850 darts under heavy throttle

Post by **matthew1** » 03 Mar 2010, 19:08

Hi guys, I have something I don't know where to go with from here.

About 6 months ago I noticed a tendency to dart left or right or both quickly under acceleration. If the pavement is grooved from semi truck wear, the movement left/right under throttle can be significant

. I know it's not torque steer. I've had the car 10 years now and know her inside and out. While torque steer has always been there and still is, this isn't it.

It's become more pronounced, and today I had the car up on the jack to test the front wheels for loose behavior when moved side-to-side. Nothing. It was tight.

thx
Matt

volvee850glt · Post by **volvee850glt** » 03 Mar 2010, 19:31

That has been happening with mine too. I never really thought about though.

Post by **jblackburn** » 03 Mar 2010, 20:19

Take a look at your control arm ball joints/bushings. If they're loose or deteriorated, it'll make it dart around under power.

Post by **boosted5cyl** » 04 Mar 2010, 06:45

How long has it been since control arms and other suspension parts have been replaced? Often you wont notice any play when you pull it by hand, especially on rubber bushings, but as soon as you take it on the road.

If all of the suspension parts are known-good, (control arms, tie rod ends inner and outer, ball joints, sway bar links and bushings etc etc) then it might be worth getting the alignment checked out as toe out will also cause the front end to dart around and it wont neccacarily pull to one side either.

Post by **matthew1** » 04 Mar 2010, 14:02

All original suspension parts. 98k miles.

Post by **jblackburn** » 04 Mar 2010, 14:13

Matt, look for something like this:

That's from a Honda, but all are similar. You may not notice any looseness when tugging on it, but when all that 3000+ lbs of Swedish lead gets put back down on the suspension, the old bushings will push apart again. It is pretty easy to cut or push out the old ones and a bit harder to push in the new ones.

Usually tie rods will only fail on one side at a time, and cause it to pull in that direction all the time, but it's worth tugging on them and seeing if you can twist either of them around. The same goes for the sway bar links and bushings, you will probably hear clunking or excessive body lean in corners when they start to go. You're probably coming up on the point where a lot of suspension components are starting to wear out or could use replacement.

Post by **matthew1** » 07 Mar 2010, 20:57

Thanks guys. I took some pics, and yes it looks like the control arm bushing is shot.

I'll take the wheel off again soon and inspect closer.

: front-right-850.jpg (337.22 KiB) Viewed 1890 times

Post by **RobTheModd** » 08 Mar 2010, 12:23

I had same problem untill I got my control arm replaced.
Havent noticed the problem at all. and I tend to gun it alot.

Post by **matthew1** » 20 Apr 2010, 22:28

Justin, can I replace only the bushing?

Post by **jblackburn** » 20 Apr 2010, 22:36

Yep! There's no need to replace the whole thing unless the arm's bent or the ball joints are shot.