Advice please - strut tower cracks

[m3f_TheDukeGTi]

Hi all, I'm looking for some advice regarding my E36 M3 ('96).



Firstly [DISCLAIMER], I appreciate that the severity of issues will be difficult to ascertain through images posted, but any input would be greatly appreciated.



I found some (minor?) cracking at the top of my rear shock tower on the drivers side. The cracking doesn't look too severe at this point, but of course, I want this to be fixed and further cracking to be prevented. I would like to know what I can get away with here.



The garage I took it too said they would need to cut out and replace the tower. The amount of cracking would suggest to me that this is a bit drastic. My thought was that the cracks could be welded (if even that is required?) and I could add a strut bar or reinforcement plates.



Some details to aid a decision:

- WILL be used on the street, and hopefully some track days/autocrosses.

- WILL (may) have the springs and shocks upgraded to Bilstein/H&R, or whatever is best, at a 'sport' level.

- WILL have top-mounts replaced at the same time as they are worn.



- WILL NOT be put on race springs

- WILL NOT be put on coilovers

- WILL NOT be competively drifted or raced, but may be driven hard very occasionally.



- Undecided about upgrading bushings, maybe polybush, maybe uprated, maybe OEM. But not anytime soon.

- Safety and longevity are my main priorities. The car should also continue to handle like a standard M3.

- The roads around the bay area are not the best.



So folks, what's the best resolution here? How bad is it? How far do I need to go with this fix?



LEFT:

Towards rear:







Towards front:







RIGHT(looks good to me):











Thanks for your input folks!

[m3f_97_4dr_5spd_m3]

Very common problem. I had one punch completely through.



I would take off the struts, inspect the metal/see how bad the cracks are, and if you feel that they are only surface, buy the plates off of the link or from any other aftermarket BMW supplier.



Most places carry them as "strut tower reinforcement plates."



https://www.ecstuning.com/ES2642687/...2icaAlph8P8HAQ

[m3f_Olemiss540]

+1. Should be able to weld the cracks if needed. Put new RSMs and the factory reinforcement plates on ASAP

[m3f_Laxbmw17]

Had to have one replaced this past summer. I decided to have the shock tower cut out and and new one welded in. Better to not do just bare minimum with an e36, it will come back to haunt you, especially seeing how you said the car will be on a track at some point. Also added the full reinforcement kit from turner to prevent any other common failure with the e36.

[m3f_Oogie_M]

Mine had cracks around the rim opening where the strut feeds through. My shop builds BMW race cars and they recommended reinforcement plates instead of replacing the entire shock tower (the original quote was to replace the entire shock tower + reinforcement plates). The BMW epoxy and etching was applied and then repainted to look factory new. Picture below shows the prep work before paint.

[m3f_fiveightandten]

Have the cracks welded, re-coat, then put new mounts on there with reinforcement plates. You can have reinforcement plates welded to the top as well. The plates should have been on there in the first place.


Worn shock mounts and/or worn shocks is what causes this. They don't really crack on stock suspension in good working order. It doesn't matter what springs you run back there unless they're bottoming the shocks out. How you drive the car isn't really a factor, but the type of roads you drive on can be. The type of shock will matter a bit, and the type of mount will matter a bit. But the most important thing is getting it fixed and reinforced before it gets any worse, and getting new components in there.


Again, if the shocks are worn, they're contributing to the problem. Worn shocks bottom out too easily and slam into the bump stops with a lot of force. That slams away at the mount and tower pretty hard. Obviously this can happen from running lowering springs that are bottoming the shocks out, as well.

[m3f_bhennrich]

Have the cracks welded, re-coat, then put new mounts on there with reinforcement plates. You can have reinforcement plates welded to the top as well. The plates should have been on there in the first place.



Worn shock mounts and/or worn shocks is what causes this. They don't really crack on stock suspension in good working order. It doesn't matter what springs you run back there unless they're bottoming the shocks out. How you drive the car isn't really a factor, but the type of roads you drive on can be. The type of shock will matter a bit, and the type of mount will matter a bit. But the most important thing is getting it fixed and reinforced before it gets any worse, and getting new components in there.



Again, if the shocks are worn, they're contributing to the problem. Worn shocks bottom out too easily and slam into the bump stops with a lot of force. That slams away at the mount and tower pretty hard. Obviously this can happen from running lowering springs that are bottoming the shocks out, as well.

[m3f_TheDukeGTi]

Thanks for the help folks. Really gives some good perspectives.