Sway when accelerating or decelerating

[white02tb]

I am new to this forum, I want to thank everyone for there input before hand.

I have a 2002 trailblazer LTZ I recently purchased that needed some work.
Things I've replaced so far include - both lower ball joints; left outer tie rod; drivers front and passenger rear sway bar links; rear pads and rotors; vvt solenoid.

The issue im having is now the when im driving and give it gas or let off from a hard acceleration I notice the whole truck sway from one side to the other. I did notice that when I had it on the lift on Friday the rear wheels had some play in them from the diff im assuming. not sure If that would be enough for the sway; also I know I need an alignment from doing the tie rod and ball joints haven't gotten around to it.

anyone encounter this issue? or sound like a problem caused by the rear end or alignment.

Also I could only assume that the stock struts and shocks are getting very loose - so im sure that doesn't help.

any input would be greatly appreciated.

 

[The_Roadie]

Welcome!

The rear tires can move in and out 1/4" or so just because of the design of how the axle shafts are retained by clips inside the differential. That's not a problem unless you mean looseness in another way. The axle is held from moving left/right by the Panhard bar. Make sure its mounts and the four rear control arms are tight.

Assuming you don't have anything else loose in the front, such as upper or lower control arm bolts, it may be just needing an alignment. What happens if the toe-in isn't in spec, is that any side to side change in weight on the tires allows the vehicle to track more where that side tire is aimed. When the toe-in is incorrect, those will be slightly different directions, and even bumps in the road can have that effect. The alignment tech will also look for other loose items that will make it not hold to specs.

Also, how many miles do you have, and do you know its maintenance history? Typically, what you want to do to a new vehicle is not trust ANYTHING said by the salesperson, or the previous owner if they're acting like the salesperson. Change EVERY SINGLE fluid - including transfer case (which is a surprisingly short 50K interval), brake fluid, tranny coolant, power steering fluid, engine oil, and both differentials. Check 4WD functionality not just be observing the lights on the switch but listen closely to the two motor sounds underneath when it changes modes and functionally on a patch of sand or gravel.

 

[white02tb]

The truck was bought at auction at the dealership I work at, so I bought it. I have changed the oil, the front diff was almost empty (needs axle seal - doing that this weekend) also going to do the trans and rear end fluid. it has about 130,000 miles on it. The 4wd works good I think the switch might be faulty because it goes into 4HI randomly (so far like 6x in a month). im just concerned about the sway under acceleration and deceleration. I will have to get an alignment in the next few days to see how what that corrects for ride.

 

[tblazerdude]

2nd the alignment (it will at least identify worn front suspension parts). Make sure you get a print out, more and more alignment shops just toe adjust and let it leave.