Suprised to discover Isuzus much touted TOD system is not part of the Drive Train. Makes me think they are Lawyers not car Builders.

You should have cleaned your EGR Valve & changed your PCV Valve every 3000 miles. Lubricated your windows every week-Siliconed your headlight Gaskets every month- Removed & adjusted your CD player after each use . Line Xed your insert to prevent cracking- Replated your wheels etc etc.

If I could get a Xfer case ( Salvage) for less than $300 I would do that.

By the Way "Happy Birthday"

Bob F