MDC Drive Sync was put on my boat before I bought it. 39 Top Gun with NXT drives. Had the drives pulled over the winter to check them out and grease all fittings and such. Took the boat out for the first time over Memorial Day weekend. Noticed that my drives were not syncing. Getting a red flashing light on the unit when drives were all the way down. Called MDC today(Tuesday) and talked with Mike. Had to re-calibrate the unit. I did so by pulling the cover off. You will see a reset button on the mother board. Pressed it for a good 5 seconds. Got a green flashing light. Had the drives in the all the way up position before starting. Did this with out using the all up drive button on the throttles. I used the individual drive buttons to get them to the top. Once I had a green flashing light, I held the all drives button in the up position for about 6 sec. Once that was complete, I moved them individually all the way down. Do not use the all button to move them. Move them one by one, using about a second or 2 before moving the other. Once you have them at the bottom, use the all down button on the throttle and hold it for about 3 seconds. That re-synced the drives to the system and all is good. I called Mike at MDC and he was awesome. Great product, great service!

Hope this helps others.

Thanks for the review. I'm planning on running Drive Guardian's on my new engines. Was considering this drive sync also.