Getting A Intermittent "Clunk" when Shifting Into Reverse !

Old Aug 15, 2022 | 05:25 AM
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Getting A Intermittent "Clunk" when Shifting Into Reverse !

For some time, I get a Clunk when shifting into Reverse. It seems to happen when on a slight incline (like my Driveway). I have the Parking Brake Engaged and seems to be a bit worse when the starting a Cold car (even in the hot weather). I just brought it to the Dealer last week, left the car with a Loaner. The Tech and Service Advisor could Not duplicated the "Clunk". The advisor sat in the car with me, she on the driver's side, and shifted the MDX into D and R a number of times. Then she shut the car, restarted, and still no Clunk. I left scratching my head? When I got home, parked in my driveway, and shifted into R and bingo - the Clunk was there!! I noticed that the advisor was prevented from moving the car in R because She did not have the seatbelt ON. That is a Safety feature, if you Shift the car into R w/o wearing your seatbelt (Driver), you cannot proceed. When I tested it in my driveway I was wearing the seatbelt. I called the Advisor, informed her of this, she was WOWed by this fact. Told me to return for a retesting with a Tech. This time I will be in the car with The Tech.

Anyone else experience this?
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Old Jan 22, 2023 | 10:23 AM
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Have had same issues in my 18 TLX, 11 MDX and 23 MDX. If you park on an incline, put it in park before you apply the parking brake, all the 'weight' is with the transmission. Trying putting the parking park on before you release the brake, while putting the car in park. When you go to leave, keep foot on brake, release parking brake, shift to R or D, then go. Should be no clank
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Old Mar 20, 2023 | 06:12 PM
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Did you resolve this issue?

Almatti - Did you ever get a resolution to this issue? I have the same issue with my 2001 MDX. I don't park on an incline but when starting up and shifting into reverse there is a big clunk once in a while; not every time. I can feel the shock in while sitting in the drivers seat. And after the initial clunk, it shifts smoothly in reverse the rest of the trip.
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Old Oct 9, 2023 | 11:17 AM
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For what its worth I did replace the rear motor mount and it was broken. I am still putting it back together so I can't confirm if it solved the clunk problem, but I am feel'n good it will.
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Old Jan 29, 2024 | 05:53 PM
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To update, replacing the rear motor mount reduced the clunk, but the clunk when shifting into reverse (only in the morning) remains. After the first clunk in the morning, the shifting in revers is very smooth. I am going to replace the 3rd clutch pressure switch due to other internet research. Will update.
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Old Jan 30, 2024 | 05:38 AM
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Waukesha, I just saw this post (after getting an email notice). Similar to your post, the "Clunk" is intermittent - mostly prominent when first starting in the day. If I use the E Brake engaged when I turn off the car the day before, it does NOT happen. My MDX is parked in a driveway with a slight (maybe 10 degrees) incline. I don't recall if this Clunk happened immediately, but I experience it now. This never happened to all the Numerous vehicles that were parked there. Some posters have said that it is the Parking Pawl. After my visit to the Dealership last year, The Service Rep, sat in the car with me, parked on their lot, and we shifted into P and R numerous times. The Clunk could not duplicated. You know the rest of the story....."There's Nothing Wrong". But when I returned home after the visit, parked in the same spot, and shifted into R - it Clunked slightly. The MDX was fully warmed up. You may be onto something with the Post of this problem . Was there a TSB issued? How did you find it?
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Old Jan 31, 2024 | 06:01 PM
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Almatti - Thanks for responding. I wish I had a great explanation for trying the 3rd clutch pressure switch but I don't. Research revealed other Acura vehicles with the same issue that replacing a clutch pressure switch fixed the clunk. In those cases, they claimed R shifting was tethered to another drive gear. I looked at the service manual and indeed the R gear is connected with the 5th clutch....however, there is no 5th clutch pressure switch on my 2001 MDX trans. My trans has 5 gears but only a 3/4th clutch pressure switch. Then I came across this post for a 2017 RDX. Yeah, its a different year, make, and model, but its an RDX and the fix was the 3rd clutch pressure switch. Its an easy swap, so I figure I'll give it a try. Yes, this is the cannon option, but given I replaced the motor mounts and this only happens in the morning on a cold start leads me to believe the problem is a solenoid or something mechanical that is sticky while cool and once its engaged is loosened up to work find thereafter until it cools overnight. And this fix is consistent with my theory. I will of course update and maybe this will be your fix?
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Old Feb 18, 2024 | 02:16 PM
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Confirmed - the 3rd clutch pressure switch did NOT fix the 'clunk.' My hypothesis is there is a sticky solenoid associated with reverse since it only clunks once in the morning on the initial shift into reverse and then works great the rest of the day. In the morning if I let it run a few minutes before shifting into reverse, it shifts fine (smooth). So I replaced the trans fluid (which was brown like motor oil) and will change it again in a few hundred miles with the hope the new fluid may loosen whatever crude may be causing a solenoid to stick. In the meantime I will continue to let it run a bit in the morning before shifting to reverse.
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Old Feb 19, 2024 | 05:10 AM
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Waukesha, THX for diligence pursuing the explanation and Fix for this Clunk. Mine is Intermittent. Happens going into Drive too, If I'm on a slight decline , even after a fully warmed up engine and taking a trip. On my next dealer visit, I will again mention this issue. I think it's faulty or overzealous Parking Pawl. I'm no Rookie with cars, having had many over my 55 years of driving, but don't recall any acting in this manner. Parking on surfaces with more inclines or declines (small hills, I.E.) - than Yes, The Parking Pawl would "clunk". I would like to get to the bottom of this issue, for my lease comes due in August, and May Buy my MDX with a buyouit of $38,500. It will have maybe 25K miles on the clock by then - 17K now.
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