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DISCUSSION => Engine + Driveline => Topic started by: E30choa on October 07, 2009, 01:57:02 PM

Title: poping noise in the rear????
Post by: E30choa on October 07, 2009, 01:57:02 PM

So ive had this noise for a week or so, if i take off slowly it doesnt happen, but as soon as i floor it, it makes a loud poping noise in the right rear end and it kind of lags on the take off???? could it be the diff, wheel, brake etc

any ideas? thanks

Title: poping noise in the rear????
Post by: roundel318 on October 07, 2009, 03:29:04 PM

diff?
that would be my best guess....

Title: poping noise in the rear????
Post by: xwill112x on October 07, 2009, 04:25:30 PM

My guess is CV joints, only they pop, your diff will let you know its going bad by making a horrible howling noise.

Title: poping noise in the rear????
Post by: bearsbmw on October 07, 2009, 05:52:20 PM

Mine is doing the same thing.... I suspect a broken offset diff bolt but I havent looked yet... does it bind up on you when you try to take a turn with some power?

Title: poping noise in the rear????
Post by: E30choa on October 07, 2009, 08:39:25 PM

well i drive my car pretty hard, and i pop clutch pretty much daily:D and really didnt think it was my diff cause i heard it from the right rear end not the middle, there is also no howling noise. so how do i check if its the cv joint?

(bearsbmw)well pretty much anytime i try to accelerate to quick it pops, so yeah i hope we both get this fixed

Title: poping noise in the rear????
Post by: nicknikolovski on October 08, 2009, 03:10:43 AM

Wear in the inner joint of the half shaft shows up as a "clunk" or "pop" when applying power, or if severe, when lifting off the throttle. If you claim that you can hear it from the RHR side, replace the RH shaft.

What I would do is jack the rear of the vehicle, under the diff is fine but place axle stands on the rear jacking points as well. Then have an assistant get in vehicle and try to acclerate in first gear as normal. You will see the rear wheels rotating, at the same time you can listen for the noise and observe for anything that doesn't appear to be correct. (Please remember the dangers involved in doing this. Choke the front wheels and make sure your stands are 100% firmly supporting the vehicle)
Grab hold of the actual half shaft (RH), and try moving it in and out, up & down. You will see if there is excessive play in either the inner or outer joint.

Title: poping noise in the rear????
Post by: E30choa on October 12, 2009, 01:20:32 AM

so your saying i should replace the whole right shaft assembly cause i was thinking maybe the right shaft support, the one with the bearings:confused:
kinda new at this

Title: poping noise in the rear????
Post by: nicknikolovski on October 12, 2009, 03:40:04 AM

You've kind of lost me when you say the right shaft support with the bearings? Have you got a photo and did you check the CV joints?

Title: poping noise in the rear????
Post by: E30choa on October 12, 2009, 11:29:35 PM

http://www.pelicanparts.com/cgi-bin/ksearch/PEL_search.cgi?command=show_part_page&please_wait=N&make=BMW&model=BE30§ion=TRANSM&page=3&bookmark=10&part_number=26-12-1-225-152-M36 (http://www.pelicanparts.com/cgi-bin/ksearch/PEL_search.cgi?command=show_part_page&please_wait=N&make=BMW&model=BE30§ion=TRANSM&page=3&bookmark=10&part_number=26-12-1-225-152-M36) i was thinking maybe this, and i grabed and nuged it with my hand but seems fine:confused:

Title: poping noise in the rear????
Post by: nicknikolovski on October 13, 2009, 06:34:29 AM

I was saying this
http://www.realoem.com/bmw/showparts.do?model=BE52&mospid=47425&btnr=33_0468&hg=33&fg=25

2 shafts sit on both sides of the diff and go through the rear hub assemblies.
Check the joints on part no. 1. The joints themselves are hidden behind the rubber boots. If the joints have failed, you can get the shaft re-conditioned or replace it with a S/H or brand new complete shaft.

Title: poping noise in the rear????
Post by: waldo on October 19, 2009, 08:59:34 PM

Most auto parts chains can get re-man half shafts in a few days.  Cost is typically less than 100 per.  I have replaced both of mine as my boots were torn and the shafts were just a little more than boot kits..  Patience and a big hammer is needed to install.

However, CV joints will have a ground speed tick as the axle rotates and the joint moves.  Sounds more like you might have lash in your diff gears.  Does it also make the sound when you abruptly lift?

Title: poping noise in the rear????
Post by: bearsbmw on October 20, 2009, 12:00:12 AM

Mine turned out to be a blown diff along with bad bearings inside the diff houseing and the gears were binding on the houseing barely staying intact

Title: poping noise in the rear????
Post by: DesktopDave on October 20, 2009, 09:18:10 AM

I had some issues with my diff too.  It would grind, growl & bang away.  Shot input shaft bearings.  I could move the input flange about an inch with my bare hands!

If you're nailing the clutch on every start you'll be replacing a lot of parts down the road...you might want to think about installing a medium case diff.  A lot of different BMW diffs fit in our cars.  I'm running a medium case 3.73LSD from an '87 325is...it's much heavier and I'd suspect stronger too.

Title: poping noise in the rear????
Post by: bearsbmw on October 20, 2009, 10:24:56 AM

Quote from: DesktopDave;80170

I had some issues with my diff too.  It would grind, growl & bang away.  Shot input shaft bearings.  I could move the input flange about an inch with my bare hands!

If you're nailing the clutch on every start you'll be replacing a lot of parts down the road...you might want to think about installing a medium case diff.  A lot of different BMW diffs fit in our cars.  I'm running a medium case 3.73LSD from an '87 325is...it's much heavier and I'd suspect stronger too.

I agree! I'm surprized I got as much out of my diff  as I did seeing how im pushing 17psi  and running our local QT mile track every weeknd for the whole summer