Broke bolt in Rear End

[squartus]

Well after thinking I wasn't going to make it back yesterday after car started making ton of noise in rear and handling rather umm oddly lol I backed it up onto some ramps and what do I find.



Well no wonder! All the noise was it hitting my exhaust and my car was really low on left side and of course car driving like was about to fall apart was explained.




Sheared off bolt was the reason it seems, now question is.. is this a symptom of something else or is this just one of those things that happen if a nut works it way loose?

[JEllis]

Not uncommon for 6spds. I am upgrading my diff bushings to aluminum/delrin to avoid this issue. Turner sells them.

[SHADY1]

Originally Posted by JEllis

Not uncommon for 6spds. I am upgrading my diff bushings to aluminum/delrin to avoid this issue. Turner sells them.

The same bushing I have installed on my M3


http://www.turnermotorsport.com/p-29...um-e9x-m3.aspx

You can see pics and install of my bushing in this thread:

http://www.m3post.com/forums/showthr...=843389&page=4

[dvpouldar26]

The same thing happened to my friends car. Fairly common on 6spd's. That bolt can't handle much abuse from hard launches and the weight transfer from aggressive shifting.

[CSL_E36]

Was anything done specifically to instigate this problem? Burn outs? Track time? Drifting?

[FogCityM3]

Same thing happened to me..I have a 6 MT and I have not abused my car whatsoever. BMW NA agreed and covered fully under warranty. I honestly think it is a design flaw (rubber bushing, not mounted solidly, and 3 bolts instead of 4) that was subsequently corrected in M3 GTS, M3 CRT and F10 M5/6 and F80 M3/4.

[squartus]

I drive my car fairly aggressive but no track time, no driving that this car isn't made for that's for sure.
Shouldn't of broke.

[JEllis]

Upgrade your bushings and that will prevent the problem in the future.

[Stronie]

I've seen this a few times, seems like a trend.

[gatorfast]

Any damage done? Is it as simple as replacing the bushings if the bolt fails?

[pbonsalb]

Broken diff bolts are common on E36M3 from hard launches. Stiffer bushings and/or a diff support brace help. On the E36M3, it is the front diff bolt that goes. The two rear ear bolts are not a problem. I'll probably do poly subframe mounts and diff mounts on my E90M3 like I have done on my E36M3.

[ThatGuyMikee]

I filled my stock bushings with silicone , yes silicone, packed it in, let dry for a
Day and becomes a solid bushing with no movement, sounds stupid but it works fine , alot of nissan and other guys do it

[JEllis]

Originally Posted by Stronie

I've seen this a few times, seems like a trend.

Certainly not uncommon, also not a big deal.

Originally Posted by gatorfast

Any damage done? Is it as simple as replacing the bushings if the bolt fails?

Unless you drive on it your not going to cause any damage. You can simply replace the bolt if the bushing is still good (not a good idea though). The bolt fails due to the bushing failing to adequately stabilize it. Solid bushings and a new bolt will probably last the life of the car.

[e92zero]

but solid bushing adds a lot of noise/vibration. I wish there is a 'quieter' solution that won't add the drive train wine. Someone mention above that the GTS and the CRT has a 4 point mount system for the rear diff. Anyone can confirm that or have picture?

[Someone?]

Wouldn't these bushings be better then the solid ones, with less vibration?http://www.turnermotorsport.com/p-14...1m-e9x-m3.aspx

[squartus]

No damage done like has happened to some "bent subframe or torn brake line" just pain in my ass since this is my DD.

Still looking into new mounts to replace these factory ones with, which is sad since my car only just now hit 20K miles.
Lot of reports of excessive noise with the solid metal mounts even over aftermarket exhausts.

[Someone?]

Click my link in prior post, seems like a better alternative to solid mounts, well they are still solid kinda.

[squartus]

Thanks Mike, that was the one I was leaning towards. While im at it I may as well replace all the bushings in the rear end, seems makes a huge difference in handling.
Also ordered new trans mounts

[urbinoxgng]

The same thing happened to my friends car.

[ThatGuyMikee]

Originally Posted by e92zero

but solid bushing adds a lot of noise/vibration. I wish there is a 'quieter' solution that won't add the drive train wine. Someone mention above that the GTS and the CRT has a 4 point mount system for the rear diff. Anyone can confirm that or have picture?

Silicone

[JEllis]

Originally Posted by e92zero

but solid bushing adds a lot of noise/vibration. I wish there is a 'quieter' solution that won't add the drive train wine. Someone mention above that the GTS and the CRT has a 4 point mount system for the rear diff. Anyone can confirm that or have picture?

The GTS and all new M cars (M5/6) have solid subframe mounts. I am not sure if this is the case with the diff bushings or not.

The added vibrations caused by solid bushings is subjective. I have heard of people not even noticing a change.

[SflBimmer8484]

We have replaced 4 bolts already.