IMHO, a clutch assembly is only as good (longevity) as the conditions its exposed to....with normal driving, the assembly should last 100k miles......since you are saying that you have to shut the engine off to get it in gear, I'm guessing the TO bearing or the hydraulic line to it has failed, otherwise, you would be experiencing grinding, chatter, or something along with this. depending on mileage & clutch assembly wear, assuming it's the TO bearing, this might be a much less expensive fix, especially if the clutch assembly is showing little to no wear.
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