The diagram below is for those of you who get a tranny without all the relays etc. that are in the vehicle. If you already have one, you may consider rewiring it for split shifting. NO engine braking whatsoever unless the overdrive is engaged. If you downshift the O/D while going downhill, you will lose all engine braking, and you will gain speed getting it shifted back into O/D!! I usually lock it out on gravel roads so I can have engine braking also. This is a diagram for wiring a split shift control setup for your T-85N transmission. This can be used for one you’ve bought outright and have no original circuits for, or modifying the one you already have. This is Borg Warner’s original wiring diagram scanned from a 1965 Chilton’s manual. If you have an all original truck with the overdrive, this diagram should be usable. The DPDT relay in my circuit substitutes for the special kickdown switch that mounts above the gas pedal in the old
vehicles.

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