stroking Posted October 15, 2011 Report Share Posted October 15, 2011 (edited) humm...isn't this suppose to be the best crank bearing to use ??? well this one has about 3hours max run time on it........ cranks still good to go....its a 10mil forged crank anyone know what would cause this....faulty bearing maybe ??? Edited October 15, 2011 by stroking Quote Link to comment Share on other sites More sharing options...
Strm Trpr Posted October 15, 2011 Report Share Posted October 15, 2011 I just read about this exact thing potentially happening if you run helical gears and TZ Bearings. Quote Link to comment Share on other sites More sharing options...
Strm Trpr Posted October 15, 2011 Report Share Posted October 15, 2011 Right here, post #6. http://bansheehq.com/forums/index.php?showtopic=147827&st=0&p=1275716&hl="bearing"&fromsearch=1entry1275716 Quote Link to comment Share on other sites More sharing options...
Ron Strecker Posted October 15, 2011 Report Share Posted October 15, 2011 (edited) What brand is the TZ bearing stroking? Using TZ bearings causes the crank to float side to side inside Banshee cases. Using the helical gear adds lots of stress on the crank. When Yamaha built the TZ racing motors in the 70's. Yamaha had the center bearings clipped in the case to keep the crank from moving. Yamaha also used straight cut primary gears on all race motors. I don't use TZ bearings. I use 11 & 13 ball maxload bearings on all my stroker cranks. Since I'm a 1/4 mile drag racers. For extra insurance I do have my cases grooved to clip center crank bearings. Look at the picture. Shows where to add the clip groove in the case. My machine shop does the work. Edited October 15, 2011 by Ron Strecker Quote Link to comment Share on other sites More sharing options...
Coupelx Posted October 15, 2011 Report Share Posted October 15, 2011 What brand is the TZ bearing stroking? Using TZ bearings causes the crank to float side to side inside Banshee cases. Using the helical gear adds lots of stress on the crank. When Yamaha built the TZ racing motors in the 70's. Yamaha had the center bearings clipped in the case to keep the crank from moving. Yamaha also used straight cut primary gears on all race motors. I don't use TZ bearings. I use 11 & 13 ball maxload bearings on all my stroker cranks. Since I'm a 1/4 mile drag racers. For extra insurance I do have my cases grooved to clip center crank bearings. Look at the picture. Shows where to add the clip groove in the case. My machine shop does the work. you have a part number for the 13ball maxloads? Quote Link to comment Share on other sites More sharing options...
Ron Strecker Posted October 15, 2011 Report Share Posted October 15, 2011 you have a part number for the 13ball maxloads? 13 ball bearing is only used on Crank Works billet cranks. 11 ball bearing will fit on Banshee cranks & LH driven shaft (countershaft output). Two Stroke Shop sells those $43.50 Quote Link to comment Share on other sites More sharing options...
Coupelx Posted October 15, 2011 Report Share Posted October 15, 2011 13 ball bearing is only used on Crank Works billet cranks. 11 ball bearing will fit on Banshee cranks & LH driven shaft (countershaft output). Two Stroke Shop sells those $43.50 good to know. i can get the 11ball maxloads locally but didnt know about the 13ball ones. Quote Link to comment Share on other sites More sharing options...
locogato11283 Posted October 16, 2011 Report Share Posted October 16, 2011 You're running a 10mm motor with stock drive gears. That's your problem, not the bearing. Stock drive gears want to pull the crank out of thaw case anyway. When you go adding all that HP you need straight cuts. Quote Link to comment Share on other sites More sharing options...
lms1977 Posted October 16, 2011 Report Share Posted October 16, 2011 A guy I ride with saw two of the bearings go one was his motor with 3 months on it with straight cuts on it. Quote Link to comment Share on other sites More sharing options...
BigRed350x Posted October 17, 2011 Report Share Posted October 17, 2011 humm...isn't this suppose to be the best crank bearing to use ??? well this one has about 3hours max run time on it........ cranks still good to go....its a 10mil forged crank anyone know what would cause this....faulty bearing maybe ??? The helical cut gear with the TZ bearing is your problem. If you had chosen the correct bearing for your primary gear application, you wouldn't have this problem. With a needle style bearing like the TZ bearing you need to run straight-cut gears. If you can't afford the straight-cut gears, go to max-load bearings on your crank. Quote Link to comment Share on other sites More sharing options...
BigRed350x Posted October 17, 2011 Report Share Posted October 17, 2011 Right here, post #6. http://bansheehq.com/forums/index.php?showtopic=147827&st=0&p=1275716&hl="bearing"&fromsearch=1entry1275716 Bingo! Quote Link to comment Share on other sites More sharing options...
pabansheematt Posted October 17, 2011 Report Share Posted October 17, 2011 humm...isn't this suppose to be the best crank bearing to use ??? well this one has about 3hours max run time on it........ cranks still good to go....its a 10mil forged crank anyone know what would cause this....faulty bearing maybe ??? Haha, join the club. I had the same thing happen to me last week. It had about 10 hrs on it. I'll never buy another one. Quote Link to comment Share on other sites More sharing options...
pabansheematt Posted October 17, 2011 Report Share Posted October 17, 2011 You're running a 10mm motor with stock drive gears. That's your problem, not the bearing. Stock drive gears want to pull the crank out of thaw case anyway. When you go adding all that HP you need straight cuts. I have straight gears on mine and it blew the bearing? wtf? Quote Link to comment Share on other sites More sharing options...
locogato11283 Posted October 17, 2011 Report Share Posted October 17, 2011 I have straight gears on mine and it blew the bearing? wtf? Maybe the bearings are junk too. Who knows? I do know that the stock gears will amplify the problem. Quote Link to comment Share on other sites More sharing options...
BigRed350x Posted October 18, 2011 Report Share Posted October 18, 2011 I have straight gears on mine and it blew the bearing? wtf? Did you torq your cases up with some clearance tape on the bearing outer race and check its squished width to ensure the bearing had the proper clearances to the cases? If the bearing has any movement inside the case it will eat the bearings as well. Think about the forces being applied to the bearing when the cylinders fire. It wouldn't take much movement of the bearing race inside the cases to start getting some vibrations. Did you check that your crank was running true before the install? Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.