i have an 01 duramax, i ordered a set of gauges and the only one i cant figure out is the transmission temp, it came with 3 different fittings but to be honest im completely clueless on what to do.. help??

 

Use the one GM provided in the cluster........

 

The three different fitting are just adapters for a size of your choice. You will have to drill and tap your pan and have the adapter welded or brazed to the pan. If I recall you have to use one of the adapters so that you are not welding the sending unit.

 

is the stock one broken or something?

 

stock reads 280 at all times.

 

sounds like the stepper motor in the cluster is bad......