As posted elsewhere I have a severe hard part failure in the OD section of my trans. Sounds like grinding gears or a shell hitting something in OD.

I want to eliminate other causes of this transmission failure so I don't hurt it after the rebuild. Like an electrical failure... Oil sample sent out to check for coolant.

Transfer case shifted to neural:

Stepping on the throttle to maintain 2000 RPM I get a RPM drop by 500-1000 RPM as the transmission shifts. I have to add throttle to bring the RPM back up. :wtf1: Is the RPM drop normal? This is a DB2 mechanical pump - RPM steady in Park at 2K. Noise still there in OD...

Add prior code 68.
Current codes of 85 and 86.

DTC 68 is transmission component slippage. Of course you gathered that.

DTC 85 Undefined Ratio Error.
Circuit Description for DTC 85: This is the same for DTC 85.The computer calculates ratio based on the input speed and output speed sensor readings. The computer then compares the known transmission ratio to the calculated ratio, for the particular gear range selected.
DTC 85 will set when unknown gear ratio is detected for any gear but 4th.

DTC 86 Low Ratio Error.

Circuit Description for DTC 86: The computer calculates ratio based on the input speed and output speed sensor readings. The computer then compares the known transmission ratio to the calculated ratio, for the particular gear range selected.

This DTC will set when transmission commanded gear is in 1 or 2 and transmission is
mechanically in 3rd or 4th gear.

A faulty transmission manifold pressure switch can set these codes.

Faulty Transmission input speed sensor can trigger ratio error codes. However I would check wiring to the input speed sensor. Take out the input speed sensor and clean thoroughly. Replace and test. Place transmission in gear with the input speed sensor disconnected. Transfer in neutral. Use multimeter set to AC. Test both leads while the engine is running. Have a bud rev the engine. Not accurate but enough to tell you thumbs up or down.
Damage to the torque converter could have resulted. Have it looked at.

Shop can’t say if the over drive sprag failed first or the bearing failed first. But the drum and planetary gears in the OD are also trashed. No case damage thankfully.