84k. Replace struts? Any good tests?

[TurnAround]

3.0i Non-sport susp, 84k. All front control arms & bushings have recently been replaced. New Pirelli Scorpion Zero tires (nice and stiff side walls). Stock front sway bar.

I've gotten much.. errr, maybe even most ... of my X back to the way she used to handle in the corners. Still though, I can feel some body roll she never used to have. There is no question for me that my shocks are worn some and are contributing to the roll. The question is, at what point can a person say, "Ah, ok, these are really quite worn out and its time to replace them". Is there a decent test to find out? New front struts and rear shocks + labor aren't cheap, and I would prefer not to pull the trigger on it only to get them on and find out they were really only 25% worn out and it improved the cornering only slightly and should have waited until 100K+.

The shocks were a good 80% worn out / gone on my Z3 Coupe at 50k. But.. that's a different car. One can't help but look at the large size of the X shocks and conclude, "Gosh.. these are heavy duty. They have to last longer, eh?".


Note on lowering; I realize that when I do replace them, that is my shot at lowering too. I've been researching this board. I think my conclusion is that my X would look a little cooler if it was 1" lower, but from what I'm reading it won't necessarily make it handle flatter and have quicker more go kart like handling, and in fact may make the handling worse. Reading it would definitely make the camber worse (Although.. I thought the rears could be adjusted some?).

2" or more lower.. I don't think I have wide enough wheels to match that look (Would also need the 4.6 / 4.8 fender flares), plus I'm realizing that for me its not my look on this car.

But back to the 1", I'm reading that after market Bilsteins are going to be substantially stiffer in ride quality and poorer ability to handle subtle road surface and cornering adjustments as compared to OEM valving and rates throughout the stroke. Plus, it sounds like the Eibach and H&R springs add more stiffness that I'd be happy with. I wouldn't mind a 10% harsher ride quality over OEM, but more than that would not be good. Its a bummer, because with my Z3 Coupe I was able to arrive at a very good comfort / to flat cornering compromise with my TC Klein lowering kit and with adjustable rebound damping.

As much as I'd like to get the X an 1" lower, I'm leaning away from the one spring / shock solution that seems to be out there (Don't want to make myself afford coil overs). So.. for new struts & shocks I'd probly go OEM.

[TurnAround]

Darn, I forgot an important question:
I have the non-sport now. What, exactly, makes up the sport suspension? Just springs, or, springs, plus the shock's valving?

Wait.. more dumb questions; When I replaced my Coupe's struts I just pulled out the old ones and recycled them. I never could determine... with OEM front struts, can a person just replace the shock, or do you always have to throw away the shock and the spring as one unit and start over with an all new combo unit? 'Cuz on my TC Kline struts, I can disassemble the shock and the spring and replace separately.

[lo_jack]

I have 135k on mine...and they are finished. I probably should have replaced them 40k ago.

I booted up the TIS the other day to check this process out, and it looks like you can get a set of spring compressors and pop the spring off the old strut, and put it on the new one with new hardware. That also appears to be the time to put camber plates in if you are going to do so.

[tonggi]

Unless your OEM springs are rusted. You can re use them

[4.6toddy]

The difference in re-using a the front spring vs. buying a complete unit (often termed a quick strut) comes down to labour.

I've done this homework for many customers and it comes out fairly flat using flat rate book times. The fee most shops charge to compress the spring and take it off the strut offsets the cost of buying a complete quick strut assembly.

Having said that, I don't have a BMW quick strut, nor do we work on BMW's so the figures may be slightly skewed compared to Chevy, Ford, Dodge etc.....