Weird crankseal crankshaft problem By drahken (Read 470 times)

[drahken]

ok.  i had this crankshaft, i had to replace it.  had an extra parts bike, crankshaft was good.  i checked the rod.  biek had probably 3000 miles on it, piston ring broke.  i checked the rod play in the crankshaft.  it was good. 
my old crankshaft, needed replaced.

so i done a rebuild, and put the oil seals in.  then it wouldnt stay going.

let me throw this in.  when i was getting ready to rebuild, there was little spots of rust on the crankshaft on some parts.  so i thought id dip the crankshaft arm into vinegar.   after about 4 hours i thought that might not be good on a crankshaft iron.

so i looked it up and someone said its, not so good.  so i went out and got the crankshaft out.  i gave it a baking soda bath and then sprayed wd40 on it. 

it looked duller.  then i read up on the internet, how to shine cast iron.  a brillo pad and wd40 to make it shine.  didnt know what would happen with the crank dull, if it would seal on the crank shaft oil seal, if it would rust.. maybe.  So, i did it.  ddint take a lot, and it was shiny. a little darker.

anyway so i couldnt keep my bike going so i done a leak down test.  i found out the crankshaft oil seal, was blowing air out around the crank arm. on the vairator side.  all the air i pumped in came out around it and it was blowing the water i was srpaying on it, off.

i used stock seals for my scooter.  its a 2 stroke honda.  i took my old cranks seal and slide it over the arm and it was just sliding past it pretty much on the, sealing section of the crankshaft.  on the variator side of it.  the seal was barely sliding on the crankshaft  ..'s arm.  when i moved it up and down it. the seal was supposed to be measured, 19.4mm inside,

i looked up the cranks size supsoed to be, and it's 20mm.  my old crank i pulled out, that i had to replace, i measureed it and it measures, 19.97mm about the smallest.  i measured the one in the bike, and it measured, abotu 19.4mm. 

i measured decided, to check the rest of the cranks measurements to see if i used the brillo pad and messed it up to see, if it would have, other problems.    the part where teh variator sits is supposed to be ..14mm. i measured my old crank and the one in my bike, now.  and the old is 13.98 maybe at the smallest.  and the one in my bike, new, is 13.97 maybe at the smallest.

both cranks, got around 3000 miles on them.

i have no idea.  did i screw up the crank dipping it in vinegar, and using a brillo pad? ?  im not sure a lot about what to do about the crank, but i looked it up online and found a seal with almost the same dimensions,  my stock one is 19.4 x 31 x 7 mm.  so i found one that measures 19 x 31 x 8.  its a little wider. 

but what went on here with this crank?  i think it looked like the crank on the bike, was leaking aroundd that spot cause the seal, looked loose. 
when i looked at the variator seal when I took it off and, as I was looking around, for a leak taht was just blowing the air out as i pumped it in, the seal looked crooked or melted or soemthing.thought maybe it was  where i installed my motor by heating.  but the cranks cold.  i dont know.

but after i got the calipers out i found out.  what do you guys think?  is going to happen?  this bike wasnt running for a reason.  the exhaust, wasnt really off. it was broke at the exhaust mount bolts. and bent and broke off, the top end. 

did i do the damage? or will the bike have mroe prolbems later down the road?  or should since i already know my old cranks in good measurements, vinegar and brillo pad and wd40 it?  shoudl the brillo and wd40 done that much damage?  i didnt scrape, real hard.

[jct842]

the rust has probably pitted the surface of the crank. vinegar will not eat up cast iron, but it will eat rust. Sounds like you may want to start over with a good crank.

[drahken]

it wasnt pitted, it was barely, a little bit of rust.

and, also I could slide, and I did,  the crankcase oil seal back maybe a little bit. it wouldnt hurt it. but as i slid the seal back, which I did, it still just leaked air, past the crankshaft like blowing it out, and blowing the water off as i tried to pressurize the case.

do you really think i scratched away that much, metal with a .. brillo pad and wd40?  i didnt, shine it, for like more than a little bit.  i done it shined it up.  went another day and tried to make i think the whole crank a little shinier. then right before i installed it, i shined it to make it smooth. or smoothly.  more smooth than it was. it barely had a nick on it, ijust wanted to be able to not have air leak aroudn it, but it wasnt dinged up or nothing.  \

[Bashan]

You're arguing with yourself son, you're trying to convince yourself you didn't mess anything up. Well there's a good chance you did. Take it from a guy that's been down the "I farged up" path more than once, get new parts and start over. It hurts the wallet but it's so much easier on the psyche. Rich

[drahken]

what.

i said if i pushed teh seal back the bike still wouldnt hold any air in it? it just blew around the shaft, which measured, front to back, 19.4mm wide.

it wasnt abig spot of rust

[Alleyoop]

One of two things the crankshaft has scratchs on it or the seal is the wrong size no two ways about it bro.
Alleyoop

[drahken]

i pushed the seal back and it leaked in the middle.

IN THE MIDDLE OF THE CENTER OF THE OIL SEAL.

[drahken]

are you telling me ive sanded, with some brillo pad and a little bit of wd40, cause this is exactly what i asked, down .5mm off of a crankshaft arm? like i said i only scrubbed it up, like 3 times real quick. first time probably more but just rubbed it. i wasnt trying to even bother to remove the rust, just shining it. I was SHINING it. ? how could i of rubbed off .5mm of arm on it?

thats the only question im askign you guys i dont really get it are you saying it would?? seal?

or are you sayig its scratched from one end to the other and its leaking out of one little spot on the seal lip? like one spot oh a length of a knife blade thich. or soemthing. are you saying that that's on my scooter?

[Alleyoop]

Ok, here is a seal I labeled it (1) and (2) where it is leaking 1 or 2?

[Alleyoop]

Take a picture of your seal on he crank. You had to take the seal out and many WILL scratch the crap out of the crank because of the way and what they use to take it out.

[drahken]

well the seal is kind of not very good shape now. and i didnt get a picture of it. just i know on , its leaking on 1, its leaking on the inner part of the crankcase seal. where it seals on the crank shaft arm. it would puff out air whatever i pumped in, it. and water would spew away from it. i used some calipers, and got them on it, and measured 19.4mm.. tahts what i got. the seal is a 19.4mm seal on the inside. the crank is supposed to measure 20mm. and theres no air seal.

anyone ever used another seal before? on a crankshaft or something that wouldt seal?


I have no idea why it, wont seal. why the cranks smaller, the other part of the arm i dipped, in vinegar, and brillo pad scrubbed it, twice to shine it up was all. the 3rd time i shined the crank i only done on the oil seal lip section. the arm is supposed to measure 14mm, on down it, where the variator goes on, and the arm, does measure 13.97 or something.

dont have no idea why its messed up like that. thats all ive done. has anyone ever used another oil seal, on something that the shaft isnt up to the same width before? and i dont know what took it out. i still, have another fresh crank, its not usuable but the measurements all are good though. ive measured it, and everything. it matches on the variator part the honda crankshaft, same 13.98 - 13.97mm. measured. the oil seal lip section though, the old one 19.88 and the new one, is showing 19.41 or something everywhere i check.

do you think itll be alright to use another crankcase seal with different measurement? think i should check the rest of the crank, that got stuck in vinegar. the rest of it, i havent went over, its ran fine. just the leak, and i think pretty much it was coming from there.

[Alleyoop]

Well if the seal is pretty messed up already like you say, you need a new seal. How did you put the seal on and what did you use?

[cyborg]

You may want to see if you can get a seal with a smaller Inside diameter, with the same outside diameter,, and if the crank seal area isn't all scratched or scared Up or ridged it shouldn't leak

[drahken]

it was a brand new seal and stuff. i just couldnt get it. when it blew air all around it, i thought, maybe the seal melted, or teh crankshaft, is worn there? i didnt know. had no idea, didnt think that itd be this. i measured the seal, and it seemed about right on, like it was fine. the crankshaft arm is what i was like, this wouldnt seal? then, i checked the other crankshaft i just pulled that didnt leak there. tehn.
i found some 19x31x8 seals.  i was going to try them