need suspension advice!

[deadflo]

My "new" 71 Z has some problems with handling. Im not sure how old the shocks springs or bushings are but heres some symtoms of the problem.

The car has a real tendency to "bottom" out on undulating road surfaces. The bottoming occurs in ther rear and I'm referring to a "squonshing " noise on hitting bumps. The noise happens more often when i have more weight in the back, like when the gas tank is full.

More problematic is when I hit rough patches of road with the rear suspension. especially on the right rear, the car will "jump" a bit sideways. Yesterday on a tght corner at only about 35 MPH the rear hit a bump and really lost it sideways.

Ok the car has both front and rear swaybars, both have good poly bushings. I couldn't really see obviously badly deteriorated bushings, but im not an expert.

Many of the suspension parts are painted..the springs and sway bars have been painted yellow. Would this indiavte how old they are? I think they are lowering springs because my tire and wheel combo really fill the wheelwell.

Im wondering if the springs are sagging, Ive heard if they're too stiff they can cause handling problems on rough roads and thats certainly the case.

I like to get away with just changing the shocks, but maybe i need springs too?

[240ZX]

The most likely cause of the poor handling is the 30+ years old rubber bushings. Specifically.......all of them. Replace ALL of them with urethane units....each and every last one of them and follow the directions!!! Regarding the springs.....what do you want the car to do? Street cush, moderate cornering, maximum street performance, or track/auto-X? Replacement springs are available for just about all applications, even if you decide to go with coilover kits. So, if the car bottoms out too easy, in your opinion, you need stiffer springs. Get yourself a decent set of strut inserts (shocks) at all four corners as well. Hope this helps a little!

[ZmeFly]

Most of the sloppy handling does come in the fact of olllllllllllllld rubber.

For a great price on a complete set of urethane bushings if that is the route that you will choose go to www.suspension.com, talk to Bruce, great guy.

Also depending on how you drive and what you will be doing with your car is indicative of the suspension set up you choose. Me personally I dont mind a lil bit of a rough ride to get good handling.

Ive always went with and been happy with SST springs and Tockico struts. MY ZXT that I have now has a complete Tokico set up less the sway bars. I must say Im pretty impressed with theyre springs as well.

Good luck with whatever you decide

[deadflo]

I dont mind that stiff of ride, but the current problem is really the odd inability of the suspension to deal with rough roads where handling is concerned.

The handling is poor because the rear end is "losing it"..literally mving sidways at speed when you hit rough patches of roads.

Do you think the reaction to rough roads would be caused primarily by the bushings versus the shocks or springs?

I've seen another link that mentioned too stiff of a rear end from a large rear sway bar, I'm wondering if the aftermarket bar on my car could contribute to that?

I'd like to fit the Tockico spring and strut package, but wonder if I should just start with bushings first.

[1975yellowBSPZ]

If you suspect the rear bar is too stiff, pull it off, and replicate the issue. If the symtoms are unchanged or aggrivated it is most likely bushing, struts, or both. If it settles down with out the rear bar, go for a smaller bar or none at all.

Replacing the bushings and struts is a good idea any way though.

Bw

[44014]

hey i had this exact probem with my 73 240 while your bushes and every thing are'not helping your problem here is your shocks causing it to jump sideways and bottom out all the time from no compression damping my zed would try to go side ways just going over exspansion joints on a bridge definetly the first thing you should look at

[44014]

oh and i fixed it too i fitted 350 pi king springs and adjustable konis and replaced every bush with uerathane $4500 later problem solvered

[drunkenmaster]

I have heard its best to use rubber in the rear.

Urethane in the front is nice for the steering?