Hi All,

I have noticed recently that my transmission is shifing "differently".

Truck runs great overall, no codes and SES light is not on (plugged a tester in to confirm no codes or stored coeds).

The Sport Mode is not on.

It shifts from 1st to second as it always has but it seems to stay in second a lot longer than it used to.

It will shift in to 3rd at approximately 1900 RPM and then into 4th at 2000 RPM.

I replaced fluid and filter about 3000 miles ago. Fluid still looks good and is not low.

Any thoughts on what may be causing this change?

 

Mine is doing that too.
Do you note:

When the rover does this:

A/C is on.
It is over 90 degrees out.

The cooling fan - large fan will roar when you press the gas.

I think the ECU is keeping the Rover revving higher to pull cool air through the system to cool it down.

the ECU knows the engine is starting to heat up and is cooling the engine
via changing the shift points.

Your ZF 4HP22 has wiring from the transmission control box to activate the
shift solenoids at a time of its choosing.
This is what is meant by "electronic Transmission".

On a Discovery I the 4HP22 uses pressure and speed from inside the transmission itself. Old style old school.

Welcome to the "new school".

 

How can you tell the fluid is not "low"?

 

At the trans fill plug with the engine running. (not real owner friendly, Rover figured their "upscale" owners shouldn't be bothered with this task)

 

Ahhh, I was hoping you had found a secret dipstick hole . The first time I replaced the fluid I did it improperly, so I went back 2 weeks later and replaced the filter and gaskets, filled it up while it was running. Plenty of fluid now, and no more weird shifting or stuck torque converter solenoid issues!

 

Hi Jfall,

I understand what you are saying but in this case the change was noted even in cooler morning temperatures.

I live where it is routinely 90+ degrees during the day and into the 40's or 50's in the morning.

The change in shift points I am experiencing is consistant regardless of the outside temperature and the shift points now always occur as I described.

It just seems like it is holding 2nd gear longer than it should now and that it shifts from 3rd to 4th too quickly.

Any other possible reasons you can think of?

Thanks

 

Your truck has 110,000 miles on it, is may be showing it's age a little.
When you said the oil looked good, better describe that, is it bright red or brownish, does it have any slight burned smell to it and how often do you service it?
The shift points are computer generated and other then cold starts, are not effects by ambient temps.

 

Hi Mike,

The color is nice and bright and there is no burnt smell at all.

It may be "normal aging" but with aging, would it be normal to see the seperation between the shift from 2nd to 3rd and the quick shift from 3rd to 4th?

The only other change I can think of is that I drive the vehicle very little now (20 miles a day maybe 4 times a week with very little freeway driving).

Would the computer adjust or react differently under htese driving conditions?

Thanks

 

Just to add:
My D2 shifts at 50 mph into 3rd then into 4th at 55 mph. It still drives, isn't throwing codes, and not jerking so I'm not worried about it yet!

 

what happens if you do put it in sport mode? do the shift points change as they should or do they stay the same?