Check sway bar ends. The bushing is perished.

 

Excessive positive caster can cause bump steer. Who ever did your alignment should have done a full front end check as it's futile doing an alignment with worn out components. That said maybe they didn't check that thoroughly.

 

+1 for end links and possibly control arms

 

A more careful inspection of the 2004 Matrix XR AWD shows rear shocks that need replacement. Am hoping this caused the jumping in the rear over bumps. Anyone know if the Quick combo - springs and shocks - are available for the rear in an AWD? Or is it possible to just replace the rear shocks without compressing the springs?

 

Quick struts should available for sure. Struts can be replaced by themselves, but no you have to disassemble the strut assembly using a spring compressor.

I doubt worn out rear struts are causing that even if severely worn out. But worth changing if worn out. Save yourself some tire wear.

 

Thanks. I see that so many of the companies specify their Quick struts for the rear are for FWD. So when I see a company with a Quick strut for the Matrix rear and there's no specifying AWD or FWD, I'm leery that it will actually work for AWD. But like you say, there should be some available.

 

Yeah yours will likely be different because of independent rear suspension. I don't know if the FWD matrix has independent suspension or not, I don't believe it does. Hopefully someone can give you a part number.

 

The fwd matrix uses torsion beam on the rear suspension.

Just checked with RA and they only have fwd. Some of the others don't specify trim or AWD.

 

I went to get some new rear shocks installed after seeing that one leaks. I was told that the control arm would have to be removed and that means an alignment would be needed. Since that garage doesn't do alignments, they didn't do the rear shocks. Make sense...but I wonder if they might have been looking at the front instead of the rear. To replace the rear shocks, does the upper control arm have to be removed?

 

What kind of mechanic won't replace shocks? I'd find another garage lol.... Sounds like he doesn't know what he's doing. Most mechanics will do the shocks then send it out for alignment if necessary...

 

I would be very surprised if you had to remove control arms to get the strut out. Maybe undo the ball joint to allow removal room. But the whole arm? Hopefully someone here has had the pleasure of pulling them.

The obscenities I've yelled at some awd vehicles when trying to remove rear cv axles on the other hand ...lol.

 

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This what your rear suspension looks like;

I'd strongly suggest to check "control arm" bushings as they control side to side movement of the entire assembly. Along with the torsion beam bushings. Struts normally simply give very bumpy ride but not really side to side wobble. Strut is up/down, trailing arms and "control arms" are side to side.

http://madstyle1972.com/Repair/27/200qpl02/w040001.pdf

List as follows:
2-API 270097342 Sway Bar Link Or Kit; 4 WHEEL/ALL WHEEL DRIVE,COMPLETE - REAR; Base Model
2-ULTRA-POWER K80230 Front; Base Model
1-MONROE 172116 Quick-Strut Front Right
1-MONROE 172117 Quick-Strut Front Left
2- MONROE 71375 OESpectrum Strut REAR; AWD
2-MONROE 904990 Strut-Mate Strut Mounting Kit Rear

 

I agree with above, shocks will not cause this issue. If the shocks are not causing a very bad ride quality, they're probably OKAY for now. Leaking shocks isn't a huge deal, it just means they are nearing end of life but so long as they are still giving a quality ride I'd leave them alone.

 

Very helpful comments regarding my Matrix swaying/'jumping' a bit over bumps. Changing the rear shocks did help quite a bit. Now with snow and ice, the side to side movement is still noticeable.

My son has the car now and he looked and saw that one of the rear upper control arm bolts was loose. The control arm could move or shake. So the comments above about control arms/bushings are right on. Thanks.

The control arm bolt broke when he tried to tighten or remove it. But here's a question: If the bushing is worn, I see that there are control arms that say specifically "For Matrix AWD". These have a special adjustment end on the arm in case the Matrix AWD is hard to align for various reasons. Does an AWD Matrix require one of these special rear upper control arms?

 

Very helpful comments regarding my Matrix swaying/'jumping' a bit over bumps. Changing the rear shocks did help quite a bit. Now with snow and ice, the side to side movement is still noticeable.

My son has the car now and he looked and saw that one of the rear upper control arm bolts was loose. The control arm could move or shake. So the comments above about control arms/bushings are right on. Thanks.

The control arm bolt broke when he tried to tighten or remove it. But here's a question: If the bushing is worn, I see that there are control arms that say specifically "For Matrix AWD". These have a special adjustment end on the arm in case the Matrix AWD is hard to align for various reasons. Does an AWD Matrix require one of these special rear upper control arms?

The awd matrix and fwd matrix have completely different rear suspension. I'd assume it's needed...