Rear end

[Damian]

OK so I was driving around last week and was taking a decent left curve at highway speeds. Might have been pulling half a lateral g or more. Suddenly my back end feels like it slides out ever so slightly and my DSC light starts to blink.

I have a few other things I needed/wanted done so I drop it off to my Indy. After stopping in to check progress today he tells me that the spring was out of where it's supposed to be settled and he can't figure out why. Rather than just put it back and call it a day he decides to investigate what caused the problem to begin with.

Last year I had him change out my rear diff and diff bushings from AKG. He gets a pry bar to check anyways and no movement from diff. I started bouncing ideas off him (shock mounts, spring perch, sub frame mounts) but he says they checked each of those and they were fine.

Lastly, I know one of the rear LCA were bent (PO likely had it towed at some point) so I bought an adjustable performance set from ECS for him to install, along with front shock tower reinforcement plates and a new ccv system. Since the alignment was only slightly out of spec we don't suspect this was the cause.

His most senior mechanic is back on Monday but I figured I would ask the Mafia, have you guys seen anything like this happen before?

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[ZacharyMikel]

have you guys seen anything like this happen before?

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So I'm confused on what the issue is... It feels as if the rear of the car is sliding out and the DSC light is flashing when you're in a mild corner that shouldn't cause those things to happen?

[Damian]

Yes. Getting a big amount of oversteer where I shouldn't be.

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[09mageec]

How are your tires?
Also, are you on aftermarket springs/suspension? If so, when the car is on a lift and there isn't any weight on the springs (rear end only), they will be able to move around a bit, as they aren't compressed.. I cant remember how much play, if any, that there was with my stock spring and suspension setup.. It doesn't sound like this is the problem.

[Damian]

Rear tires were just replaced, old ones were pretty worn on inside. Stock suspension setup for now. With the car up I didn't think there was supposed to be any play but don't see any other explanation...

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[ZacharyMikel]

Rear tires were just replaced, old ones were pretty worn on inside. Stock suspension setup for now. With the car up I didn't think there was supposed to be any play but don't see any other explanation...

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DSC wouldn't flash unless the tires were actually spinning, right? Did the new tires fix the issue?

[russiamutha]

worn RTABs will cause your car feel a bit "skittish" and your DSC light will blink when that happens.

[09mageec]

Rear tires were just replaced, old ones were pretty worn on inside. Stock suspension setup for now. With the car up I didn't think there was supposed to be any play but don't see any other explanation...

So, have you had this issue since getting some new rubber back there, or are you saying this is still an issue even after mounting fresh tires?

Also, I just want to reiterate.. You said that you were taking a "decent left curve at highway speeds". There are a number of things that could make your car lose a bit of traction while turning at those speeds (I'm assuming 55-65mph) and cause your DSC light to give a quick blink - As russiamutha stated, there are bushings, that if worn/failing, can make your back end quite loose. As I said before, worn tires, failing suspension parts ie. shocks/springs can give that sloshy/loose feeling as well.

Try taking a tighter turn at a more comfortable speed. I wouldn't suggest taking any non-highway turns at highway speeds..

[Damian]

Problem solved!

This happened both before and after getting new tires on rear. RTA and bushings were fine but I decided to change it for any adjustable unit from ECS. It looks beautiful...

As it turns out the culprit was that my right rear spring had come out of its home due to worn rubber perch and the spring was sitting cockeyed. It seems the angle was not conducive to predictable compression/rebound since it was getting hung up on adjacent sheet metal.

He asked if i had taken a high speed curve and got hang time in the process as he said it would take a combination of those two to exert enough pressure to cause this to happen. There was one time coming through the canyons last year that is the closest time I can think this could have happened, yet I digress.

New rubber spring seats coming in from stealership today and car should be up and running tonight. Thanks for your ideas!

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[09mageec]

Problem solved!

This happened both before and after getting new tires on rear. As it turns out the culprit was that my right rear spring had come out of its home due to worn rubber perch and the spring was sitting cockeyed. It seems the angle was not conducive to predictable compression/rebound since it was getting hung up on adjacent sheet metal.

He asked if i had taken a high speed curve and got hang time in the process as he said it would take a combination of those two to exert enough pressure to cause this to happen. There was one time coming through the canyons last year that is the closest time I can think this could have happened, yet I digress.

New rubber spring seats coming in from stealership today and car should be up and running tonight. Thanks for your ideas!

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Ahhhh, that'll do it! Glad to hear you're getting everything tightened back up! Bump

[Damian]

Ahhhh, that'll do it! Glad to hear you're getting everything tightened back up! Bump
Nothing quite like a tight rear end! [emoji4]

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[09mageec]

++++++1 :applause