mysticteal2kz28

Hello, I am rebuilding my T56 and when I removed the 5/6 gear from the main shaft, i noticed that the main shaft surface was not smooth like the rest of the shaft. The surface has some brownish/redish layer to it which i removed with scotch brite. The metal as seen in the pics below is rough to the touch, as this is the main shaft i don't know if i should run it like this or if this is a sign of wear that warrants a replacement. Any thoughts?
Thanks again for all your help!

85MikeTPI

iTrader: (9)

Normal. Did the 5/6 cluster come off easy or did you need a puller?

calhoon

iTrader: (6)

This is called fretting. It is not a problem if the 5/6 spool gear still has a press when installed.

mysticteal2kz28

The 5/6 gear just slid out by hand. Thanks for the info, I thought i had to get a new main shaft.

85MikeTPI

iTrader: (9)

If the gear slid off, most likely you will need a new mainshaft and cluster. TDP offers a welding service for this if you're tight on funds.

mysticteal2kz28

Is the reason that you believe i would need to replace the main shaft is because there needs to be interference between the 5/6 gear and main shaft? What could i do to confirm the main shaft needs to be replaced? Also you mention cluster is that 5/6 gear?

Jeremy@RPMTransmissions

iTrader: (12)

Yes the 5th/6th gear needs to have an interference fit onto the mainshaft. If the gear was removed by hand without any tools then the interference fit is gone and the mainshaft and gear both need to be replaced.