Transmission rebuilders in midwest

[dphatch]

Looking for some recommendations  on  manual transmission rebuilders in the Midwest. 2007 997 C4S exhibiting unwillingness to engage reverse gear. Recent clutch replacement. All forward gears engage fully and no issues downshifting while driving, only issue is when engaging reverse, the  synchro will not fully engage. Cables have been checked and are not the issue. All gears can be engaged manually at tranny and with shifter when car is stationary, engine running and off. With transmission removed from car no symptoms on a mechanical problem were apparent. Tranny oil replacement with Mobilube PTX is next step but if that doesn't remediate the problem only other solution is tranny teardown and rebuild. 

[Silver_TT]

Gbox out of Boulder, CO gonna be your best bet.  Hopefully the OEM Mobilube PTX was the only oil ever put in the gearbox since using other non-OEM oils can cause damage.  Call Stan at Gbox and tell him the problem and he will be able to tell you how to proceed.  No one in the US knows more about these gearboxes than he does.