I have this same problem. 2016 GLA 45 AMG with 40k miles.

When I come to a stop, or almost come to a stop, the car will make this deep thud sound "as if" the gas tank was loose and was hitting something. Having owned a GTR with DCT, I knew these transmissions are not the smoothest nor the quietest, so I assumed it was just normal operating quirks and noises.

Although the car has had all its scheduled maintenance, I'm thinking that if you don't ask for this software upgrade, it will not get done. So I will probably bring it to MB in Colorado Springs and see what they say.

Thank you for the comments and recommendation provided above.

 

I have this same problem. 2016 GLA 45 AMG with 40k miles.

When I come to a stop, or almost come to a stop, the car will make this deep thud sound "as if" the gas tank was loose and was hitting something. Having owned a GTR with DCT, I knew these transmissions are not the smoothest nor the quietest, so I assumed it was just normal operating quirks and noises.

Although the car has had all its scheduled maintenance, I'm thinking that if you don't ask for this software upgrade, it will not get done. So I will probably bring it to MB in Colorado Springs and see what they say.

Thank you for the comments and recommendation provided above.

I had the same problem. Ended up being the PTO in the transmission starting to fail. It transmits the rough engagement sound thru the driveshaft to the differential. That's why you hear it from the back. Check the breather on the differential. I believe the manager said the clogged breather can create a similar problem as well.

 

So glad to see folks posting about this problem in the past few days versus 2015.... I have a 2018 GLA250 4 matic and the back end noise is awful. Sounds like bass booming in a bad song at times, especially when I turn slowly and hard right into my driveway. When coming to a complete stop the majority of the time, I hear and can feel a "thud" from the trunk area. I drove to the dealership a few weeks ago (45 minute drive) and of course the sounds would not duplicate with the mechanic in the car. I was told they would attempt to duplicate it on a "cold start" the next day but when they attempted it, of course they heard nothing....
Did you get resolution for the problem?

 

Hey everyone I had the same thing happen on my 2015 gla250 4matic. After 3 different diagnostics done the and the final done by Mercedes. All 3 came to the same issue which is the rear differential needs to be replaced. Which totally sucks because it’s not cheap. Also what is sucks even more is Mercedes’ knows of this problem but only put out a TSB on this problem and not a recall. I don’t understand if so many of these cars are having the same issue why they won’t just recall it. But long story short I am now having it replaced at the fine price of $5600.00!!!! …….ummm yea, you heard correct that is how much it is costing me. So I pray I never have to have it replaced again. So if you are having the same problem have that checked out! I’ll update you all once I pick up my car from Mercedes’

 

This is because the car has a dual clutch gearbox which is known as a transverse gearbox which switches from two wheel drive to four-wheel-drive so it’s just the characteristics of the car with it engaging the diff from two wheel drive to four-wheel-drive it’s normal in a lot of AMG 45 or 63 is or even any of the 4 matic hopefully this is useful information as I had so many garages look at my GL a 45 and they couldn’t find anything wrong with it it is just the characteristics of the car even on YouTube there are car viewers that say the same thing but you have to get used to it

 

I have a GLA 220 2014 and 55000 miles.

i have a knocking noise only if I am at speed of 0-25mph, in drive mode

Both if I accelerate and if i don't accelerate or IF I break.

the noise increases in frequency if I turn right or left.

no knocking noise in neutral and rear.


do you think is the differential?
thanks in advance to everyone!

 

Hi there i got same problem.do you know what happen it is? Please

 

Welcome. Lots of replies outlining the cause in this thread. It's either a transmission issue or rear differential, the latter of which only applies to 4MATIC models.

 

I brought my '15 in for the clunk and the occasional reverse grind in the cold (under a 6-month 3rd party warranty after purchasing used from a Mercedes dealership). They replaced the diff, after which they now say the trans is making odd noises. So it looks like they're going to try and replace the trans too.

Yikes, that's in the $12-15k neighborhood for the warranty company. Over half of what I paid of the car!

 

I brought my '15 in for the clunk and the occasional reverse grind in the cold (under a 6-month 3rd party warranty after purchasing used from a Mercedes dealership). They replaced the diff, after which they now say the trans is making odd noises. So it looks like they're going to try and replace the trans too.

Yikes, that's in the $12-15k neighborhood for the warranty company. Over half of what I paid of the car!

Yikes... at least it's not on your dime. I'm not sold on the DCT for the GLA anymore given that it doesn't seem well-suited for it. It's marketed as a city car in a way, but it's not great in stop-and-go traffic and is lurch-y at low speeds or when it's cold. There must be significant clutch wear in these situations. It's nice and quick on the highway and cruising speeds, but that doesn't happen much in town.

I've driven other DCT cars in the past with the same issues, except they have mainly been performance cars. I know there was a fad of putting DCTs in a lot of cars some years ago, but it seems that most companies have returned to CVTs or TC autos in following years, even performance cars (F80 M3 had a 7DCT, G80 has an 8-speed auto). Performance automatics are also now very fast but offer far more comfort and daily drive usability. The 9-speed auto in the GLE53 is as quick or quicker than the 7DCT in the GLA250. Not a totally fair comparison, but my point stands.

 

I possess a GLA250 4-matic and have encountered persistent issues similar to those outlined here. Today, I brought it to the Mercedes-Benz service center, where they informed me that the likely culprit is the rear differential, and the repair will cost approximately $4000. My car has only traveled 85,000 kilometers and unfortunately, its warranty has recently expired. It's disheartening to realize that despite the premium ownership price, Mercedes-Benz isn't proving to be any better than an average car.

 

If you have the means.. try going under your car and grabbing the shafts that come out of the diff, there’s one on each side of it. If one or both has excessive play/can be easily moved by hand then a diff bearing is probably wearing. Someone stripped a diff from a CLA45 on the CLA forums and found ‘Made in China’ stamped on the worn bearing FWIW…

 

I have a 2015 GLA 250 with 114k miles on it. Lately there has been a "clunk" noise coming from the rear. I had the diff oil changed and it did not help. My mechanic tested it with and without the rear solenoid attached and confirmed that the differential needs to be replaced. He tested it in 2WD only and it runs just fine with no noise. Soooo................ We are thinking of just leaving it in 2WD for the time being and skipping the whole repair. we'll sort of evaluate how it goes day to day. Does anyone have an opinion on this? My mechanic doesn't see anything wrong with this, it just won't ever go into 4WD. we live in a mild climate so not really worried about snow, front wheel drive is usually all we ever need.

 

Hello I have a 2024 GLA 4matic that I bought in Jan and I have driven only 250 miles primarily on inside roads - I’ve noticed the clunk and shift noise while braking too or coming to a stop, sometimes when I park or when I start the car from a stop. It’s annoying to continually hear the clunking or shifting noise. I also find it extremely noisy when moving from D1 to D6. Does anyone here have similar experience with a 2024 car ?

 

Obviously on a brand new vehicle you're well within warranty so take it to dealership service and have them do a test drive and analysis. They may have missed something in delivery-prep, such as shipping blocks (suspension related but not transmission). Or perhaps the factory didn't properly fill the transmission/differential fluid. Again, take it to service.

This thread commenced in 2015 so some very good general insight but perhaps not specific to your 2024 situation. Not sure why you posted to a thread in the first generation 2014-2019 section and not the 2020+, as the latter is a quite different 2nd generation.

 

I have heard the same noise in my GLA 250 2024. I’ve only had it two months, and it has just over 1000 miles on it. Have you found out anything more?

 

My new 2025 gla250 clunks in rear cabin during shifting. Is there an update needed?

 

Servus hoffe mal das Thema ist noch aktuell. Habe zwecks des Klopfens mein Auto jetzt ein neues Heckachsdifferenzial verpassen lassen. Klopfen ist immernoch da lediglich wenn ich selbst runterschalte ist es weg.

 

Hallo hoffe das Thema ist noch aktuell, habe zwecks des Klopfens meinen Gla jetzt ein neues Heckachsdifferenzial verpasst. Klopfen ist immernoch da lediglich wenn ich selber Schalte ist es weg.