Crank Noise?

[ChrisGooch]

I noticed that my crank was making a "clacking" noise when I rotated it manually (with pistons off, etc...) I pulled it and the crank seal (flywheel side) is shredded/melted and the bearing seems to be missing a large number of balls. This is the first time that I've pulled one, so im not sure if this is normal or not for the bearing. Should I replace this or just pack it with grease? I've ordered a new seal for it

 

[john zigler]

minimum you need a new bearing. ( you do not pack with grease. that is only wheel bearings).

i would strongly recomend getting a good shop to inspect the rest of the crank.

good luck. zig

 

[ChrisGooch]

John,

I compared this crank to a friends. The bearing is competely different. The crank is an SBT, I dont know if that should make any difference... I do know that the seal that was destroyed is not the same as teh OEM seal, as it fits into the bearing and seals it up.
There is no debris or damage in/to the crankcase, nor was there any in with the flywheel, i dont know where the balls could have dissapeared to?

Is it possible that this is just how the bearings are on sbt cranks

 

[john zigler]

John,

I compared this crank to a friends. The bearing is competely different. The crank is an SBT, I dont know if that should make any difference... I do know that the seal that was destroyed is not the same as teh OEM seal, as it fits into the bearing and seals it up.
There is no debris or damage in/to the crankcase, nor was there any in with the flywheel, i dont know where the balls could have dissapeared to?

Is it possible that this is just how the bearings are on sbt cranks

no, that bearing is junk!! it is missing the cage that holds the balls apart. your engine may have just spit pieces out the exhaust.

if it were mine, or you came to me as a customer, i would recomend a new crank, or get it rebiult, by a reputable crank shop.

just my .02

zig

 

[Mike W]

I agree. You need a new or rebuilt crank.

 

[WFO Speedracer]

New crank no doubt about it.

 

[SUPERTUNE]

I won't rebuild a SBT rebuilt crank, they weld them up too much and that makes them hard to get perfectly trued after the rebuild the 2nd time. Just buy a new Hot Rod crank new in the box and use only new OEM Yamaha crankshaft seals. (never use the junk aftermarket seals)

 

[ChrisGooch]

Thanks everyone, I'll pick up a new crank as was suggested

 

[dbrutherford]

Chuckie, what about OEM Kawie seals? I know the WSM, Jetlyne, Hot Products, ect.. for Kawies are much cheaper. Maybe I answered my own question. lol

 

[DAG]

the question is where the the ball's end up?

 

[superramjet]

quality bearing there. The last sbt crank we pulled was missing a thrust washer by the rods, where do those pieces go? where they ever installed?

 

[Flash-FX]

the question is where the the ball's end up?

Every crank I destroyed ended up with the balls looking like in the picture above. The bearing cages break up in pieces then go through the motor. Sometimes it happens slow..sometimes quick. The tell tale head and piston dome beat up with all the pieces until the rings stick and bore get scored. $$$ uch:
I remember finding a pieces of cage rattling around in my water box. The front bearing is the one that seems to go first from the extra stress supporting the flywheel.
Did you catch it in time before the cylinder carnage?

 

[RSaggiorato]

The cylinder and pistons got taken out by the cage breaking. We ended up rebuilding the top end of the engine. However the walls did not look as scored as I thought they would, the pistons and rings took all the damage (Both being SBT).
Happy to say he got rid of all the SBT stuff, replaced all seals and everything is working nice thanks to Chuck .

Rob.S.

 

[D-Roc]

what flywheel where you running? I had the same thing happen a little while ago, my rad flywheel was way outta balance and it would ruin the seal and front bearing, i swapped cranks and then hydrolocked that one so i got a new oem bearing and seals and put the stock flywheel back on, so far so good.