The Dukes transmission [without motor, brake, and release arm] can be overhauled at Dukes, Inc for approximately $3,200 which is the latest quote I have from them; I no longer keep a Dukes overhaul on the shelf for exchange. However I do have exchange Dukes units available [not Dukes, Inc OH]. See the parts for sale page. If you choose the Dukes Inc repair, your transmission will be returned overhauled but they [Dukes] do not consider cosmetic improvement of the tube and release lever a part of their service, because they supplied the transmission to Piper without that component. I have the tube and release lever done separately; you may likewise.
Dukes, Inc says that they have never released a repair or maintenance manual for these transmissions. They continue to say, therefore how can anyone else claim a repair on an 8130 referencing what manual? So if this is accurate information, then the only approved repair facility for the Dukes transmissions is Dukes, Inc. I could be wrong on this opinion.
And if you aren’t bored enough just yet, there is a note in the Single Comanche Parts Catalog concerning the Dukes transmissions. It seems there was a bad run of actuator screw from serial number 919 through 1068 [see SL-650 above]. If you have one in that serial range you must replace it immediately.
If your Dura transmission has a loose bearing, you are probably out of luck. I usually have a Dura on the shelf for exchange. I am not aware of any facility holding an approved process to repair this problem except the facility in Michigan who charges about $3,300; some may be on the horizon. Again if your Dura has a bearing retention problem you had best find a Dukes to replace it before the supply dries up. The Dukes transmissions were demanding $2,250 in used condition, no motor. From there you’ll have to do an inspection and if the gears are bad, add another $3,200 to get it repaired at Dukes.
More recently these transmissions [without release arm and motor] are fetching nearer to $3,000 on the tail of the statement that Dukes quoted me $8,000 for new PMA transmissions.