Mechanical clunk from the rear end

[san]

Hi,

I recently purchased a 2006 ZHP ci... The car is in really good condition, but recently I noticed a mechanical clunk (not too loud) from the rear end of the car when I step on the gas pedal and also when I take my foot off the gas pedal... This happens only at very low speeds... I hear the noise only when I step on the gas... I don't hear anything when I release the clutch slightly and the car starts to move... the car 96xxx miles on it...

Did anybody have a similar issue?

Also sometimes I find it a little difficult to engage 1st gear... Could these 2 issues be related? Or could it be a clutch issue?

Thanks!

[Oli77]

Not likely to be a subframe issue with a 2006 model. Differential bushing?

[az3579]

I would say look into the following, in this order:

Differential carrier bushings (there are three total)
Center support bearing
Flex disc / guibo (goes by either name)

Do you get any vibrations at all while accelerating, or just a clunk? If just a clunk, my money's on differential bushings.

[san]

No i dont feel any vibrations... Feels pretty smooth... Just a clunk...
I think its the diff bushings as well... But shouldnt it make a sound when the car starts to move??

[az3579]

No i dont feel any vibrations... Feels pretty smooth... Just a clunk...
I think its the diff bushings as well... But shouldnt it make a sound when the car starts to move??

Not necessarily. The sound will be evident under certain circumstance, such as initial weight transfer when accelerating or lifting off the throttle. Once the weight and load has been transferred, it pretty much stays put, hence why no ongoing noise while accelerating, only on the initial application or removal of throttle.

[san]

Ok, il check it out then... Thanks....:)

What about difficulty engaging 1st gear? It feels as if im trying to push it against something rubbery when im trying to slot it in 1st gear... Only 1st gear, all other gears feel fine... only sometimes, not always....

[az3579]

Ok, il check it out then... Thanks....:)

What about difficulty engaging 1st gear? It feels as if im trying to push it against something rubbery when im trying to slot it in 1st gear... Only 1st gear, all other gears feel fine... only sometimes, not always....

Have you changed your transmission fluid recently? If so, with that oil?
Redline MTL is a very popular fluid that will make your shifting feel so much better.

[danewilson77]

Welcome. Sorry you're having problems. The guys will steer you in the proper direction for sure.

The friendliest forum on the planet!

[san]

the seller told me he had changed it just before he sold it to me... so thats close to 1500-2000 miles. Not sure of the brand of oil though... Do u think I should change it again? If not, what else could be the problem? Should the transmission oil heat up to a certain temperature for it to function properly? I only drive 2 miles to work and back...

Thanks for welcome...:)

[boilerboy95]

I had something like this on my old 2002 330CiC (non ZHP) and it seemed to occur when the car downshifted when making a turn (like into my neighborhood). Dealer diagnosis (I.e., plug it in and read codes then follow manual) said the car needed a new transmission. F-that! Online research said other items cause same codes. Moral of my story was transmission was fine, but I am curious to learn what you find because I was perplexed and didn't know what caused the clunking.

[san]

I got a ppi done before i bought it and there were no such codes (at least that's what i was told)... But it wasn't done at a dealership... But at a shop which had good reviews...

[Smilez]

Had same issue on my e36. I thought it was the guibo since it looked like it was in a bad shape. Ended up being the center drive shaft bearing that ripped from it's housing causing a lot of play during shifts. Like others have said check diff bushing too

[Vas]

Sounds like a diff clunk from the bushings.

[LivesNearCostco]

I agree most likely cause is diff bushing. But don't forget transmission and motor mounts. I had a clunk in mine when new when letting clutch out or getting on gas in 1st gear. The left motor mount had completely failed so motor was lifting up and clunking back down with hard acceleration in low gears. When my CSB failed, it wasn't a single thunk but a "whuppa whuppa whuppa" at certain RPMs as the driveshaft flopped around.

[wertyu78]

Could also be that the pinion gear bearing is on it's way out, allowing the pinion gear to "slop" around in the carrier. I have this issue with one of the backup open 3.07 diffs i have lying around.


I'd check these in the following order:

1. Diff bushings
2. Driveline slack (CSB, guibo, driveshaft, pinion slop)
3. Subframe tears



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[Tnhl1989]

It was my diff bushing

[san]

Thanks for the inputs, really appreciate it.... I'm planning to get under the car tomorrow and see if I can figure out whats wrong... Il keep you guys posted....

[BavarianZHP]

I have the same exact problem... I talked to a indy BMW mechanic and he echoed exactly what is being said here. The car is scheduled to be in on Weds for a check up and repair... What quote should we be looking at for a diff mount change? I'm holding off on alignment in case the swap or other repair could compromise it. If I don't need to hold out on getting an alignment let me know! Thanks!!!!

[BavarianZHP]

Anyone know if we can visually take a look at the bushings to see if they need to be changed?

Here's the diff mounts: I'm not exactly sure what I should be looking for but they seem ok (a tad rusted) right?

http://i218.photobucket.com/albums/cc12/Bike_enthusiast/IMAG0265_zpsbd9fa38d.jpg (http://s218.photobucket.com/user/Bike_enthusiast/media/IMAG0265_zpsbd9fa38d.jpg.html)

http://i218.photobucket.com/albums/cc12/Bike_enthusiast/IMAG0266_zpsd18742a0.jpg (http://s218.photobucket.com/user/Bike_enthusiast/media/IMAG0266_zpsd18742a0.jpg.html)

http://i218.photobucket.com/albums/cc12/Bike_enthusiast/IMAG0267_zpse4fe66c8.jpg (http://s218.photobucket.com/user/Bike_enthusiast/media/IMAG0267_zpse4fe66c8.jpg.html)

http://i218.photobucket.com/albums/cc12/Bike_enthusiast/IMAG0268_zpsb55d141c.jpg (http://s218.photobucket.com/user/Bike_enthusiast/media/IMAG0268_zpsb55d141c.jpg.html)

http://i218.photobucket.com/albums/cc12/Bike_enthusiast/IMAG0269_zps481f6c2e.jpg (http://s218.photobucket.com/user/Bike_enthusiast/media/IMAG0269_zps481f6c2e.jpg.html)

[danewilson77]

It is tough to visually tell, but those look pretty good.

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[az3579]

You've got to look closely... the smallest cracks can still cause vibrations and knocking. Mine had hairline cracks that you couldn't see from more than about a foot away but boy did the diff make a racket moving around in there even with those small tiny little cracks...

Naturally it got worse as time went on until it just became unbearable to accelerate past 1/3 throttle.

[UdubBadger]

Diff bushing for sure

[san]

So I went under the car today and found that as most of you said, it was my diff bushing...

[UdubBadger]

Mine still makes that noise even though I replaced 2/3 of them

[san]

How much would it cost to get it replaced?
Have any of you done it yourselves??

[az3579]

How much would it cost to get it replaced?
Have any of you done it yourselves??

For me it cost $300. That was a friend discount though, and labor only.


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[san]

Do you guys think I should attempt to change it on my own? I have worked on cars before but nothing specific to this....
If not, do you guys know any good shop close to Columbus, IN? Its about and hour from Indianapolis, IN... I moved to this place only 3 weeks ago so I dont know anyone here...

Also on another note, Im also planning to change the control arm bushings... Does the ZHP and a regular 330ci have the same bushings? I'm getting mixed responses on this issue.... I found these online, are these the right ones??
http://www.fcpeuro.com/products/bmw-control-arm-bushing-kit-front-e46-31126757623l

Thanks!

[mLuMaN83]

Ive got the same. It's most likely diff bushings. Thats the next thing I need to fix. No way I can handle that job myself. No lift, lack of tools, lack of time. :shift

My boss's husband is a Subaru mechanic and car nut. If I can drive to to Ocala, he might help me out. He's got the tools, the knowledge, the time, and the lift.

[BavarianZHP]

The shop just got off the phone with me... Not the diff bushings for me although I'm wishing it was.

Rear drive shaft is cracking and they want $636 for the part + 4 hrs of labor so close to $1k to fix it... I'm at work already stressed out (co-worker just quit) and can't deal with all the work he left plus this. LOL

[OtterEffect]

Holy crap. Sorry to hear that! Any idea as to what could have caused it?


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[BavarianZHP]

No idea.... The clunk has been there ever since I bought her and I've learned how to deal with it (push clutch in at certain rpm in low gear and it doesn't happen). Symptoms seem to match with the diff bushing going out although this is heartbreaking. I just spent 2k getting new wheels and tires! Good luck OP! I hope your drive shaft is better than mine. :-P

I'll ask the shop to see if they can take pics and such.

[BavarianZHP]

Called the shop for pics so I could monitor it as they won't be able to get parts until next week. mechanic told me no pics can be taken - joints/bearings/splines of drive line are difficult to see and they recommend replacing the entire part (hence the $1k). As to how it happened? Defective part is most likely (bearings/carrier joint perhaps).

[san]

sorry to hear that man...

[ELCID86]

How much would it cost to get it replaced?
Have any of you done it yourselves??

I had a quote of $500 for all 3.


Thumbs, iPhone, Tapatalk.

[san]

I need an opinion from you guys... So i still haven't changed my diff bushing yet... I need to travel about 500 miles next weekend... Is it safe to drive my car that distance without causing any damage to any other part? Or should I not drive my car till i get the diff bushing replaced?
Thanks!

[UdubBadger]

Nah you be ok

[Avetiso]

+1 you're good.

[san]

Just what I wanted to hear...:) Thanks!