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Discussion Starter · #1 ·
Have owned car since 2008 81k miles. No track days. No smoky burnouts. No donuts. This happened turning from one residential street to another. Probably 10-15mph. In talks with Clemster about a reinforced used unit, but my mechanic "has a guy" that welds aluminum. He's going to have him come take a look at it first. Curious...has anyone here successfully repaired one of these once it's failed?
This took out the rear 1/2 of the driveshaft even at that low speed. I'll keep you guys posted.







 

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Discussion Starter · #3 ·
I would use a different subframe. That is a severe failure!

--Peter

Are you implying other people have suffered nice failures on this part? :smile
 

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Welder-Smelder. A little JB weld epoxy and you'll be golden. :grin

FWIW, unless the material is so twisted you can't re-establish the correct position of the bushing, there really is no reason that one couldn't be welded up and reinforced. It would be easier and quicker to start with one that isn't broken and add the reinforcement plates to box that one in.
 

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Discussion Starter · #6 ·
Curious, have you ever jacked up the rear using the diff?
Negative, but I like that you thought of that. I didn't.
 

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Can't reuse that, especially with aluminum. If you weld and reinforce that, it's prone to breaking again.

Definitely start with a new/used one and reinforce that. I really think these things crack due to age and not driving style. I've seen original ones in fine condition on abused cars and broken ones on cars that see 3,000miles per year. So I think it's a age/weather thing
 

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I had the same thing happen about 2 months ago. Similarly, I just also moved off from a stoplight and was going ~10 mph when I heard a bang followed by the sound of the driveshaft rubbing against the tunnel. The car had 124K miles and subframe & diff bushings were in ok shape at the time but the rear wishbones were shot (boots were damaged). I ended up going with a reinforced unit from Clemster and as a few people have mentioned already, I would recommend that option rather than repairing and reinforcing an already damage subframe.
 

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I reinforced mine in-car. Just dropped the diff, built a plate for the mount, and had a welder buddy go at it. So for those wondering, you don't need to drop the entire subframe and disassemble it if the guy welding is good enough with overhead positions.
 

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Discussion Starter · #15 ·
Humm that's really strange then, I assume no impact damage either.

Well even at that low speed the back 1/2 of the driveshaft did contact the exhaust (or something) and is a goner accd. to my guy.
 

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Discussion Starter · #16 ·
What was the condition of the subframe bushings?

Unknown. The whole assembly was in front of me when I took those pics, but I didn't think to check any bushings. I can/will if they haven't replaced them with my new parts already.
 

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Discussion Starter · #17 ·
And independently of you guys I've been growing more wary of a repair vs. a Clemster unit. For all I know my guys aluminum guy is looking at it right now saying "no effin' way." That reminds me I need to call them and see if this dude has stopped by yet. I almost hope he rejects the work, but even if he doesn't I think I may pull the plug on it. The problem w/ this break is that it takes out other parts along with it. Combine that with the labor and doing this once is a fair bit of loot. 2x is absurb plus the risk of the high speed failure.
I think I'm rating the fear of this breaking right next to the rod bearing paranoia we all have. ;)
 

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Discussion Starter · #18 ·
Hmmm...well I just called my shop. I spoke to the owners wife Friday around this same time of day and she told me the aluminum guy hadn't come yet and wouldn't until "early next week." Well I'm calling them 2:30pm EST today (they're closed all weekend) and somehow between then and now my subframe went out to his guy and has already been repaired and returned. Man talk about a day late and $1 short. So I guess I get to be the 1st mofo here that's used a repaired subframe. Wish my a** luck! I think I need it. I'm going over to look at it in the a.m. I'll snap some pics. Will bring the iPad Air this time so the pics don't suck.


Anyhoo, my guy is very confident that this will never fail again. He spoke quite highly of his welder and said flat out if the guy had any reservations at all he would have rejected the job. He has been working with the guy forever and he has in fact called items unfixable before. Apparently welding aluminum is this gents full-time job not a hobby. He did say that the guy forced them to strip everything off the frame so that he could dip it. I assume the dipping is to remove all contamination/oxidation prior to being worked on. There's also two reinforcing plates on there now front and back. I sure hope the repair itself looks as good as it sounded so far over the phone. If not I'll be the fella that learns the hard lesson for y'all.


Thanks so far fellas. All input greatly appreciated.
 

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Discussion Starter · #19 · (Edited)
Man they're quick. Went over to take pics of the welded subframe and the car is all but back together from yesterday afternoon when they got it back.

 

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Discussion Starter · #20 ·
Now the sad part is the rear half of the driveshaft hit the exhaust during the failure and the balancing weight got whacked off. Also the rubber boot tore. BMW quoted them $1,200 for a new shaft. Both halves. They don't/wont sell just one part of it.

Suggestions? They think they can get it rebalanced, but they do need that rubber boot back there. Can that be replaced by itself? Remanufactured shaft? Used from Clemster?
 
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