Rumble, Rumble, Smack, Smack - New Shocks?

[cats935]

First, as a newbie, let me say you guys have a great forum. Definitely did some searching before posting, and though some topics were somewhat on point, it didn't get to exactly my issues.

I'm runnin' in a 2003 QX4 with 78K miles and original struts/shocks and basically all original suspension. Generally alright ride in the past, but started getting cabin shaking (like I was going over a million little bumps all perfectly lined up and spaced apart) between 45-65 mph about a year ago. Below 45 and above 65 everything was relatively smooth. Got new tires about 10K miles ago (Michelin Cross Terrain) and that seemed to quiet the shaking for a while. Also got new brakes and rotors about 3K miles ago, but that was a different issue altogether.

I recently had the tires rotated and balanced, and let me tell you, as soon as I pulled out of the shop and got on the highway, that da*m shaking at about 55-65 mph was back with a bigger vengeance than before - like I'm on a frikin roller coaster ride. That shaking made me realize how rough the ride is when I hit a pothole or sharp bump (I feel the smack in the back of my spine and it feels like the dashboard is about to crack in half), or how the truck hops and rolls almost into the next lane when I hit a bump on a curve.

So, here's the stupid question: is it time for a new pair of struts/shocks or is something else going on? If I'm gonna throw $600-700 at new struts/shocks, I'd like to think that the rumble, smack ride will be no longer. I'd hate to spend that money, only to find out that the problem is elsewhere, and that it would've been a much cheaper fix and I just blew $700 on something that wasnt yet needed.

If I need new struts/shocks, the follow-up question is should I also replace the mounts (it sounds like some people call them bearings, but I'm guessing everyone is talking about the same thing, right?) on both the front struts and rear shocks.

Thanks in advance

[Chuck Tribolet]

If a rotation and balance made it that much worse, TAKE IT BACK.

[K03sport]

well, new shocks/struts can't hurt. They don't last forever and are due for a change at some point in time.

You should be able to install the rear shocks yourself. It should be two nuts and your done. The front is probably a bit more involved, but still can be accomplished by yourself with jackstands, and a spring compressor. A spring compressor can be rented or loaned from the parts store you buy your stuff from.

Remember to only do one side at a time, that way you have the other side as a reference.

A Haynes manual should give you enough information and still be cheaper than one hour of shop labor.

[cats935]

Thanks guys; what's a good general rule of thumb for when struts/shocks should be changed? KYB says every 50K miles (obviously; they need to sell their product), some guys say 100K, others say longer.

If my car is bouncing along the road and around curves, while eating potholes and bumps like a third rate boxer, is it time? Or should I be going down the list of other cheaper fixes first? Also, what about the mounts and bearings? Are they the same thing or different and should I be getting new ones as well when I get new struts/shocks?

[NewX4]

I have an '03 QX4 and had to change my rear shocks at about 60K. We also bottom out with any rear-end weight, so the rear suspension gets a beating often.

As you read more posts, you will see our trucks have short travel, hence crappy OEM suspension for a truck.

I agree with the previous post, and I would see if a (free) re-alignment would help.

Good Luck!

[hospitalbuilder]

I have a 99Q so things may be different, but you should consider re-packing your front wheel bearings. Particularly if you have had the front wheels under water. Although, if you replaced the rotors in the front, they likely did this since you have to remove the rotor to get to the bearings. Did the ride differ any from before to after that service? This is heavy on labor, light on materials.

Here is a good walk through for an Xterra, but it worked well for me.

http://rkrenn.com/xterra/howto/bearing/bearing.htm

Beyond that, I had a shaking problem in my Q which was remedied when I replaced the front struts (done at about 170K, replaced the originals I believe). I really noticed the shaking/bouncing on the interstate when I would hit any bump at all (which in Denver there are many). Changing the front struts is a bit of a wrestling match, but doable. The rears are quite easy, in fact our local Pep Boys often offers free installation with purchase.

Anyway, good luck to you and let us know what works.

[QXFo]

Any luck with the bouncing wheel? I swear you described exactly what my 99qx4 has been doing. I have also changed tire, balancing, alignment... everything but struts, which is currently in the works. If you got it fixed please post and let me know what the problem was! It's scary as hell making a turn and hitting a bump at 65. HOLD ON FOR DEAR LIFE.