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Discussion Starter #1
I got another issue. That stomp me that I notice yesterday evening (after 6pm). When I put the family MDX (2006 model) from P to D5 or N to D5 it engage twice meaning it lunges (hard jerk) forward 2 times after that It drives so well. It does not do it from P to R. or any other D gears except for D5 only. I also notice it when the motor is at operating temperature. I asked my wife about it and she said it drives fine with no issue (she drove it that morning).

I checked the transmission fluid it's got a little red to it does not smell burnt and the fluid is where it should be on the dip stick (I checked it while the motor is at operating temp). By the way no CEL lights on and D5 is not blinking.

I'm changing the trans fluid and transfer case fluid today with Honda fluid. Hope this will help are do you think it's the transmission pressure switch going bad or something else? The motor and transmission mount been replaced few month ago. The VMT-4 fluid been replace the other day along with the VTM oil temp sensor and upstream 02 sensor.

EDIT:
Wife took it out this morning she said no issue with engaging. That tells me it only does it when the fluid is at operating temperature.
 

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From the description, it could be a motor mount, in which case what you're feeling is the slack in the motor mount being taken up. FWIW, there is kind of a subdued "double bump" when you put an MDX in gear. I put mine in N most often when I pull up to a stoplight (if it's going to be red for a while). When I put it back in D5, I can feel two "engagements". It's not a "lunge" but with a bad motor mount, and the right conditions, you could very likely feel both of them much more than with good motor mounts.

And of course, it's always possible that there is a misbehaving shift solenoid (or other similar valve) that's keeping one of the clutches in the wrong position a little too long when you engage D5. A fluid change is the best thing to do (on a number of levels) and might clear up a problem. I'm a big fan of inline magnetic filters, to help out the aging internal filter that's likely losing its ability to trap particles) as well as adding a little LubeGard Platinum to the fluid (I've seen it "fix" transmissions that had loads of problems).
 

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Discussion Starter #3
I changed the transfer case and transmission fluid last Friday. It look like it solved the issue. I don't feel it engaging anymore but I notice I hear (2) clicking sound like it could be (2) relays you have to listen in carefully (maybe this is normal). It drives so much better and all the shift point are very smooth.
 

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You're probably hearing shift solenoids engaging (they're not "noisy" but you can hear them, or at least feel them engage).

Congrats on a "cheap fix". Our trannies do love clean fluid. You might want to consider doing another fluid drain and refill again soon, just to get more of the old fluid out.
 

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Mine will lunge forward slightly 2X when shifting into any forward range from P,R or N. It feels like the normal movement when one would shift into D in any other vehicle, except it happens twice. I just wait an extra second before applying any throttle after shifting. If I don't hesitate, and step on the gas immediately after selecting a forward range it will jerk forward. It does have the feeling of a bad motor mount, however I have inspected the mounts visually as well as brake torque testing and all is well. It is almost like the clutches and bands inside the transaxle are engaging at different times. This is only an issue when initially shifting into Drive, and there are no other issues with the driveline at any other times while driving. It has been like this for at least 100K miles so I'm not concerned.
 

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Mine does that, too (I think it has since I bought it with 160,000 miles (now at 215,000). I also just wait an extra second to take off after shifting into gear. I suspect it's normal, but am not worried about it if it isn't.

I'd be curious to hear if others have (or don't have) the "double-engagement" when shifting from P or N to D. It's very subtle, so it could be that it happens and you don't notice.
 

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Is that from a complete stop? Or in the middle of a maneuver like pulling out from a parking spot?

Do you get this when driving in D4?
 

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I only notice it from a complete stop. Can't say if it occurs going into D4, but I suspect it does. The second "bump" is very subtle - you can't really hear it, and can barely feel it, but something down there is changing states after the first more "normal" bump when first moving from P or N into D5.
 

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Discussion Starter #9
Another update.
It's working perfectly but planing to do another transmission fluid and Transfer case fluid maybe sometime in July or August.
 
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