3/4" shaft will not fit into 3/4 bearing

[daveingeb]

What am I doing wrong? I" have this new 3/4 jackshaft and new 3/4 bearing and the shaft will not fit in the bearing hole!! This is a project to got to an all-chain drive and get rid of the comet torque converter. just too much trouble with dirt and belts and all. So I am sitting here with this shaft and ready to install it and bearing 6203-RSNR will not accept the 3/4 shaft. Its all going in a murray..

 

[ML-TOYS]

Does the shaft have rust on it ? Did you measure both ? Did you try a little oil?

 

[Russ2251]

Measure both with your caliper.
If you do not have a caliper, I strongly suggest you get one...especially if doing (DIY) your own work.
Will pay for itself the first time you use it.

 

[mckutzy]

Is there a burr or a dented end,(check the keyway) those often prevent bearings to slide on.

 

[itsathepete]

NTN shows the 6203 series as 17mm bore (.6693") which is too small for 3/4" shaft (.750") there is no metric equivalent of 3/4" you need to make sure you are getting the right size. What are the numbers on the bearing and manufacturer

 

[Russ2251]

NTN shows the 6203 series as 17mm bore (.6693") which is too small for 3/4" shaft...

Good catch.

 

[chancer]

Would a 19mm (.7480) bearing work? Yes I know why not jut get a 3/4" bearing

 

[mckutzy]

I think you need 3/4" pillow blocks for the bearings. Not standard shaft bearings.
Most of the time, those type of machine bearings are shrunk fit on shafts for motors ect.

 

[OzFab]

Would a 19mm (.7480) bearing work? Yes I know why not jut get a 3/4" bearing

3/4" = 19.05mm... so... no...

 

[daveingeb]

Yep, you guys are right on! So that was a 17mm bearing and jackshaft-- I mistook it for a 3/4". I just assumed that murray would use a US dimension jackshaft. My project involves removing the comet torque converter and going to a pure chain drive. This frame has springs so i had to use the integral jack shaft mounts (a funny tube behind the seat) stay tuned.