zoro tools, I am sure you can get it cheaper elsewhere, meh.
http://www.zorotools.com/g/Scouring%20P ... /00052312/
The difference is the white, I think, is just a nylon pad, other colors have abrasives in them and some are VERY aggressive and will leave scratches that are very hard to get out as they are too deep and require a lot of removal of material. Show polish on aluminum doesn't last long in my opinion, too easy to get minor scratches that show easily, so a good bit of elbow grease and stepping down from a mildly abrasive scotchbrite to the nylon pad will buff your part out to look like a nice balance of matte - shiny finish, ie. if you use it like a mirror you can see your face is there, maybe can't see well enough to tell it is you, but a nice shiny surface.

Just some thoughts, that is what I like to do.

Thank you very much... with all these great ideas I too was able to get the gearbox external cover removed. Check!

Now then - Next - How does one actually remove the bushing that is holding the rubber washer/o-ring in place against the gearbox external cover/housing? I presume I need to remove the bushing, and remove the rubber washer/o-ring and THEN replace it with the Timkin seal and a spot of adhesive and then reverse the process by pressuring the bushing back in - right?

How can one do all this without scratching the bushing, housings, gearbox covers et al?
And I thank you in advance.. again.
-->FJ

SvenSven said:

How can one do all this without scratching the bushing, housings, gearbox covers et al?

Click to expand...

Finesse, not savagery. :mrgreen:

If it is an oring in there, you just pick it out. If you are replacing with a seal then simply heat it up around the parimeter till the bushing drops out. It doesn't take much.

A heat gun will do. Map gas is also great but is really hot.

Just a word about the seal mod, a friend did it to his, leaks way worse than the o-ring did. I don't know the condition of adjacent parts, but just a thought.

I recently also tried the timkin seal and it leaked worse than ever. Went back a put a new o ring in an all is well

Huh. I had Phil (Fair Spares) put in my seal and it's been fine since. He did the shift lever too. It was less than $100 back then delivered. But I thought someone found an auto seal that works in the original slot?

Dave
69S

I have some drop in x-ring seals that work a treat. I've had them in my Combat for over a year and not a drop out of them.

PM if you're interested in a set. I have several sets left. Also clutch and alternator beleville washers and a replacment clutch retaining clip.

Well.....life is interesting. Turns out it already had a Timkin in there. Previous owner had zero data on bike when he bought it rebuilt years ago and I just bought it.
So, I guess I need to have it milled and rebuilt professionally. The dang Timkin metal backing part is still in there due to a ton of red Locktite and will not come out. That was also what was holding the bushing in. I tried MAPP Gas a tad but backed off since I will be sending out.

Soon as I learn how to post pictures I will send photos. What do you all think? The outside was not pretty either. I don't want to over spend but hoping a professional can remove Timkin then mill and mod with new seal and buff and polish etc.
Anyone have guesstimates and advice other than CNW ...?

-->FJ

hobot said:

Get the lock into handle type heavy duty razor blades and tap them into the seam...

Click to expand...

I have to say I don't agree with this method. Razor blades can easily damage the sealing surface. Anything between the seam is not a good thing to do.

I buy steel rod at the hardware store slightly smaller diameter than the bolt holes and cut two pieces about 6" long. Stick them in the holes on either end top side first so you can use the rods to pry on the case. Drill bits will work in a pinch. All you need is a little force with this method and they usually break lose.

I would try heating the hell outta that locktite and try a regular o ring in there. Worked for me

I shipped mine off to Phil at FairSparesAmerica today for a $55 retrofit and installation of 2 "modern" o-rings in the kick starter and the gear shift holes.
As part of the upgrade service he will remove the Tikmin o-ring metal backing that is stuck in there by the RedLocktite. Given the new borehole is slightly larger, some of the nicks and dings around the kick starter hole on the case cover will now also get removed. When I receive it, I will polish it to get a new fresh look and re-assemble on my own.

I'll report back to see how this works out in the next 1-2 weeks.
Cheers all.
-->FJ