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View Full Version : Mod advice: Trailing arm, control arm, and sway bar



justinbiomechanics
03-21-2015, 10:10 AM
Dearest TM3,

I have inherited my wife's 2008.5 3, and am overall impressed (i came from a 2001 VW TDI w/t 500k on it). Dealer recommended a bunch of changes at the last oil change most of which I just did myself (the low hanging fruit; filters, plugs, etc. saving ~ 500), I have yet to change out the # 3 engine mount, but will when it's nicer out.

My questions:

1) Rear trailing arm bushings: Select Mazda quote $850 to replace, I have not noticed any clunking from the rear of the car. Is this a "when and not if" kind of failure, and should I just do it now? (seems like a common theme in this thread from my research, but the price is kind of shocking)

2) Right rear control arm: SM quoted $375 to just replace the whole arm, even though just the bushing is "gone". Still not noticing any symptoms. Should I change this to prevent any issues down the road? Or wait until I'm having issues?

3) My only complaint about switching from a VW to a mazda is i notice significantly more "looseness" while turning at speed (eg taking on-ramps at speed), I notice the car doesn't feel like its' hugging the road as much. From my research I seem to think that it's body roll that I'm experiencing, and that sway bars are the way to go. Does this sound reasonable? I've looked at putting in a rear sway, which seems easy enough but the front looks tricky. Is it worthwile doing only the rear DIY and getting someone else (like putney's or dynomotion in burlington) to do the fronts.

4) I know this isn't the dealer review section, but has anyone else noticed a decline in Select Mazda's service? I used to be impressed with them, but it seems lately the wheels have fallen off, so to speak.

Thanks for reading!

Jackal
03-21-2015, 11:30 AM
For #3. Rear sway bar will help as well as lowering it slightly.

FD22
03-21-2015, 12:17 PM
My questions:

1) Rear trailing arm bushings: Select Mazda quote $850 to replace, I have not noticed any clunking from the rear of the car. Is this a "when and not if" kind of failure, and should I just do it now? (seems like a common theme in this thread from my research, but the price is kind of shocking)

2) Right rear control arm: SM quoted $375 to just replace the whole arm, even though just the bushing is "gone". Still not noticing any symptoms. Should I change this to prevent any issues down the road? Or wait until I'm having issues?

3) My only complaint about switching from a VW to a mazda is i notice significantly more "looseness" while turning at speed (eg taking on-ramps at speed), I notice the car doesn't feel like its' hugging the road as much. From my research I seem to think that it's body roll that I'm experiencing, and that sway bars are the way to go. Does this sound reasonable? I've looked at putting in a rear sway, which seems easy enough but the front looks tricky. Is it worthwile doing only the rear DIY and getting someone else (like putney's or dynomotion in burlington) to do the fronts.

4) I know this isn't the dealer review section, but has anyone else noticed a decline in Select Mazda's service? I used to be impressed with them, but it seems lately the wheels have fallen off, so to speak.

1) These are definitely items that do tend to go on our cars as the mileage gets higher. You'll start to feel it when it goes though, so at least you'll have some notice that way. As for the price, I'm guessing that included install too? In which case, it seems about right. The parts themselves should be a fraction of that though. I would recommend getting the parts from Mazda and having your regular mechanic install them. Saves you a ton of money.

2) Fairly certain you can just replace the bushing if that's the issue. You don't have to replace the whole arm/assembly.

3) As Jackal mentioned, the rear swaybar will help, as will a stiffer/lower suspension. The front swarbar is actually very easy to DIY, so look into that too.

justinbiomechanics
03-21-2015, 01:37 PM
Sounds totally reasonable! I like the idea of not paying dealership labour. The prices did include labour, from what I've seen the bushings are $30-60 ish, seems the RTA bushings are a bit of a pain to swap out. I just looked one of the manuals and it totally looks reasonable! That's on the to-do list this spring!

justinbiomechanics
03-21-2015, 01:37 PM
For #3. Rear sway bar will help as well as lowering it slightly.

That's what I figured. Thanks for the reply!