My speedometer started acting up a couple of weeks ago, swinging from 65 down to at times 10 mph, then would jump back up to normal, and twice, just boogying down the road, it jumped out of OD, I don't mean dropped down to 3rd, but like it was in nuetral, both times I stopped, and shifted it to park then back to drive, and all was fine. I was booking down 78 in the midst of stupid people putting on make up, taking out rollers, and talking on cell phones when it did it again and I almost got creamed by a coal truck that was looking at some legs and something else that just about didn't have a skirt covering it, after a few choice words to him on the radio he opolgized and I turned my rear end around and went home. I figured the speedo cable was going bad, but when I crawled under it, it ain't got one, just some type transducer with 2 wires, and I found it was LOOSE. Tightened it up and so far, no problems, it's not hunting between 3rd and 4th anymore, but tranny fluid is light brown. Question is, is speedo wired to tranny thru computer to control shifting, and could this also be a reason for the 3-4, 4-3 shift problems. I HATE COMPUTERS ON VEHICLES, unless it's my laptop plugged into the gps so I don't get lost

 

Yes, the computer looks at the speed sensor and throttle position sensor for OD engagement parameters. If you were cruising at a good clip and it decided to jump out of OD it might feel like your in nuetral because of the RPM change (very high) and the pump defueling at that RPM. It was prolly just in 3rd gear above it's RPM/fueling range.

Drop your pan and change the filter and fluid. Filter/Gasket set is under $20. Change the fluid which usually is around 6 qts dropping the pan. Drive it for a couple of weeks and do it again. I wouldn't flush it with a machine at a shop.

Den

 

Den- what fluid would you recommend as I will be doing the same soon

 

I just fixed last night my problem with the Speedo. A couple of years ago, my speedo adapter fell out of the speedo gear coming out from the tranny (little ball bearing holds it together and lost that). Lost OD right then and there. I tie wrapped with a piece of wire and secured the adapter from falling out again. Worked great until recently due to it snapping the square piece that goes into the speedo gear. I purchased a new OD Adapter from Dodge (about $60) and hoped I could get the broken piece out of the gear that was still in the tranny. No go, so bought that piece (about $75) and replaced the gear section coming out of the Tranny and the adapter that bolts onto it. OD now works without a problem. Love finally going over 55 mph or so. Just make sure if you order it that you do mention you have the NP205 transfer case (I assume you do, like me). They first ordered a gear that had 30 teeth to match my 3.54 rear gears/235x85x16 tires. I showed them that the gear has only 16 teeth and it looked more like a barrel with teeth at the end and not just a big geared tooth.