If you take the two nylon bushings out of the lever, you DO NOT need to remove the rubber seal and bezel. The lever just slides off the shaft quite easily.
I was one of the first to do this modification. AND FOR ME, it's been the FIX! I plowed two days ago for over two hours and never once did it jump out of either forward or reverse. If the cable system has been really abused, and the unit has been jumping out a LOT, this may not fix the issue. It's very possible that you might have internal issues that only new parts can fix. But be rest assured, that if you do not do the 3/4" extension on the lever AND replace new parts internally, you will be right back jumping out of gear all over again.
Most anyone can take the lever off and take it somewhere to be extended. Even realigning the cable bracket after the lever has been extended, is quite easy to do.
Good luck! I'm VERY happy with my little UT400. I cannot believe how much snow this thing can push with the 60" wide blade. Because of my driveway size and shape, getting out every few minutes to change the angle pin, was not an option. I bought the hydraulic power angle upgrade and installed that. It's not the fastest to change angles, but it beats getting out to do it. I also upgraded to the fabric vinyl enclosure. In 10 degree weather with some wind, I can plow in tennis shoes and not have to wear gloves. Have not installed an auxiliary heater... Yet.:)
Dan Lockwood, Clare MI.