rear bearings

[aaadave]

hi all, i've got a 72 dart slant 6 with 71/4 rear and 9'' brakes. it has no gear whine, but has a bad low growl at all speeds like bad wheel bearings. i have another 72 dart parts car with a good 71/4 that came with a 318, so it had the 10s''. the 10'' drums are missing and cant find any, so i thought about swapping the 9'' drums, backing plates and hardware to the donor rear. now my question. i wanted to try some new wheel bearings on my rear to see if it would fix it and if not, i would swap my axles with the new bearings in the donor rear. every place i checked says the 9''brake wheel bearings wont fit the 10'' brake axle housing. is this right or am i missing something? i thought the only difference in the 72 71/4 rears was the brake size. thanks for the help, dave.

 

[valiantpatrol]

If your quite sure both rears are '72's and both were US built then they should have the same axle bearings. New axle bearings will generally fix the growl you speak of. If you are willing to pull the axle and expose the bearing you can grip the outer shell and move it side to side (toward the wheel mounting face and back towards the driveshaft and not rotate it as if it were rolling) if there is any play at all the bearing is bad. These rears use a sealed ball bearing (with ZERO axial clearance) and not a greased tapered roller bearing. The latter type allows for some axial or side to side play. Its easy for parts guys to get confused when looking these up since Mopar did frequently change the axle OD (bearing ID) and the bearing OD over the years with no rhyme nor reason known to mechanics anyway.

 

[Charrlie_S]

The part stores are correct. The 7 1/4 with 10 brakes is large bolt pattern, and uses a different axle bearing then the 7 1/4 with 9 inch brakes and small bolt pattern.
You cannot swap axles between the two rears.