Been driving it for 2 months. Rpm on hwy is rock steady. I would expect the Rpms to vary a bit? The pressure accumulator locks the clutch pack together so there should be no slippage at cruise. My trans is slipping 30%? You would think it would burn up fast due to the heat or stress on clutch plates? I wonder what is really happening inside.

 

I'm still thinking your transmission isn't making it into 4th gear. I know you've said otherwise, but the RPMs you've reported are right bang on what they should be for 3rd gear.

 

I thought I posted my Rpms at 40mph in 4th and 3rd?
Seems to me it was 2k in 4th at 40mph
And than it went up to 2700 in 3rd at 40mph
If I am not in 4th, than the rpm should stay the same in 3rd?

 

Torque converter lockup could explain the change in RPM.

 

If trans is not shifting into 4th, should I have a D4 code issue?

 

That I cannot answer.

The fact is, there are only four things I can think of (listed in order of most likely to least likely) which will cause your issue:

1. Transmission is not going into 4th gear.
2. Transmission is going into 4th gear but the torque converter is not locking up.
3. A previous owner changed the final drive ratio in the differential to shorter gearing.
4. The tires you're running are way-way smaller than the factory 205/65 R15 tires.

 

I sorta disagree with #4, as long as you're using the car's speedometer & tachometer. Smaller or larger tires won't change the relationship between speedometer & tachometer. It will only change the accuracy of INDICATED road-speed vs. TRUE road-speed.

 

I didn't remember if he was using the speedometer for his speed measurements or using a GPS device of some sort. That said, I listed them in declining order of likelihood, #4 being the least likely.