2007 4.6L rumble strips at 45 MPH - potential fix?

[rober01c]

I've read several posts on this topic and suffer myself from a rumble-strip-like feeling in the front of the vehicle when driving at 45MPH or so but only when my foot is barely on the accelerator to maintain speed. Doesn't happen when coasting or accelerating.

I took it to the mechanic and they suggested flushing the transmission fluid. We did that and the rumble-strip problem went away. Two days ago. So it may come back. Who knows.

Anyone else with similar experience? Is this wishful thinking? Do I need to trade it in before the tranny goes?

 

[Bill MacLeod]

The 4 speed auto used in the 94 to 04 Mustangs (aode/4r70w) had issues with torque
converter shutter. This riding over a rumble strip feeling would usually occur at around 40 mph or so during the 3 to 4 shift under very light throttle pressure. Cause was supposedly worn out fluid. (Breakdown in the friction modifier and/or overheating of the fluid)

Fix was to do a pan and torque converter drain, use Mercon V and add an aux cooler.

So if you were experiencing converter shutter, then a fluid change was the correct first step

How many miles on the fluid when you did the change and what fluid did you put back in ?

 

[rober01c]

Thanks for the reply! The engine probably had the original transmission fluid and the mileage was 82k. Not completely sure but I am the original owner and don't remember having it changed.

Not exactly sure what was put back in but know that my wife paid a premium versus a typical flush due to the special fluid required from Ford.

 

[Bill MacLeod]

If the "rumble strip" feeling was a regular occurrence and now is gone after the service, I'm going to guess that your problem is fixed. Sounds like the proper Mercon SP fluid was used in your 6R60 trans.
If it happens again and you have yet to have the trans filter changed, then I would suggest a pan drain, clean pan of slug, change filter and add new SP.
There is also a produce made by Lubeguard that many in the past have used for torque converter shutter with good results.

 

[swetrid]

Spark plugs

 

[rober01c]

Thanks Bill. I really appreciate the help.

For the other poster, I had the spark plugs changed about 6 months ago. Wife called me from 100 miles away, it was running rough. Had her go to the nearest shop. I almost fell on the floor when she told me how much it cost. But later figured out that's just how much it costs with these vehicles.

 

[tripplec]

How dark was the fluid before it was changed? I presume it was as a PAN DRAIN where the filter was also changed as "MacCleod" suggests. Are you towing a lot with it? These should have a factory tranny cooler if not its a must with a heavy vehicle like it. If it was the fluid I'd get the fluid changed again later on after some miles on it have accumulated. A pan drain only removes 1/3 approx. so you need several changes to mix in enough to affect it all. Since you had it from new its good you know the history. Fluid changes are cheap even if the fluid is expensive at first. But always use the specifiec fluid as stated (owners manual clarifies that) or you're going to ruin the tranny.

Currently driving a Grand Cherokee with 291k on it and I have changed the fluid at least 5 times so far. Its not cheap for its 7-9$ per liter fluid but you have to use it as well.
Good luck with it.

 

[Tech By Trade]

If its a 4x4 take a real close look at the front drive shaft U-joint.