The definitive subframe strategy thread

[Randy Forbes]

What is your opinion on this method?

My 1999 supercharged M Rdstr uses that configuration.

[lcjhnsn]

Another member has entered this dubious club :-(

I purchased a 2000 M Roadster on ebay around Labor Day and tried to convince myself that this problem only affected a few folks who had been abusing their cars and that I didn't have to worry. Unfortunately, while poking around under the trunk liner yesterday, i discovered a signifiicant tear of the longitudinal seam weld joint along the left side of the trunk floor.

I've listed my name and situation on the Class Action Attorney's web site and will be discussing the situation with my local BMW Center on Monday.

Are there any other engineers here who have done any objective thinking about the loading conditions in play here and other options regarding repair and prevention?

damn!!

[mako18]

Updated my previous post guys!! FYI

[Wojtek79]

I was just thinking, and wanted to ask if a car has a good subframe, would switching to a dual ear diff help prevent damage?

[Randy Forbes]

I was just thinking, and wanted to ask if a car has a good subframe, would switching to a dual ear diff help prevent damage?

Done appropriately, yes.

[Z3POWER]

Randy are you referring to reinforcing just the one diff mount?

This was conducted by the BMW Dealership back in 2001.
They doubled up on the brackets. Took one and welded onto the damaged unit. No issues since then.


Here is my writeup on this.
Z3Power.net - repair of subframe

[MMMGood]

I had read where the aluminum chassis on the Z8s are bending -- obliterating the value of the car. If so, it seems that BMW has some real chassis issues on limited production cars. Maybe the Z8 could be additional proof of that.

[MMMGood]

Thank you for the comments. This issue is the only thing holding me up from pulling the trigger on one of these cars. I've got a call in to Dinan to find out more about their diff reinforcement kit and the labor cost to install.

I installed one on my 2000 M coupe. The guy who did it was a body shop that specialized in Bimmers. He was pretty impressed with the Dinan setup.

[MC28REPSOL]

any Pics of the Dinan set up?

[2000Z3M]

MY car is finaly going to get fixed!!!!!

[AthleticTrainer]

MY car is finaly going to get fixed!!!!!

About time man! When are you going to be deployed? Any chance of stopping by soon???

[hognfrog]

Hello,
New to this Bimmer forum and this is my first post.

I am considering buying a 2000 Z3 from a local Dealer and want to make sure I don't have the sub frame problem before I buy the car. I have read some of the posts and from what I gather I can detect a problem if I look in the trunk under the trunk liner....is this correct??
Is there another place I can look without taking the wheels off or anything like that since the car is sitting on the dealers lot.
I love the car and it has LESS than 10,000 miles on it, but don't want to run into a problem.
Thanks in advance for any advice.

[JBgotM]

Hello,
New to this Bimmer forum and this is my first post.

I am considering buying a 2000 Z3 from a local Dealer and want to make sure I don't have the sub frame problem before I buy the car. I have read some of the posts and from what I gather I can detect a problem if I look in the trunk under the trunk liner....is this correct??
Is there another place I can look without taking the wheels off or anything like that since the car is sitting on the dealers lot.
I love the car and it has LESS than 10,000 miles on it, but don't want to run into a problem.
Thanks in advance for any advice.

with under 10k miles, I would be shocked to see any damage. If you would like to take a look.

-Open trunk
-lift carpet floor
-unscrew the drivers side tool tray and lift to expose the area most prone to damage. You will see a few spot welds about 3/4 the way back of the trunk.

[Randy Forbes]

Hello,
New to this Bimmer forum and this is my first post.

I am considering buying a 2000 Z3 from a local Dealer and want to make sure I don't have the sub frame problem before I buy the car. I have read some of the posts and from what I gather I can detect a problem if I look in the trunk under the trunk liner....is this correct??
Is there another place I can look without taking the wheels off or anything like that since the car is sitting on the dealers lot.
I love the car and it has LESS than 10,000 miles on it, but don't want to run into a problem.
Thanks in advance for any advice.

Yes, as Jason says, not likely, here's where you want to look (this is a Z3 Coupe picture__thanks to speed of sound__but the Rdstr looks identical).

Welcome to the forum, and don't let the trunkfloor issue throw you off, they're still great cars!

[hognfrog]

Wow,
Fast on the reply.
I am doing a little price researching to determine what I should "offer" the dealer on this Z3. I looked it over on the lot and could not find a mark on it. Even the nose is clean, no evidence of repaint or anything.
I think I will move forward on this and make my inspection and see what they have to say to my offer.
Thanks again for all the help.

[jackool]

Let us know if you buy. When your'e inspecting trunk, you may want to let them know that you are aware of this potential problem and its' cost to fix. ($3K) It may help you in your negotiations as you can be reasonable sure they know of this attribute and hope buyers don't.

[carsonquinn]

OK you can add my 1998 M Roadster to your list of failing subframes. The car has 65k on it as well as a Dinan Supercharger. Three spot welds in trunk are sinking and there is a tear on the diff mount. My email is carson.quinn@gmail.com

[Maxspeed]

Hi folks,
My name is Max and i am 17, I have bought a 1998 m roadster last summer and guess what the subframe failed. It has 117000 miles and the modification are dinan chip, and air intake. Now i am already trying to fix it on my own but it is really a mess a lot worse than what i have seen on youre cars. I have been talking whit my dad about the problem and he told me to maybe make a mold and die cast a all new subframe or just add some torsional strenght to the subframe, anyhow i need the dimension of the subframe but because mine is really badly hurt i was wondering if you had the dimension????
thank you
Max
My email is mgarau7@hotmail.com
P.S sorry about the english I am french:S

[Randy Forbes]

Hi folks,
My name is Max and i am 17, I have bought a 1998 m roadster last summer and guess what the subframe failed. It has 117000 miles and the modification are dinan chip, and air intake. Now i am already trying to fix it on my own but it is really a mess a lot worse than what i have seen on youre cars. I have been talking whit my dad about the problem and he told me to maybe make a mold and die cast a all new subframe or just add some torsional strenght to the subframe, anyhow i need the dimension of the subframe but because mine is really badly hurt i was wondering if you had the dimension????
thank you
Max
My email is mgarau7@hotmail.com
P.S sorry about the english I am french:S

You may have your own reasons for wanting to do it that way, but I can't help but think it would just be easier to buy my reinforcement package and patch up what you have. Once the kit is installed, the OEM crossmember is little more than a dust-cover anyway, so it matters little that it's patched together.

Naturally, this is a biased opinion...

Follow along with the latest car I'm working on at http://www.rfdm.com/gallery/album55 though there won't be too much progress over this weekend.

[Maxspeed]

Thanks for the quick reply too bad you don't have the dimension. How much would your package cost and can do you the fix ? If you can how much would it cost?

Max

P.S:i forgot how much does the differential cover whit 2 attach point cost?

[Maxspeed]

I have added some pictures of the car and the subframe on that site if you want to check it out.
s117(dot)photobucket(dot)com/albums/o65/Maxspeed7/

Max

[MC28REPSOL]

You may have your own reasons for wanting to do it that way, but I can't help but think it would just be easier to buy my reinforcement package and patch up what you have. Once the kit is installed, the OEM crossmember is little more than a dust-cover anyway, so it matters little that it's patched together.

i agree with Randy.

after looking at solutions from different manufacturers. i chose Randy's Kit, do to the fact that it was the Best (IMHO).

i can't see anyone trying to come up with their own solution. since there is a repair kit that is well made already on the market and readily available.

just my 2 cents.

and Good Luck in fixing your car. it's worth it!

[MP525i]

well since i had some time today, i checked my rsm's along with my subframe. everything seemed ok for now, but i would still like to get randy's kit asap!

hopefully in another month or two i'll be able to get it.

question: has anyone done this fix, and tried to get bmw to reimburse them? granted, it's probably a hail mary, but don't you think it's worth a shot?


randy - with your kit, what type of after market exhausts are we limited to? i would like to go active auto down the road...

thanks!

-mike

[Randy Forbes]

well since i had some time today, i checked my rsm's along with my subframe. everything seemed ok for now, but i would still like to get randy's kit asap!

hopefully in another month or two i'll be able to get it.

question: has anyone done this fix, and tried to get bmw to reimburse them? granted, it's probably a hail mary, but don't you think it's worth a shot?


randy - with your kit, what type of after market exhausts are we limited to? i would like to go active auto down the road...

thanks!

-mike

I got my local dealer to install my kit on both of my cars. That was the (un)official endorsement that I was on the right track with my design. They were prepared to cut the car(s) in half and install the entire new rear clip. When they saw the reinforcement, there was no question about which would be the better long-term repair (same problem in a few more years with the new clip).

DragonM had my kit installed by a local SoCal collision repair shop and (had to go to court, but) was reimbursed by BMW. Do a search on Bimmerforums for details.

As for the exhaust, any aftermarket system that has the tailpipes entering the muffler can in the center to outboard portion of the oval will work. The OEM exhausts have the pipes entering the mufflers on the extreme inboard side of the oval, by comparison.

[Randy Forbes]

Thanks for the quick reply too bad you don't have the dimension. How much would your package cost and can do you the fix ? If you can how much would it cost?

Max

P.S:i forgot how much does the differential cover whit 2 attach point cost?

I don't post prices on the forums, as I'm not a supporting sponsor, but you can E-mail me and I will reply with a canned pdf that outlines the work.