2000 Isuzu trooper transmission sutters going into over drive. Do i need a new transmission?

This is Stanford from Aamco transmissions in Englishtown. How long has the vehicle been doing this and how many miles are on the car? Is the check engine light illuminated? It is a possibility that your transmission is failing and you may need to repair, replace or rebuild it. It could also be an electrical problem. The vehicle would need to be inspected to determine if this is a minor problem or if you have a major transmission issue.

I just bought it. Yes the light is on. And it has 188,000. But drives great, when it goes to shift just let off the gas, and it changes,and goes on.

Sounds like a possible electrical issue. You should have it scanned and see what codes are present. The condition of the transmission fluid should also be checked. Let me know.