Transmission Feels Like It's Slipping

[sojodave]

I have an '06 Explorer with V8, 6 speed and I have weird problem that only happens a few times in a day. When accelerating from a dead start, the engine will rev up to 3K rpm, and it feels like the transmission isn't kicking in. I take my foot off the gas and it feels like the transmission has to catch up to the engine.

I took it to Aamco and they said no problem with the transmission and of course they couldn't get the car to duplicate the problem.

It's either a computer problem, an engine problem, or a transmission problem. It has 65K and I had the transmission serviced in the four months ago from a Goodyear dealer.

Anyone have any ideas?

 

[Ford Explorer9]

I have an '06 Explorer with V8, 6 speed and I have weird problem that only happens a few times in a day. When accelerating from a dead start, the engine will rev up to 3K rpm, and it feels like the transmission isn't kicking in. I take my foot off the gas and it feels like the transmission has to catch up to the engine.

I took it to Aamco and they said no problem with the transmission and of course they couldn't get the car to duplicate the problem.

It's either a computer problem, an engine problem, or a transmission problem. It has 65K and I had the transmission serviced in the four months ago from a Goodyear dealer.

Anyone have any ideas?

Is the car moving at all when you do this or does it feel like it's in neutral? I had a 1999 Dodge Ram that would do something very similar. It was extremely noticeable when giving it a lot of gas going uphill. It turned out to be the torque converter.

The truck did not have a tachometer but from the sound the engine made it would be around 4k rpm when going up hill and the truck felt like it had next to no power.

 

[sojodave]

My Explorer does move when it revs. It seems to happen more when I go down a hill than up hill.

 

[Old As Dirt]

Sounds like low fluid.

 

[sojodave]

Low fluid was my first thought, but Aamco said that all my transmission fluids look good.

 

[Ford Explorer9]

Hmmm... when initially accelerating from a stop does the truck buck at all? Like you give it gas, the truck almost hesitates like the parking brake is on and then off you go. Or something along those lines?

 

[sojodave]

The truck doesn't buck, but it sounds like it revs and doesn't accelerate even though I can rev the engine as much as it can take. I take my foot off the gas, wait a couple of seconds, and it feels like it can accelerate again. Last night, I drove 20 minutes before it happened.

 

[sojodave]

Tonight I tested the engine revving problem. I was able to accelerate the car forward. It was slow and I kept my foot steady on the gas and eventually the transmission caught up to the engine.

 

[Town]

As you accelerate can you feel the gears shift? The following chart is taken from the Ford manual and relates throttle position to gear to speed in MPH and KPH. The Ford 6r60 trans is smooth shifting but I can feel the shift points. Do these shift points seem correct (I cannot get the table values to line up-sorry)?

Throttle Position Shift mph km/h

Light Throttle 1-2 9 14

2-3 16 26

3-4 24 39

4-5 32 51

5-6 40 64

Closed Throttle 6-5 29 47
5-4 24 39
4-3 20 32
3-2 7 11
2-1 4 6
Wide Open 1-2 30 48
Throttle (WOT) 2-3 56 90
3-4 80 138

The next issue is the TCC (torque converter clutch). Untill the TCC engages the engine rpm is supposed to increase noticeably, that is the way the torque converter works. So after each shift up the TCC should engage and there should be direct drive in 2nd and up so rpm will increase slowly under light acceleration. So does the TCC get applied or is the engine free to rev?

As mentioned earlier a low fluid level will affect shift points and the engine will rev more than normal. The other aspect is the choice of fluid. Your vehicle needs Mercon SP so did your trans service include Mercon SP or something else? A related problem could be high fluid temperature and/or a faulty temperature sensor.

Here is a diagnostic symptom chart related to slipping trans:

"Shift Concerns: Feel — Soft or Slipping (Some or All) Possible Component Reference/Action
213 — ROUTINE
Transmission Fluid
· Incorrect transmission fluid level
· Check the transmission fluid level. Adjust transmission fluid to correct level. Refer to Preliminary Inspection in this section.

· Transmission fluid filter and seal assembly — plugged, damaged
· Install a new transmission fluid filter assembly.

Powertrain Control System
· PCM electrical inputs/outputs, TCM, external vehicle wiring harnesses
· Carry out on-board diagnostic tests. Repair as required. Clear DTCs. Road test and carry out on-board diagnostic test again.

Transmission Fluid Temperature (TFT) Sensor Damaged
· Mechatronic assembly
· Install a new mechatronic assembly. Refer to Mechatronic Assembly in this section.

· Bolts not tightened to specification
· Tighten to specification.

· Mechatronic unit contaminated, solenoid(s) damaged, stuck or bore damaged. Manual valve damaged, stick or bore damaged
· Inspect for damage. If damaged, install a new mechatronic assembly. Refer to Mechatronic Assembly in this section."

The issues related to the Mechatronic unit or valve body issues (solenoids, etc) may show up as DTC's in the TCM. Did Aamco check for DTCs when they said the trans is OK?

Good luck.

 

[sojodave]

I took it to the Ford dealer. Of course they drove it around and couldn't replicate the problem. Their guess was the throttle body should be replaced. $550. I told them that was an expensive experiment and said no thanks because they didn't know for sure that would cure the problem. It's bizarre because I even had the engine over rev in park.

 

[sojodave]

I took it to another Ford dealer and they think it's a transmission problem. I don't know what to do at this point.

 

[sojodave]

I took it to another Ford dealer, and they said my radiator needs to be replaced. They think my truck has been over heating which is causing the engine rev problem. At least this makes sense because it only happens when I have been driving it for 20 minutes. They quoted $980 for a new radiator, then called back and lowered it to $592. I told them, no thanks, already got a quote from a radiator shop around the corner for $440. We'll see if this solves my problem.

 

[Town]

I took it to another Ford dealer, and they said my radiator needs to be replaced. They think my truck has been over heating which is causing the engine rev problem. At least this makes sense because it only happens when I have been driving it for 20 minutes. They quoted $980 for a new radiator, then called back and lowered it to $592. I told them, no thanks, already got a quote from a radiator shop around the corner for $440. We'll see if this solves my problem.

Your vehicle has "fail safe" cooling that covers overheating of the coolant and the engine oil. When the PCM detects this condition, your temperature gauge will be reading in the red (Hot) area, it will command the check engine light on and the coolant warning light will be on. If the engine gets hotter then the PCM initiates the "fail safe" mode and reduces engine speed and power (limp home mode) and will shut down the engine if the temperature keeps rising.

Overheating ordinary engines run poorly and slow down due to a loss of power. While you may have a radiator problem it will show up in falling coolant levels or rising coolant temperature gauge reading or both.

Good luck.

 

[sojodave]

I've been doing some research and it looks like there is a TSB on the 4.0. TSB 09-8-1 for Coolant leak-radiator-built before 8/8/2006. I called the Ford dealership and they didn't know anything about a 4.6 engine having a TSB...but then again this is the same Ford dealership that has screwed me over and over again.

 

[Flag Gibby]

I've been doing some research and it looks like there is a TSB on the 4.0. TSB 09-8-1 for Coolant leak-radiator-built before 8/8/2006. I called the Ford dealership and they didn't know anything about a 4.6 engine having a TSB...but then again this is the same Ford dealership that has screwed me over and over again.

Yes, the TSB is only for specific years of the 4.0. I thought that there was a TSB out for the 6 speed that changed the transmission programming and resolved a lot of the shift issues. The most common thing to go bad is the solenoids on that transmission (see the expedition complaints about the six speed), but you could try just cleaning the throttle body and MAF sensor to see if that changes anything since it doesn't hurt anything and may make it idle/run better.
I also noticed that you said you recently had the fluids changed, if the shop didn't use ford spec. equivalent fluid then it is not viscous enough (too thick) and it is taking too long for the clutches to engage and disengage.