The definitive subframe strategy thread

[Mr Bingley]

It would be nice to see what's going on under the tool tray (and under the sound deadening).

[rf900rkw]

I was gonna say.... pictures of absolutely everything except where the failure starts.

[Randy Forbes]

True, but IF there's any damage, it would still be in the infant stages. If there was any advanced separation, you can see that through the asphalt mat.

I would say that the seller was very compliant with your wishes, considering your opinion of his knowledge of the car! Without significant effort, those are about the best pictures you're going to get.

I'm looking__as close as I can__at pictures # 2, 4, 8 & 9 (poor focus) for any fractured spotwelds, and I can't see any (doesn't give the car a 100% clean bill of health, but nothing obvious).

THANK YOU for putting a space between each image tag! Even though I know what I'm looking at, clearly defining where one pic ends and the next begins makes a huge difference (as I've pointed out on this forum in the past...).

If you can make a good deal on the car, it doesn't look like there's too much here to hold you back__if you do wind up having to do a repair/reinforcement, it won't be for a while

[TheBigChill]

Edited for double post.

[TheBigChill]

Thanks guys,

Yeah- the seller, understandably, is hesitant to start ripping up matting in the truck, for a guy he doesn't know 300 miles away, for a problem that he doesn't think exists. I had to send him several images of what the diff and diff mount looked like, just so he could find his, and the result is these half-useful photos. The photos he DID take I appreciate enough. The cracking in the matting itself had me spooked, but I doubt it's anything related based on the location.

That said, I think I can grab the car for $7,000 - $7,500. Again, it'll need one RSM, full cooling refresh, headliner repair, battery, rear diff bushing, and of course...all fluids changed. What say you?

[Remotion]

Is there a way to have only dual ear diff cover without extensive restoration of car?
Does anyone sell just dual ear mounts for our cars?

- - - Updated - - -

I think the single crack in the mat can be just because of mat material and age. Not tell tale for something bigger. But don't keep me accountable if it is.

[TheBigChill]

Bumping this up one more time, gents.

I'm looking at another 2.8 Z3 Coupe, this time a much better maintained one. Again, after explaining this potential issue to the owner, they were unaware of it's existence. After explaining where to look, the owner, without hesitance, marched out to his car, took some photos, and with very little direction he started tearing into his asphalt mat to expose some spot welds for inspection. Props.... Anyhow:

Two of them look OK (the welds that hold the Diff ear), but the other one looks popped to me. Can I get your thoughts on this, guys? Thanks

[Mr Bingley]

The bottom picture looks popped to me. Nice of the seller to just go digging into his asphalt mat like that--you certainly can't fault him on his honesty.

[TheBigChill]

I agree. The bottom photo looks popped to me, too. You can clearly see two different layers in the spot weld, compared to the other smooth spot welds in the first photo.

I've passed this info on to the seller, though it's sometimes hard to convince people that the issue does in fact exist, and the severity of it.

The car seems very good otherwise, but this is a big and expensive fix. Any advice on moving forward? Car has good maintenance history, a seemingly responsible owner, and low-ish mileage w/ records.

The car is no longer a good buy once the Randy Forbes fix is installed ($800 parts +$2500 install).

[Randy Forbes]

I agree. The bottom photo looks popped to me, too. You can clearly see two different layers in the spot weld, compared to the other smooth spot welds in the first photo.

I've passed this info on to the seller, though it's sometimes hard to convince people that the issue does in fact exist, and the severity of it.

The car seems very good otherwise, but this is a big and expensive fix. Any advice on moving forward? Car has good maintenance history, a seemingly responsible owner, and low-ish mileage w/ records.

The car is no longer a good buy once the Randy Forbes fix is installed ($800 parts +$2500 install).

Ask if they'd be willing to subsidies all or a portion of the cost. All they can say is yes, no or half (perhaps the "no" might come with some embellishment...) but it sounts as though you like everything else about the car, and this seller has come this far with you already.

If it's a Z3, with a spare tire carrier that you want to keep intact, then as an example only, that's a job I routinely do at a fixed cost of $2550.00 (plus local tax) including all parts; I'm about to do the same job on the One of None Imola Red/Walnut Extended Leather M Coupe now (because this particular owner wants to maintain a stock appearing vehicle).

[TheBigChill]

Thanks guys.

Randy: What would it cost without keeping the spare carrier intact? Also, do you have recommended installers in the NY area? I know your competitor, Mr. M Car, does something different in NJ.

Also, since you see more of these cars than anyone else, what say you of that last weld?

[Bruceski44]

Hi all. N00b here considering buying a 2000 M Coupe. Going to look it over later today.

I've read almost the entire thread (whew!) and want to check my understanding by seeking the answer to two questions below.

Two questions:
1. Is it safe to say that even if no evidence of pulled spotwelds exists that it's just a matter of time before the problem appears? Especially considering I'd be the 6th owner and have no evidence of previous owners' driving style? We can call my intended usage "spirited" road driving with late threshold braking and high cornering speeds. Some full-throttle acceleration to legal speeds. Regular RR crossings in my city.

2. On a quick inspection, if I see the one-eared diff mount can I safely assume that no strengthening of the area has been performed?

This would be my first BMW. I've always liked the looks of the M Coupe and want a fun-to-drive car. If my understanding of the problem is correct, I'll try to account for the expected repairs in my purchase offer.

Thanks for any and all helpful comments.

[Randy Forbes]

Hi all. N00b here considering buying a 2000 M Coupe. Going to look it over later today.

I've read almost the entire thread (whew!) and want to check my understanding by seeking the answer to two questions below.

Two questions:
1. Is it safe to say that even if no evidence of pulled spotwelds exists that it's just a matter of time before the problem appears? Especially considering I'd be the 6th owner and have no evidence of previous owners' driving style? We can call my intended usage "spirited" road driving with late threshold braking and high cornering speeds. Some full-throttle acceleration to legal speeds. Regular RR crossings in my city.

2. On a quick inspection, if I see the one-eared diff mount can I safely assume that no strengthening of the area has been performed?

This would be my first BMW. I've always liked the looks of the M Coupe and want a fun-to-drive car. If my understanding of the problem is correct, I'll try to account for the expected repairs in my purchase offer.

Thanks for any and all helpful comments.

Q1: your intended use increases the odds, but still too many variables to positively say yes or no. Knowing this going in, I'd recommend that you start a slush fund for when/if that day arrives.

Q2: not necessarily; I've reinforced several (many, really) when the owner preferred to retain the OE differential cover with its single mount.

In closing, I'll also say that not all repairs are equally successful. There's a transplanted New Englander now living in Texas that had his car done locally up there on the East Coast some years ago (by a guy that bad-mouthed my work as being overkill, but now I'm just being petty ) who is currently redoing his M Rdstr with a reinforcement package sourced from me.

[Schreier]

Hi Randy, do you by chance know any shop or welders in Oklahoma or in the Dallas area who have installed your kit, with positive reviews?

Thanks for your support to the Z3 community!

[Pingu393]

This was my car just after I got it in Nov 2010...

Before, showing damage...

After, showing repair...

I also used a spacer washer to avoid pre-stressing the diff carrier "ears". I've had no problems with the car, despite this sort of thing...

[Randy Forbes]

Pretty sure it was a repair similar to what you had done that led to this; they're always worse the second time around!











Just welding things back together, even with an added gusset isn't enough to effect a permanent repair; you need to peel it back and reinforce the foundation.





Geez, I did that car ten (10) years ago; how time flies...

It'll be a while yet before I can get to it, but an S-52 M Rdstr showed up here last week that was__at least as seen from the topside__just welded back together, and it's now exhibiting a two inch (2") gap between the LH longitudinal rail and the main floor section. Eventually, it'll get its build album in the gallery.

[Mr Bingley]

Well Randy, that's pretty fugly--nice fix though.

[roadsterfan]

Has anyone seen or implemented the Thayer kit: https://thayermotorsports.com/produc...nt=14070742855

It looks like it would weld up quite similar to RF kit and is priced the same as Randy's kit. Is it a copy of Randy's kit or is it different?

[Randy Forbes]

Has anyone seen or implemented the Thayer kit: https://thayermotorsports.com/produc...nt=14070742855

It looks like it would weld up quite similar to RF kit and is priced the same as Randy's kit. Is it a copy of Randy's kit or is it different?

Jonathan buys them from me, so they are fully sanctioned, and I am happy to endorse buying them from Thayer Motorsports.

[JesusFreakToo]

Jonathan buys them from me, so they are fully sanctioned, and I am happy to endorse buying them from Thayer Motorsports.

Is there anyone in the Allentown PA area doing these "upgrades"? I have a 2000 M Roadster. 57K miles. No issues, but I would like to address preventively if not cost prohibitive.

If I am not tracking the car. Most of the time it is babied. is simply installing less flexible rear bushings enough "preventive" maintenance?

[khammack]

If I am not tracking the car. Most of the time it is babied. is simply installing less flexible rear bushings enough "preventive" maintenance?

The jury is still out on what actually causes the failure. Many seem to blame the rear bushings, but mine failed after a weekend road trip over some VERY rough roads in northeastern NM. There are many other theories, but I think several (many?) causes may exist. Many people have installed it to "prevent" the problem, but if you wait until you start seeing issues, you should have time to get it fixed. Mine occurred at about 110k miles and I drove it (even autocrossed it) for a few months before I was able to get it in to have Randy's kit installed locally. Your car may not ever have the problem.

[dstraigh]

@JesusFreakToo - I got the Randy Forbes Kit installed a few years ago - never looked back and really happy I got this kit. It's not just a fix it's an upgrade.

[Mr Bingley]

@JesusFreakToo - I got the Randy Forbes Kit installed a few years ago - never looked back and really happy I got this kit. It's not just a fix it's an upgrade.

Why the use of the @ symbol before the user name here? What meaning does this convey (just trying to stay on top of current punctuation usage trends)?

[Randy Forbes]

Why the use of the @ symbol before the user name here? What meaning does this convey (just trying to stay on top of current punctuation usage trends)?

It's pretty common on social media (at least Facebook, my only exposure) as a way to direct your reply back to the person most concerned to see it. Same as me using your...

post

... to answer your question

[Mr Bingley]

It's pretty common on social media (at least Facebook, my only exposure) as a way to direct your reply back to the person most concerned to see it. Same as me using your... ... to answer your question

@Randy Forbes--so it's like saying "Randy Forbes, this post is for your special attention, be sure to read it"? That would be a useful short cut. Is this usage generally recognized? I have never actually looked at a Facebook page, or other social media content, so sometimes these innovations catch me off guard. Although I think of this forum as being a kind of social media--albeit antiquated and extremely focused.