Rear Shock Tower Catastrophic Failure (Pics Attached)

[ManManinc]

ahhhhh I'm having flashbacks!

[ELIBEEMER]

ouch! Im curious how it happened?

did you hit a Speed Bump/Driveway/pothole at high speed

Edit: this happened to my 1st E36, was not a FUN fix. I need some Reinforcement Plates for my E31!

[8eights]

..... If you don't put the plates in place, It will happen regardless of road conditions, This part of the car is just poorly made.

[ManManinc]

yea, when i heard the snap back there, I was pulling out of my driveway

[Koizumi]

Takes 5 easy minutes to install the plates, so what are y'all waiting for folks!

PS: OP: sorry to hear/see the crappy news

[850ciTHompson]

Here is the email for ordering the plates:

gspeechley@phoenixmotorsport.co.uk

Have your Pal Pal account ready...about $71.00 (46 GPB)

[mjrgroup]

ouch! Im curious how it happened?

did you hit a Speed Bump/Driveway/pothole at high speed

Edit: this happened to my 1st E36, was not a FUN fix. I need some Reinforcement Plates for my E31!

It may have happened when I had my "accident" (check my other really long thread), but I have had a rattling noise for a while but did not suspect this was the cause. And whenever I looked under the car it looked fine (not the way it looks now)...so I think recently it fully separated while before it was "hanging on by a thread."


BTW: I just ordered shock tower reinforcement plates from Pheonix and will be using them in addition to welding BOTH left and right supports from BMW. I'm going to have the strongest rear shock towers out of all of you.

[GreatWhiteNorth]

Just ordered mine from Gerry. Hope there is no damage when I go to install them.
Sorry to hear about/see the bad news mjrgroup.
Thanks to everyone else for the great feedback.
Cheers

[sjflat]

I wonder how Gerry's sales have increased since this thread!? I for one have just ordered some reinforcement plates.... been meaning to get on it for a while and this thread has served as a gentle reminder!

[Major Cheese]

Is the CSi prone to the same weakness? And if so, do these plates fit as well or will they need modification?

Thanks, Brian

[luv8]

Just ordered mine from Gerry. Hope there is no damage when I go to install them.
Sorry to hear about/see the bad news mjrgroup.
Thanks to everyone else for the great feedback.
Cheers

I got mine 3 months ago and been sitting on them. A picture tells a thousand words! Randy has rear shocks for me, so looks like a trip back to NJ for beers and wrencing is coming soon.

[Cadillacwill]

how do you install the plates, and how can I tell if I already have them. I have a feeling one of the PO's might of installed the plates.

[Major Cheese]

Here is the email for ordering the plates:

gspeechley@phoenixmotorsport.co.uk

Have your Pal Pal account ready...about $71.00 (46 GPB)

I just ordered mine for $65 including shipping.

[spillmk1]

I wonder how Gerry's sales have increased since this thread!? I for one have just ordered some reinforcement plates.... been meaning to get on it for a while and this thread has served as a gentle reminder!

I dare say Phoenix Motorsports stock has gone up quite a bit today!!!

[8eights]

I doubt it, Most veterans were on top of the plates years ago when most people here were posting on Roadfly. I'm sure all the new oweners did'nt know about them though. They're great insurance and you can diy!

[Koizumi]

I posted a 'how to install' thread about installing H&R fronts + custom rear springs a long while back, with pics of the plates install. The search for "lowered drop" by yours truly. It takes 5 minutes to install them. Use Loctite please!

[850ciTHompson]

I emailed Max after I placed my order too, asked if he was a bit busy... Max's reply...

" Yeah, I noticed. A little FUD goes a long way, lot of plates going out. I've had both the factory and Gerry's plates on hand for a couple years, just in case. Yours will be in the mail today."

[Imndeep]

Here's a picture of my passenger side rear shock tower support. It's hard getting a camera back there so this is the best shot I got. It's the black piece on top of the tower. Not too happy about grip length on the nuts but oh well.

[Arlington8]

The "rip" is caused by 2 things: sport springs /lowered suspension and large diameter wheels and tires that offer very little sidewall "bounce"...

And even if you don't do any of that, still do the modification.

When I got my eight, this was one of the first things I did.

Easy and quick.

Anyone out there that has not done so should. Simple as that.

Standard prudence.

[wokke]

I did the repair several months ago on a customer's car which had not yet failed, but would you like your car's rear suspension be mounted to something like this?



I purchase the above mentioned original spare from the stealer (amazingly cheap BTW) and welded it into place. I've done welding jobs before so it was not a learning experience

[8Tech]

Is the CSi prone to the same weakness? And if so, do these plates fit as well or will they need modification?

Thanks, Brian

The CSi is even more prone to this failure because of the stiffer rear dampers. The plates fit all models of E31 without modification. Fit Bilstein or other uprated dampers, or even new stock dampers without these plates at your peril, it's only a matter of time before the failure for a job that takes about 20 minutes.

8Tech.

[8eights]

Here's a picture of my passenger side rear shock tower support. It's hard getting a camera back there so this is the best shot I got. It's the black piece on top of the tower. Not too happy about grip length on the nuts but oh well.

All to true about grip strength deep, That's why i countersinked the holes on the plates, I got double the thread bite, Good post!

[IvanHansen]

Just ordered some plates from Gerry as well - better safe than sorry

[sjflat]

I set about fitting the reinforcement plates earlier and somehow managed to snap a bolt. I read elsewhere that they should be tightened to 25Nm but I still managed to shear one of the bolts. I'm not sure why this could be... perhaps I was wrong to assume it should be 25Nm or maybe the incorrect bolt was fitted (I know that the rear shocks have previously been replaced).

I have temporarily abandoned work until I can get a new bolt: looking at it, it would appear I can just take the wheel off and get at it from underneath (is that correct?).

Since I need to get one new bolt I wondered if it may be worth going for something a little stronger/longer. Does anyone have any suggestions? Perhaps Gerry may have some (I'll drop him an email if he doesn't respond on here though).

My mishap aside, this really is an easy job and everyone should deffinately get these fitted or be prepared to face the consequences.

Steve

[mjrgroup]

Rear Shock Mounting Bolt (Part, size and length)

I was just under my car as well and removed the nuts from the top of the shock tower. The bolts seem stuck on the shock tower mount and are not free-floating (at least not on mine). So it might be easier to just remove the shock entirely and then replace the necessary components.



Part #10 are the two bolts which mount the shock tower to the chassis, it is BMW part #31336765744 (M8X18 ZNS3). If you want a longer bolt, you'll need an M8 bolt x [length]mm.

For me, the width of the BMW Support Plate AND the Reinforcement plate combined is 8MM!

I got 3/4 of the parts I need: both reinforcement plates from Max and the driver's side BMW support. I'm still waiting on the passenger's side BMW support (the one I need)!
But with the supports and reinforcement plates, I'm definitely going to replace the bolts and nuts with longer ones. Plus, on a 20 year old car I wouldn't feel secure reusing an old bolt in such a high stress location.

I'll take some pics and post them to this post in about an hour.

EDIT: Pictures attached below:

Driver's Side BMW Support Plate (Support for Shock Absorber LEFT {Driver's side; BMW Part #: 41148152997})
This is a close-up of the BMW Support Plate for the driver's side rear shock tower mount point. This plate is to-be welded to the outside of the chassis at the highest point of the wheel well. It provides a 3mm thick steel mounting point for the shock.


Reinforcement Plate (Left/Right Interchangeable)
Phoenix Motorsport Aftermarket Rear Shock Tower Reinforcement Plate. This image shows one of two plates required per car for the upgrade. The plate is placed atop the shock tower mount and distributes the pressure at the two bolting points.



Reinforcement Plate atop Support Plate
This image shows the Phoenix Motorsport Reinforcement Plate resting on top of the BMW Support Plate, for even stronger rigidity of the overall mount and greater load dispersion of the rear shock tower mount points.

The width of the BMW Support Plate (3mm) & Phoenix Reinforcement Plate (5mm) combined is 8mm thick!