Hello all been reading for awhile need some help if you dont mind. I have a 98 dode ram 1500 5.9l 46re tranny.

She slips a little shifting between 1-2 and 2-3 . When cold she will go into OD but when she warms up she will kick out of OD and I cant go back in. Over drive light in dash does not work, it seems switch might or might not work hard to tell with out light and limitations of OD.

Will replace TPS today. Should I replace transmission speed sensor? Havent cracked pan and got a visual inspection yet but fluid is cherry red and doesnt smell burnt. No codes at all except a random upstream o2 sensor that comes and goes. I have tried the turn the key trick as well to no avail.

On a side note she also has the gasket/plenum problem, but im ignoring that for the time being while I tackle the transmission issue. Just to paint the whole picture.

Thanks!

 

Check codes before replacing any parts. Is the CEL on? Have you deleted the check valve? (DIY in FAQ/DIY section) Sounds like the trans is overheating, and disabling O/D. Or, you may have a short in the wiring for the switch if it isn't working properly.

 

So if you turn the key to "run" without starting and the instrument cluster checks all the bulbs in the dash, it doesn't illuminate then either?

 

Yes the light is burned out. I will change the bulb soon.

 

The only CEL i get is the upstream 02 sensor that comes and goes as it pleases. I believe it comes on because of the plenum/gasket problem. Right now atm its off completely and yes it does illuminate at start up. The check valve thing ill research on that for awhile thank you for the idea.

 

Is fluid burned smelling?

+1 on check valve delete.

Problems from plenum can create symptoms on shift as you are experiencing due to engine lugging. Not often diagnosed as such, but it does happen.

 

No the fluid is bright red and smells just fine. I did the research on the check valve delete and Ill do it either today or tomorrow and update. Thank you for your advice!