2008 limited AWD overdrive slips

[joeskisnow]

I have a 2008 limited AWD. A few weeks ago, when driving normal speeds on the city streets, when i go to accelerate even a little the transmissions starts jerking like it is trying to downshift. There are no codes and the only way I can stop the jerking is to hit the overdrive button and cancel the overdrive. I took it to a transmission shop. They experienced the same issues but could not get any codes or anything crazy on the diagnostic machine. They offered to rebuild it for 3k, of course. The shop said the fluid was good, not burnt or messed up. Any suggestions?

[WWWPerfA_ZN0W]

What is the maintenance history on this Edge? How many miles? Have spark plugs and PCV valve been replaced yet? Is fuel injector cleaner used regularly? Are the throttle body and MAF cleaned regularly? When was the air filter last changed?

 

Definitely sounds like it is hunting for a gear. You should get diagnostics done at a fullservice shop or maybe even at the dealer, they should be able to use IDS to deepdive into the powertrain. Could be needing new TSS/OSS sensors if the problem is indeed in the transmission. New fluid should be installed (Motorcraft Mercon V, or other brands CERTIFIED Mercon V would be a good start). The O/D "fix" might work for now, but that will also stop working in due time. Maybe the torque converter is not locking up properly, in which case, the TC could need R&R. You can watch TC activity using an OBD code reader and Forscan software on a smartphone/tablet (Android/iOS/Windows). A cheaper fix might be wheel speed sensors, but that is more likely to throw a wrench light.

 

I hate to mention the PTU/driveshaft/RDU, but you gotta have those looked at to see if the fluids are maybe gummed up and/or leaking. Take it to a BG shop and they can figure out the driveline for you (look for shops with the driveline service symbol).

http://bgfindashop.com

[WWWPerfA_ZN0W]

Ford remanufactured transmissions (3yr/unlimited mileage warranty):

http://www.fordparts.com/Products/PowertrainProducts-RemanufacturedTransmissionAssemblies.aspx

Pricing (before core charge)

https://secure.revolutionparts.com/levittown-ford/ford/edge/8t4z7000arm/2008-year/limited-trim/3-5l-v6-gas-engine/automatic-transmission-cat/automatic-transmission-scat/?part_name=transaxle

 

Jasper remanufactured engines & transmissions are also an excellent choice.

 

You'd have to ask though if TC is included ...

[joeskisnow]

Thanks for the comments/questions. I have just returned from a deployment. The edge has 130k miles. The engine was changed while I was gone due to a bad head gasket for an engine with 79k miles on it. None of the maintenance you asked about have been done to my knowledge. I guess I will start there and see what happens.

 

The vehicle only seems to be hurting at low speeds. At highway speeds, 65-80 it does fine. The shop I took it to, B&M transmission, said they did a full diagnostic and came up with nothing.

[WWWPerfA_ZN0W]

Thank you for your service Yeah, I'd get basic maintenance out of the way. Who did the engine replacement, btw? You might want to give them a call also, see if they can give the install a once-over to make sure everything (including wiring) is set up correctly.

[joeskisnow]

You're welcome. I will reply to this post when I have the basic maintenence completed and see how things go.

[Serge1331]

I have the same issue for a 2007 Edge that i just bought. Let me know what you find out.

[joeskisnow]

So, something worked. I installed new plugs, used MAF cleaner to clean the MAF, installed a new air filter, changed engine oil/ filter and changed the transmission fluid. When I added the new transmission fluid I also added some lucas oil to help condition and stop the slipping. While I was installing the new plugs I also cleaned the butterfly valve (throttle body). I took a small test drive and had no issues. My wife drove her usual route around town and had no issues. Tomorrow we will drive further to see if I still have no issues.