Can anybody tell me what is the average life span of a Thompson trim unit? I bought my mb sd used in February and I was told the trim would probably go out soon and it did so I changed it saturday. I never thought of asking how often he had to change it. I'm just trying to get an idea if any of y'all can help, thanks.

Usually over 100 hours. The seal that the shaft slides through is the culprit on the Thompsons. Keep some grease rubbed on the shaft/seal and youll squeeze a few more hours

Good to know on the grease, my motor had 105 hrs when I changed it so it's probably the first time, I'm guessing, thanks a lot.

Quack look around on the mb Site and there's a guy that told how he repaired his. It might save you some cash next time around.

Thanks med, I'll check it out, I know when I took my old one off the seal was dry rotted pretty bad, if I can make it last longer or fix it that would be nice.

The trick to keeping them going is to check the seal often. If it looks damaged or degraded pull the unit off and repalce the seal. Their only $8.00-$10.00 and a piece of cake to change. If the seal gets damaged the unit will get wet and take a shit. I am thinking I will change mine out once a year. Cheap insurance to make them last.