Crank seals

[kevinfries]

What is your opinion on replacing the crank bearings and seals. And where can i get the crankcase seperator tool. Do you think it is possible for someone to replace the seals and bearings without having a dealership do it?

[cr2504life]

I think it is possible, I think all you need is the case puller and a clutch puller. And possibly an impact gun to remove the clutch nut and main gear bolt. I have a manual and it helps alot.

[kevinfries]

any other comments? Where can i get the case seperator?

[Blitz393]

i did it all by my lonesome with my daddy for help (ok so thats not all by my lonesome... anyway : )

we had basic garage tools: sockets, allen wrenches (we used Allen head sockets) screwdrivers (impact screwdriver that you hit with a hammer HELPS A TON)

we also had a Flywheel/harmonic balancer puller and that helped press the cases apart. we used our 12-ton press from out back to press the other bearings out and in, and an impact wrench for the clutch basket nut. pretty basic tools, minus the impact. you CAN do it without the impact but plan on having at the very least 2 people: 1 to hold the basket, and one with a huge 3-foot breaker bar on your socket wrench

it's do-able. we did it in 3 hours

Rob

[ossagp]

a flywheel puller costs about 15 dollars,,,the harmonic balancer puller or about any gear puller can be made to separate the cases,,,,

[ossagp]

Oh,,i prefer to warm the cases and tap the bearings out rather than press them. Just a preference I have, so the press that Blitz has is not necessary for the job.

[FFRacing11x]

Now that we have the case splitting issue ironed out...let's address the case assembly procedure...anyone?

[ossagp]

Didnt we already do that?

[ossagp]

Warm the cases, cool the bearings and drop them (the bearings) in all the way. I like having the transmission assembled into the clutch side of the cases. (yep I have had some left hand clutch bikes). Once the bearings are in I measure the depth from the mating surface of the case to the inner wall adjacent to the bearing on both cases and add the two dimensions. Sometimes it is necessary to measure it at the bearing, but the two are usually pretty close. Now I measure across the crank. Compare the width of the crank to the case depths. Split the difference and use something to make an assembly shim so that the crank is close to center when you reassemble it. (I use business cards most of the time.) Now I heat the center of the main bearings. My favorite way is to us a Rockwell QR brake pin and heat it in the over or with a heat gun, propane torch etc. I usually use two, keeping one hot all the time. For anyone who wants a cheap heat slug the part number I use is a Haldex/Midland C66866 or Rockwell 1259-n-274. They cost about 2 dollars. After you have the slug heated to 350 or so degrees, you just set the slug on the center of each main bearing for 2-3 mins and you can get the crank to go in pretty easily.

On cases like Yamahas that have no gasket, I like Yamabond sealer. Spread it with carboard etc . Take your pick on 2 or 3. On Hondas I usually just grease the gasket to keep it in place if the surfaces are good. If they are not so good, I use Gasket Cinch. If they are really bad I use the Yamabond, but for the most part you can cure a bad mating surface with 600 grit taped to plate glass. (Just rub it until the nicks are gone.) I used to go down to a jewelry store in my hometown and do that at night on these really thick windows that they had. Of course it you have a lapping table available use it, as glass isnt always as flat as it seems. (But lots of us have used it just as described.) Keep in mind that there is a limit to how far you should lap or "backwoods" mill any case. For the most part though transmission shafts have .020" plus of end play and your crankshaft generally has as much to spare.

Anyway,,once I have the crank in, I like to check the rod to see if it is centered,,,drop the cylinder on and measure. Tapping either end with a mallet to center them is acceptable by some of the best tuners I have met. (some of the worst too.) I mention comparing the rod in the cylinder since not all cases have the split in the center. Some even split horizontally. My point it that it is really imortant to me for the rod to be as close to the center of the bore as I can get it.

The seals go in last for me. (seems like the original question involved them) I have them flush with the outer wall of the seal socket. If for some reason I am trying to avoid a wear groove in something really old and hard to replace, I shim the seal to run on a new surface or push it in slightly further. (You are kind of on your own like I am, in those cases.)


Remember to torque anything on the end of any of the shafts to the factory specs. Keep the manual handy too.

When I wakeup I will remember something else.

[CR250oldtimer]

Originally posted by ossagp


When I wakeup I will remember something else.

HAHAHAHA.... I love it!

[cr2504life]

Its funny because it is so true.