Hey guys. So as the title says, both of my front sub frames are rotting out (Not surface rust, rot). I brought my car to two different mechanics in my area. One was an Audi/Volkswagen specialist in Boston (Woody’s in Allston, MA), and the other was a co-workers close friend (Williams Automotive in Randolph, MA). I originally brought the car to Woodys garage right after I bought it. Although I’m good with a wrench, and my brother is an ASE certified gear head* (read below), neither of us have worked or owned an Audi/Volkswagen, so I thought bringing it to specialist would be a good start. Woody’s found the rot when he was replacing my control arms. He said he had never seen rot there on a B5 before. After paying an arm and a leg, I brought it to Williams automotive for a second opinion. Williams found the rot on both sub frames and suggest I get rid of the car ASAP, he also had never seen rot there on a B5.

My theory: The car has no splashguards or timing belt cover. My theory is that it was driven in the rain for so long that water collected and sat right on the sub frames unnoticed by the previous owners. Water leads to surface rust, surface rust leads to rot

I bought the car a month ago from a good friend with 200,000 on the motor, new clutch and a transmission with 120,000. The car is a 1996 2.6 12v Quattro with 205,000 miles on it, so the simplest answer is ditch the car. But there’s a catch, I love this car (Magnaflow exhaust, ST coils, S4 wheels, S4 seats, ect ect ect) and have a perfectly working 2004 chevy tahoe to drive if I decide to swap out the motor while I’m replacing the sub frames. So the question is where does one go from here?

Possible options:

1) Pull the motor and replace rotting control arms, replace original motor
2) Pull the motor, replace sub frame and install lower mile 2.8 12v
3) Pull the motor, replace sub frames and install 1.8T
4) Pull the motor, replace sub frames and install a tuned 1.8T (racecar!)

I am really pushing for option number 3.I REALLY want a turbo. But Audi’s are so new to me it would be a challenge to do a motor swap. I was wondering if there was anyone that could direct me where I need to go. Either a lengthy write up or even a contact person that would be willing to work with me to do this swap. If a 1.8t swap is easier than I think than I wouldn’t mind upgrading the turbo and replacing my 2.5 mangnaflow exhaust with 3 inch and then tuning the motor.

ANY ADVICE OR DIRECTION WOULD HELP!

ASE certified gear head*: Got his ASE certification at a technical high school in Massachusetts, went to college, and is now an aeronautical engineer for GE. Has a daily driver and two project cars. He is not a “mechanic” but he knows his ****.

 

my subframe, a4 1996 Quattro auto, right front has golf ball size hole. Part from dealer is $660. Told me engine has to be suspended to replace. Have a good mechanic, would like to find less expensive part. will it screw up handling if only replace one side? Rest of car good shape. Yours sound like real safety issue. probably still get sticker in ma.not in me. they check.

 

You'll need to align it after since the control arm connect to it.

 

thanku steve, In closer inspection, the rest of the 'cradle' seems to be in good strong shape. Can't it be welded or repaired somehow? I'm sure it's got more life to it.
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