[Nuke]

How many miles on the car in question?

Im assuming it’s one of the Challengers listed in your signature, and both have the same transmission (assuming auto A5), but what about the rear-end on the car with the noise, is it an LSD (Getrag) or open diff (?) in the clunking car?

 

[daly double]

2014 RT Auto....108,000 miles...
Not sure how to answer your other question..

 

[Nuke]

2014 RT....108,000 miles...
Not sure how to answer your other question..

that’s fine, it’s likely 3.06 rear-end with open diff design...the clunking could be coming from the pinion flange to transmission output shaft connection. If there is play between them, it will make noise, but usually in both directions, not just reverse.

IDK,I’d say just monitor it for any changes in intensity and frequency. If it gets worse in either aspect, take it in to have them diagnose and fix if possible.

 

[daly double]

I think it does CLUNK when cold when going from Park to Drive also....I probably just notice it more from Reverse because I always back out of driveway..

If it's what you say....is that an easy/cheap fix at a transmission shop?

 

[Nuke]

I think it does CLUNK when cold when going from Park to Drive also....I probably just notice it more from Reverse because I always back out of driveway..

If it's what you say....is that an easy/cheap fix at a transmission shop?

Any auto shop should be able to check the play at the pinion flange on the back of the trans, doesn’t have to be a trans shop. Heck, you can do it if you get the car up high enough. Just grab the driveline where it bolts to the transmission and twist and pull/push to check for movement.

If play is found, that big but holding the yolk to the output shaft probably needs torquing down, but that requires a really big torque wrench and lots of room to crank on it, so you would probably not be able to do that in your driveway

 

[daly double]

Let me re-phrase....It clunks when I shift the Gears from Park when cold....To get to Drive...I have to move it past Reverse...and at Reverse is where the CLUNK occurs....Hope that makes sense..

 

[Nuke]

Let me re-phrase....It clunks when I shift the Gears from Park when cold....To get to Drive...I have to move it past Reverse...and at Reverse is where the CLUNK occurs....Hope that makes sense..

can you record a video and share that so the sound can be heard 1st hand?

 

[daly double]

can you record a video and share that so the sound can be heard 1st hand?

I can’t figure out how to post video...it’s a loud CLUNK almost a Banging noise...only when cold

 

[Nuke]

I can’t figure out how to post video...it’s a loud CLUNK almost a Banging noise...only when cold

Upload to YouTube and paste in a link

 

[A Guy]

Upload to Youtube, Google Drive, One Drive, etc.

A Guy

 

[daly double]

Guys....a new development here...maybe this will make sense to you guys....

The car typically sits in the driveway on an incline...pretty steep.

Last night....I parked it in the road...on a flat surface.

When I got in it this morning....and moved into gear (from Park to Reverse)....no sound what-so-ever....smooth as a whistle???

So it looks like....the sound only occurs when cold, sitting on incline....

Does that make any sense? Any ideas?

 

[trippytro]

Let the car warm up

Its totally normal to let the engine, trans, and everything else get to operating temperature. If the noise only happens when its cold, let your car idle in the cold morning until the rpm drops to 7-800

This is good practice with any vehicle

 

[BlueJesus]

I have this issue with my truck when I park on an incline. When you park in your driveway like normal, when you shift to part, before releasing the brake, engage the parking brake.
I found with my truck, when you park on an incline, it rolls back a little after it’s in park. But if you put the parking brake on before releasing the brake it won’t roll back and put tension on the transmission.

 

[daly double]

??

 

[BlueJesus]

??

Sorry if I confused you with that. Lol.
When you park in your driveway, pull in, apply parking brake, shift to park.
Then when you leave in the morning, shift to R then release parking brake.
I’m not very mechanically inclined, but this seems to be about the simplest thing you can try before looking at other things. I know it stopped it from happening in my truck.

 

[Parrott_350]

Daly Double, try this, start it in Neutral. Let the pump circulate the transmission fluid for a couple minutes before going to reverse. see if the fluid cushions that engagement. With those miles its good to get the lubrication going. Or start it in park and then put it in neutral, just just over reverse quickly.( Have foot firmly planted on the brake in case to go to Drive accidentally.) I'll just start it in neutral, easier , foot on brake. Try that see if it makes a difference.
When was the last time you changed differential fluid oil ? I can tell a difference in my D-Ram CTD when its differential fluid needs to be changed. That new oil cushions that engagement in the differential also, check it.

I always let them idle in neutral moving that transmission fluid around in my vehicles.
I think my 2016 Jeep wrangler has that transmission A5. It likes that idle in neutral, before going into drive. It makes the transition more smoothly into drive. You can tell.
Hope that helps
Best regards
parrott

 

[Rockster]

Guys....a new development here...maybe this will make sense to you guys....

The car typically sits in the driveway on an incline...pretty steep.

Last night....I parked it in the road...on a flat surface.

When I got in it this morning....and moved into gear (from Park to Reverse)....no sound what-so-ever....smooth as a whistle???

So it looks like....the sound only occurs when cold, sitting on incline....

Does that make any sense? Any ideas?

All I can offer is there has to be some play, cleareance between the crankshaft and the rear wheels. The various shafts, splines, gears and CV bearings all contribute to this.

With a manual this is often not an issue. But with an automatic since one can shift from P to R or D promptly if the car has been parked in such a way all the slack/free play is all piled up -- so to speak -- just right (or wrong) there can be a rather resounding "clunk" as the hardware moves and this slack/free play is taken up.

I avoid this with my Hellcat by pressing the brake of course and starting the engine. Then I let the engine idle long enough that idle speed slows down some. With my foot still on the brake I shift from P to R or D. Then I release the parking brake. Then I release the brake and let the car move under its own power.

No clunk.

 

[daly double]

The Parking Brake suggestion worked. I put the Parking brake on last night when I got home. No loud Clunk this morning when got in car and put it into Reverse. I guess the transmission has less "adjustments/slack" when the Parking brake is used on an inclined driveway..

 

[YouMadBro]

The Parking Brake suggestion worked. I put the Parking brake on last night when I got home. No loud Clunk this morning when got in car and put it into Reverse. I guess the transmission has less "adjustments/slack" when the Parking brake is used on an inclined driveway..

What you are hearing is the parking pawl disengaging, when parked on an incline and not using the parking brake the parking pawl is the only thing holding your car on the incline see the image below.

The entire weight of the car and depending how steep the incline is is held by the parking pawl, releasing the parking pawl while on an incline will cause a loud noise due to the amount of load on this little mechanical lever. Always a good idea to use your parking brake whenever you park your car, auto trans or not, its a good habit.

I should have been clear, the parking pawl is released by moving the shift lever from PARK to any other position.