Allison released a new kit P/N: 29557365 to convert a S9820OFS to a S9823OFS.
This kit is a good collection of minimum parts to convert the transmission to a quality, minimal overhaul standard. The kit is not all inclusive and if a failure is being repaired, there is no way to create a standard kit to be all inclusive. There are simply too many parts variations. Kits will be available to order 08-10-2015, please see Allison SIL 5-TR-14, REV. D posted on our Transmission Page. If you would like more details or pricing, please give us a call at 713-674-9300.