Weird transmission problem

I've done a lot of searching on the web and I cannot seem to find a problem like this anywhere.

2002 4.7 2wd 45rfe w/140k. Transmission jerks while driving in 4th and o/d. Worse when going uphill or accelerating. Been doing this for a couple months and is getting worse. Also, fuel mileage has dropped down to about 9 mpg. Thought it was a misfire when it first started but it is definitely comings from the trans. Last service was about 20k ago, and it was filled with the appropriate molar fluid. No codes thrown. I figure the trans is probably shot but if there's a chance of fixing it I would like to try.

Anyone else had similar issues?

replace your TPS - throttle position sensor. Shop around as prices vary from $40 to over $100 (dealer). A bad/faulty TPS is commonly misdiagnosed as a faulty transmission.

The TPS is located on the throttle body, you might have to remove the air intake to replace it. My 5.9L TPS uses two small hex bolts to hold it onto the throttle body.

It's also good to clean the IAC - idle air controller if equipped. The IAC can get gummed up with carbon and lead to sticking, which will result in an uncontrolled idle, and can sometimes affect how the TPS operates.

http://www.biodsl.com/durangofsm.htm

That makes sense. I can see how the TPS could cause some of these issues. I will replace it next week. I found it at Autozone for 32 bucks. Thanks for the tip, I'll let you know how it goes.

Sorry it took so long to get back. Weather has been crap lately. I put on a new tps and cleaned the iac out. Still having the same issue. Wondering if there is anything else it could be. If not, I'm on the hunt for a new trans.

Try driving it for a bit with the overdrive locked off. It won't help mileage, that much is certain, but if it doesn't slip it might be a solenoid. I'm not well versed in the 5/45RFE transmissions. Perhaps someone will chime in ...

I have driven with OD off. Problem still exists.

Try some Dr Tranny shuddering fix. Amazon.com sells it for about $7.00. Lubegard transmission protectant is also good stuff.

http://www.amazon.com/Instant-Shudde.../dp/B0007ZDRVC

http://www.amazon.com/gp/product/B00...N658SZHYA0SY4P

You can page around the FSM for a possible solution. Again I'm not too familiar with the 5/45RFE transmissions..

http://www.biodsl.com/durangofsm.htm

I have the exact same problem, I thought it was misfiring and replaced all my coil packs, plugs, crank sensor, cam sensor, tps, iac, and air filter. same probs I just reset the com and added some lucas tranny fix. I'll see how that goes.

Sorry for the lateness.. I've been super busy.

Anyway I had this same issue but from 1st to 2nd gear or something like that. Anyway come to find out there is a TSB about it being the TCM (Tranny control unit) being at fault and needs a software update. I did the first though with the TPS, tranny flush, and all that good stuff.

After a little research I learned you can swap the TCM with one out of a Jeep. I got my TCM out of a 2004 Jeep Grand Cherokee from Car-Part.com for $45 shipped. This turned my 4speed auto into a 5speed auto. And best of all it cured my problem. Dodge wanted $200 to re-program my TCM per the TSB dodge issued out.

This may or may not be your fix. But if anything it's a great mod. I now get about 20-22mpg on the highway.

If I remember right it only works for the 4.7 V8 in an 01/02 Durango. The 2003 Durango came standard with a 5speed auto (same tranny, just upgraded programing).

Make sure if you do order or locate a jeep TCM it has the part number matched below (match the larger letters and numbers)

yeah, I went to carparts.com and have had no luck finding the TCM or transmission control module for the cherokee. I would like to do this mod but the website sux. I do a search for tcm on 04 grand cherokee nothing but AC parts