Is the Rear Subframe Symmetrical?

[GOT8SPD]

I put new AKG poly RTAB on because the rear tires were wearing pretty bad. It looked as if the toe was off based on the tire wear and how it wore.

After replacing them, i STILL have really bad tire wear because the camber is off.

I took my car to an collision shop and they said that my rear sub frame was slightly tweeked and that's what was causing the rear camber problem.

I bought a rear subframe and A-arms from craigslist....but is there anyway to make some "measurements" of some sort to see if the subframe i'm putting on is actually any good? I know it's a ton of work to put this thing on and i would hate if it doesn't actually fix the problem....I'm going through rear driver side tires every 7000 miles and i drive the car probably about 25,000 a year (i've had it only 2 years)

I used a tape measure and measured one point to another point, then did the same on the other side, and i'm getting conflicting numbers....off by almost 1/2", but i don't know if its suppose to me symmetrical...

Anyone have any ideas / tips? Thanks for your input!

[jlevie]

While a bent subframe is a possibility, that is rarely the cause of misalignment of the rear wheels. The more likely cause is a bent trailing arm. A curb strike (that doesn't even bend a wheel) is all it takes. Get the alignment numbers for the rear wheels and replace the arm(s) based on the errors. If the alignment numbers are still way off after that, replace the subframe.

Changing the subframe isn't that hard of job.

Remove the cat-back portion of the exhaust.
Pull the rotors, disassemble the parking brakes, & pull the cables.
Disconnect the sway bar links & and shocks.
Disconnect the wheel and differential speed sensors.
Disconnect the driveshaft at the differential and the differential bushing.
Support the subframe assembly with a floor jack (or better yet with a transmission jack).
Drive the subframe bolt up and out of the bushings.
Lower the assembly and roll it out from under the car.

Installation is the reverse.

I've had a little practice at this and can get the the subframe in or out in a couple of hours.

[GOT8SPD]

It doesn't matter if the rear subframe is symmetrical or not if its like this.....

When the collision shop said "it's slightly tweaked"....well...quite the understatement...

I'll let the pictures do the talking...







The rear diff was basically being held on only by the 4 bolts that held it to the center drive shaft and the rear diff mount!

This is my first time removing the whole subframe...i'd like to share some thoughts...

I think that if someone is replacing a subframe or subframe bushings, it's much easier when you have 2 people....if you don't have two people, it's best to disassemble everything one piece at a time. Even putting it back together, it's easier to put the thing back together one piece at a time. My friend and I tried to put the a-arms and subframe only but it was still too heavy for us and we had a hard time getting the center drive shaft through the subframe and get the subframe lined up with it's bolt...maybe we're just little girls. :giggle:

If it's only one person doing this, take apart the brakes, disconnect sway bar, remove the axles, trailing arm, and diff and then subframe. Kudos to those who can remove it all as one package. Sometimes the longer way is the easiest way...

I put Power Flex Street sub frame bushings on it while i tackled the project. Also paid someone to remove the subframe bushings....i see lots of different tools people have created etc...just not worth the time IMO.

How long as it been like this? I have no idea....I did not expect to find this when tackling this project. The collision shop didn't charge me to inspect it, i still gave them $20 for their time to look at it. I only was going to replace the subframe because they told me it was tweaked. If i knew that the diff wasn't even bolted on the subframe, i would have stopped driving the car. It's probably been like this for easily 20,000 miles my guess is (i drive about 20-30k a year and this is my "extra" car). My intention was only to fix the subframe in hopes that it would correct my negative camber issue that was KILLING my tires....but looks like i fixed a whole lot more....I can't wait to go drive this thing...it was so fun to drive before even while not knowing the actual state of the car!

It's not completely back together because I can finish it tomorrow or another day...too much work for one day. Still have to put the whole brake system on and the rear diff and axles, but I put the wheels back on to inspect it's stance and my camber issue is gone!

Thanks for everyone's help / input as I've made a few threads and have asked numerous questions....in the end it was a subframe...

[Massimo]

Holy fuck. Is there any massive cuts on the bottom of the diff? I ask because I am wondering if the diff hit something once which cause the subframe to break like that.

You are lucky the diff did not twist on you and rip your CVs apart.

[Holland]

How in the hell would it have even ended up like that in the first place? Accident damage? It's definitely not natural for that to happen.

[jlevie]

How in the hell would it have even ended up like that in the first place? Accident damage? It's definitely not natural for that to happen.

Loose (or missing) differential bolts can cause that sort of damage.

[GOT8SPD]

When i bought the car two years ago (Today is it's 2nd birthday!), when shifting from 1st to 2nd under hard acceleration, you'll hear this loud ass BANG coming from the back. After checking out the rear end, the shocks in the back were completely blown. I replaced them and the banging sorta stopped. It only happened sometimes now. Under normal driving it never happened.

I replaced my RTAB a few months back, during that time, i did notice that the diff bolts were loose, so then tightened them all up....was it already too late and it had already ripped the metal so i was only tightening a broken piece of metal on to the diff? Probably...