Can transmission problems affect Dyno #'s?
 

Could messed up bearings, synchros, etc. affect the Dyno #'s you're putting to the ground?



How about a bad MAF?

Yes, although unless it is really badly screwed up drivetrain parts wearing out should be minor differences. A bad MAF would make a large difference though.

Transmission could majorly affect dyno output...



If your clutch is slipping, only partial power is getting to the wheels..



Any problems resulting in the transmission not 'transmitting' the maximum amount of power from the crank to the wheels will result in a different dyno result.



If for whatever reason, your transmission problems are causing problems with revving until redline or can't use 4th/5th gear, etc. it will definitely be a major impact.



MAF issues can cause a HUGE difference in the dyno numbers if the fuel/air is being screwed up by the MAF.