Transmission Fluid Level- Park Vs Neutral

[Matt]

So it's been evident for a while that the trans dipstick says to check the fluid level in Neutral while the FSM clearly says to fill in Park. There's been discussions ranging from "it doesn't matter" to "it has to be in Neutral" to "it has to be in Park".

Well, since none of us are Mopar engineers, I figured I might as well go right to the source and try to get an official response.

I'll keep updating this first post with the responses. You'll see from my response today I'm expecting to get my inquiry moved up to a more technical/official representative...

Dear Matthew:

Thank you for contacting the Jeep Customer Assistance Center regarding
your inquiry on how to properly check the transmission fluid in your
2007 Commander.

The torque converter fills in both the P (PARK) and N (NEUTRAL)
positions. Place the selector lever in P (PARK) to be sure that the
fluid level check is accurate. The engine should be running at idle
speed for at least one minute, with the vehicle on level ground. At
normal operating temperature (approximately 82 C. or 180 F.), the fluid
level is correct if it is in the HOT region (cross-hatched area) on the
oil level indicator. The fluid level will be approximately at the upper
COLD hole of the dipstick at 70° F fluid temperature.

Be sure that the referenced dipstick is a factory dipstick and not an
aftermarket part added by previous owners.

Thanks again for your email.
Sincerely,
Tony

Tony,

Thanks for the response but I'm looking for a bit more clarification. I have both the OEM factory service manual and the complete 2007 Parts Manuals.

The dipstick is indeed the correct OEM part, 53013686AD. Being a 2007 model year I figured there would be a new revision to the dipstick, but as far as i can see that part number is still valid and has not been superseded.

Although the torque converter fills in both P and N, other XK and WK owners have reported that the levels measured are different. Hence the issue that most people are filling their transmissions based on what the dipstick says (Neutral), whereas the factory service manual clearly says to measure while the vehicle is in Park.

I'm surprised there hasn't been either a rev to the dipstick or a TSB issued to clarify the discrepancy yet.

Other than stating whats in the manual, can you verify that there will not be any transmission damage caused by being under/over filled if the fluid level is checked while in Neutral per the dipstick instructions?

Thanks,
Matt

Latest Reply....

Matthew:

Thank you for your email reply.

The best way to check your transmission fluid is by placing the gear
selector lever in P (PARK) to be sure that the fluid level check is
accurate. The N (Neutrtal) position is less accurate of a reading. The
dipstick will have markings listed to determine whether the fluid level
is within specification.

Thanks again for your emails.
Sincerely,
Tony

For the record, I just got home from running some errands and checked my trans fluid via both methods and the Neutral reading was higher.
When in Park: Fluid level just below the H in "HOT"
When in Neutral: Fluid level at the T in "HOT"

Both were within spec so I'm not worried. I'll probably use "P" from now on and just fill to 25-50% range of the HOT zone.