I have a 2008 Explorer EB V8, and when driving in the city in drive at about 35-40 mph it shifts into the last gear and cruising on flat road the engine is kind of searching. The rpm varies about 250 rpm as if it is searching, like it won't hold a steady rpm for the speed. Like it kicks up a couple hundred rpm and back down to the other. I have had it on the road and it operates similar at higher speeds. Maybe it is ganging gears? 6 to 5 and back. It does good mpg on the hwy, about 23 at a descent speed. Maybe this is the norm? 97+ miles, just baught it in oct or nov. Thanks Geo

 

Sooo I should just run the truck with the OD not working in the city? And with OD on on the HWY only? Or maybe bring it in and have the computer checked? Out of overdrive it drops 2 gears to fourth, for better city driving. Maybe it's the norm, to drive city out of OD and fourth gear as highest?

 

Sorry, I dont have an explorer, but my 2010 f150 at work does the same thing. At those speeds I very often use the tow/haul mode to keep it in a lower gear.

It could be hunting gears, it could be locking/unlocking the converter, or it could actually be slipping for a second until the computer tells the trans to raise the pressure.

Whatever causes it, toe/haul helps.

 

Thanks, that's what I have been trying to do also. Hard to get my head around running it out of OD into Tow-haul!! But it will be better on equip in the long run I think. Might be a lot more folks doing the same thing...Thanks again...

 

Its prob locking and unlocking the converter.

 

Thanks, I have been running it out of overdrive and that works. Something new, every once in a while it sounds like I'm driving over rumble strips. Today it sounded like the front tire was going over some maybe I'm getting paranoid. If anything bad is going on in one of the gearcases and I get the lube changed it would show some sprinkles, if it was wearing? At 97000+ miles they need it any way rite?

 

in my experience, that rumbling you describe is usually the torque converter clutch. Try to take note of when you hear/feel it. if it is shuttering when the RPM's are dropping, pretty good bet that it is the torque converter clutch causing it.


new fluid might help, and it might even solve it completely. but regardless, new fluid can only help.


I would do a transmission flush at that mileage as a matter of basic maintenance, even though the manual doesn't call for it until 150,000. You will have to find a shop that can do a heated fluid exchange since your transmission has a thermostat. Failing that, the best you can do is drop the pan and replace the fluid about 3 times in succession which will get 90% of the fluid replaced.


There are some types of exchange machines that remove the filter and add the new fluid with an adapter in which the new fluid goes into the transmission in the same way it normally would and the old fluid spills out over the valve body into a catch pan. this type of system would also work, but I can't find any videos showing the type of machine I'm talking about.


a cooler line exchange won't work unless the new fluid going into the transmission is hot enough to keep the thermostat open.


serving ideas.

 

Thanks, I will call the local Ford dealer and see what I can find out. Do you know what temp works the thermostat? I may be able to do it myself, need to drain, drop pan, replace pan three times. Operate it for a few miles between for good mix and temp to come back up. But I'll call the local ford dealer first, to see if I can get a hot trans oil change. I'll let you know what is found out. Thanks for all the info. I would like to tow a camper with it.

 

180-185 and the thermostat should be fully open.

Getting the trans up to temp is fairly easy, getting the fluid going back in hot enough to keep the thermostat open is the hard part.

The dealership will be your best bet for a heated flush, but not all dealerships have one either.

Other than the mess, dropping the pam fluid a couple times isn't a bad way to do it IMO.

 

Thanks again, I'll check tomorrow. .

 

I normally put it in gear with the park brake set to heat the fluid when I do a flush. My shop doesnt have the heated machines but once I get the fluid hot enough it flows fine.

 

Thanks, I just dropped it off at a good shop with a heated oil filling machine. They are going to check codes and drop pan. So I will get a new filter and oil. We went over the thing so I knew he understood what I expected to get done. He is going to call me tomorrow when he pulls codes if there are any. Should take care of it. I'll post the results if any codes, and the oil change. By any chance you don't know the value of any trans codes? Just askin...

 

Had the trans oil changed and it is doing the same thing. Every so often it sounds like I'm going over rumble strips and the engine is searching between gears 5&6, I'm told there are some clutch discs in the transfer case, and they might be the culprit. Any thoughts on this? Thanks Geo

 

it can take some time for the new fluid to work into the clutches, so it may get better. that being said, you usually see an immediate improvement even if it's not 100%


there are clutches in the transfer case, but they should only be engaging if you are in Auto-4 and there is wheel slip detected.


the front hubs (IWE's) could be suspect as well, but those usually sound like rocks bouncing around in a coffee can.


it is possible that there is a problem with the trans that can only be fixed by removing it and, most likely, replacing parts (like the torque converter) or rebuilding.


I'd be very suspect of a problem with the torque converter clutches.

 

I'll keep driving it and see, maybe some time will tell. It's an AWD and not in high or low at any time, on auto. I also thought it was an improvement...time will tell. I'll keep posting, thx. Geo