I have a 97 dodge ram 2500. Sometimes my transmission doesn't work good and also my speedometer doesn't work at all.

The speed sensors should be on your transmission

You mean the speed sensor in the transmission, right ?
Not the wheel sensor. The wheel sensors are for the ABS system.

Have the system scanned for fault codes, I think you may have a defective VSS (vehicle speed sensor), but don't replace it before you have the fault code test run, a defective computer and or wiring to the VSS can also cause the same problems.

it could be any number of things, i would try having the transmission serviced first. the transmission filter could be getting clogged making it work harder and therfore making it shift differently.

There were a total of 5 Transfer cases for the four wheel drive Ram. All were part time and had a low range of 2.72:1. The 1500 featured a NV231 and NV231HD. The NV241 was standard on V8 2500 Rams. The 2500 and 3500 V10 and Diesel featured a NV241DLD from 1994-1997. In 1998, the NV241DHD became a option for all 2500 Rams and was standard on 3500 Rams from 1998-2002. Hope this helps so your going to have to find out which one you have NV231 or the NV231HD. Good luck

Review the autozone.com site (free register):

• Maintenance Interval Charts
• Routine Maintenance And Tune-up
• Serial Number Identification
• Servicing Your Vehicle Safely

After of register, select year, make, model and engine to access the inf about your vehicle.

Hope helped with this (remember rated this help) Good luck.

Could be the solenoid on the starter. Next time it doesn't start, hit the starter with a hammer or other hard object, then try to start it. If it starts, replace the starter before it leaves you stranded

Batteries should be changed as a group. over time they seem to "twin" off each other and wear at the same rate. You should also check your starter selonoid to be sure it is working correctly and is not worn out.

you may not have power or ground to your 1708 conector

When was last fluid & filter change done ? Mileage then & now?