E46 auto 'thud' noise from rear? 1st to 2nd.

[herco]

Hi gents!

I am planning on taking ownership of my dad's '05 320d. 255k on the clock and going strong.

However, when accelerating slowly the car makes a 'thud', almost grinding noise from the passenger rear when shifting from 1st to 2d. It never happens on downshifts, and under rarely under moderate acceleration. 

Most often when slowly accelerating after a speedbump or cruising in a parking lot.

I doubt it's the transmission, as a lot of work was done on the tranny recently and all other shifts are silky smooth.

Guessing it's diff or prop related? I'm nervous a thud becomes a THUD.

 

[Camnefdt]

check diff bushes, my 320i did exactly the same when i bought it.

 

[Nikhil]

1) Engine mounts

2) Rear diff bush

Both those items will be shot at that mileage if never replaced and both give you the above symptoms mentioned.

 

[herco]

1) Engine mounts

2) Rear diff bush

Both those items will be shot at that mileage if never replaced and both give you the above symptoms mentioned.

Thanks Nikhil and @"Camnefdt".

I think engine mounts is a good place to start, as the car feels abnormally shaky at idle.

I will have them both replaced at the same time.

 

[Tinuva]

1) Engine mounts

2) Rear diff bush

Both those items will be shot at that mileage if never replaced and both give you the above symptoms mentioned.

OP, this is the answer!

The rear diff bush is definitely gone. Probably needs replacement every 100k km.

The engine mounts, is what I also need to look at next.

 

[herco]

1) Engine mounts

2) Rear diff bush

Both those items will be shot at that mileage if never replaced and both give you the above symptoms mentioned.

OP, this is the answer!

The rear diff bush is definitely gone. Probably needs replacement every 100k km.

The engine mounts, is what I also need to look at next.

Yeah, everything I get my hands on points to diff bushes.

Any idea at the cost involved to replace these?

 

[Tinuva]

1) Engine mounts

2) Rear diff bush

Both those items will be shot at that mileage if never replaced and both give you the above symptoms mentioned.

OP, this is the answer!

The rear diff bush is definitely gone. Probably needs replacement every 100k km.

The engine mounts, is what I also need to look at next.

Yeah, everything I get my hands on points to diff bushes.

Any idea at the cost involved to replace these?

This was a quote on Jan 2020.

Sent from my Mi 9T using Tapatalk

 

[herco]

This was a quote on Jan 2020.

Sent from my Mi 9T using Tapatalk

Did you go for the poly or the original from agents?

 

[Tinuva]

This was a quote on Jan 2020.

Sent from my Mi 9T using Tapatalk

Did you go for the poly or the original from agents?

Poly. At this point, I am not sure if it will last longer than the oem.

They fail different. OEM rubber breaks apart. Poly becomes rock hard from what I understand, so it also needs to be replaced eventually.

 

[Nikhil]

I went with OEM eventually which has lasted the longest, did Meyle, teknorot and Febi and they all failed very quickly

 

[Tinuva]

I went with OEM eventually which has lasted the longest, did Meyle, teknorot and Febi and they all failed very quickly

How quickly if I may ask?

Currently on Powerflex purple (normal road driving version). They also do Powerflex black for racing which I decided is not what I want.

 

[Captain_Stealth]

definitely diff bushes but I would also check the propshaft center bearing and propshaft guibo aka donuts

 

[Nikhil]

I went with OEM eventually which has lasted the longest, did Meyle, teknorot and Febi and they all failed very quickly

How quickly if I may ask?

Currently on Powerflex purple (normal road driving version). They also do Powerflex black for racing which I decided is not what I want.

20k km approximately on the Meyle and teknorot, febi was about 40k km ish. OEM has been on for 80k km now no issues

 

[Tinuva]

I went with OEM eventually which has lasted the longest, did Meyle, teknorot and Febi and they all failed very quickly

How quickly if I may ask?

Currently on Powerflex purple (normal road driving version). They also do Powerflex black for racing which I decided is not what I want.

20k km approximately on the Meyle and teknorot, febi was about 40k km ish. OEM has been on for 80k km now no issues

Oh wow thank you. Expected a bit more from Meyle but I guess it is what it is.

The OEM I expect to last at least around 100k if not a bit more. I will see how long this powerflex last, but I do like the slightly softer feel of the OEM a bit more. Its actually worth it.

 

[KPM3_30]

@"Tinuva" Meyle quality has gone to shit in recent years with them manufacturing parts out of China.. I know of so many cases where Meyle parts have failed soon after fitment. 

I chose to rather buy parts from the agents where I could only find Meyle. If not Meyle HD, don't bother.