Bouncing New Suspension

Cmino · Posted: Thu Feb 08, 2007 10:35 pm Post subject: Bouncing New Suspension

Frustrating front end bounce on my '87 Chevy El Camino with the following new parts just installed:

- Bilstein shocks P/N F4-B36-0949-HD
- Eibach Pro Kit 1" lowering springs
- Tubular upper control arms from Speedway Motors
- Bushings and ball joints for upper & lower control arms

The Camino wiggles and bounces like jello when pushing on front end when truck is parked. Rides like those little ricers without shocks. Suspension worked ok before replacement but it was time.

I forgot to hold the piston rod when attempting to snug one of the shocks and turned the rod w/self-locking nut 12-15 times but held it in place when tightening until rubber bushing was pressed to the same diameter as the mounting washer. It's hard to believe but could I have still damaged the shock?

The whole suspension and steering replacement was simple and I just can't figure out what I could have done wrong.

Any suggestions are appreciated.

ghotachevy · Posted: Thu Feb 08, 2007 11:37 pm Post subject:

did u tighten the bolts on bushings with the weight of car on them

Pack Rat · Posted: Fri Feb 09, 2007 10:59 am Post subject:

Are the shocks you installed consistent with the 1" drop springs?

Cmino · Posted: Sat Feb 10, 2007 12:18 pm Post subject:

Weight of truck used only for shock tighteningl but tires were off for all ball joints, tie rods, idler arm, and drag link installs. I didn't think it was an issue. I believe when you are tightening the nut to torque you are just wedging the cone shaped ball joint stud into the spindle mount hole. I figured the weight of the truck forcing the stud into mounting hole would assist getting to torque quicker but the torque would be the same either way. Bottom line, as long as it's not loose, it should be fine.

My research did not turn up any problems with these Bilstein shocks used with 1" drop.

ElkyPete · Posted: Sat Feb 10, 2007 1:03 pm Post subject:

I'd say if you have that type of bounce, those shocks are no good, not for your application anyway. It's not going to be most any of the rest of the parts, well possibly the spring rate and the shocks in combination. But mostly it's the shock that are suppose to dampen the bounce to even the ride out.

Can you adjust those shocks? I know some, like the QA1s, are suppose to be adjustable rate. Some aren't.

Do you have a Big Block? Or extra weight on the front end now?
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Pack Rat · Posted: Sat Feb 10, 2007 1:10 pm Post subject:

Looking on the Bilstein shocks web site those shocks are not marked as be right for drop spring applications.

Just FYI

Cmino · Posted: Sun Feb 11, 2007 3:15 pm Post subject:

The truck still has the tired original V8 engine so no extra weight. I don't believe these shocks are adjustable.

Pack Rat, I agree, the part number needs to end with a '+' sign as recommended for use with shorter springs. The Bilstein web site doesn't list a specific shock for lowering G bodies. They possibly have spring/shock kit with their PSS model but I already had the springs and just needed the shocks.

Eibach indicates no shock change needed for 1" drop springs and figuring worn springs drop the vehicle anyway, stock shocks must have enough travel to compensate for worn springs, so I thought these shocks would work fine. In fact, since I started cruising in 1976, I've never heard of the need to modify shocks for this type of minor drop.

It does appear though the shock is the problem and would then also be an issue for the rear suspension if lowered. Which brings up another problem I ran into last night. The Eibach drop spring is the same physical height as the spring I took out and the spring rate must be identical because the truck did not drop at all in the rear. So only the front is dropped. Nice rake though.

I guess I lost my knack for playing with my vehicles because I researched and still screwed up. Wrong shocks and springs adds up to a terrific waste of money and time. As a side note, I would also prefer a tubular control arm with a cross bar with bumper mount to eliminate stress on ball joints when raising the truck. Still great for the price though.

While I'm waiting to hear back from the Bilstein product specialist at RCD Classics, I'll put the old shocks back in for comparison.

Thanks guys.

Pack Rat · Posted: Mon Feb 12, 2007 4:20 am Post subject:

Well not that you don’t have enough to think about on this project, are the springs progressive weight or no. I don’t in anyway claim to be an expert on Elcaminos I have just gone through a lot of parts hunting because 80-90 % of sales people out there think that will it looks like a Chevelle so the parts must be the same on both (NOT). This is some what true from the doors forward and NOT from the doors back, think station wagon and you will save a lot of time hunting parts.

again just FYI

Cmino · Posted: Mon Feb 12, 2007 4:35 pm Post subject:

The Springs are progressive.

Pack Rat · Posted: Mon Feb 12, 2007 5:03 pm Post subject:

Think shocks, I do believe that is the problem.

CANTED · Posted: Mon Feb 12, 2007 7:45 pm Post subject: suspension

What ghotachevy said about tightening with it under load was refering to control arm bushings. It makes no difference with the parts you mentioned but will on a standard type control arm bushing. When you tighten the bolt with the arms hanging, the bushing is trying to twist when the car is lowered. This does not apply to a bushing that has a center that turns like most poly bushings.
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savrenovations · Posted: Mon Feb 12, 2007 7:50 pm Post subject:

I used the same spring kit that you did. The drop worked very well for me it was about 1"-1 3/16" all the way around. I installed some cheap KYB shocks as well. I also installed a 1 3/8" front/1" rear sway bar. I was thourougly happy with the results! A week or 2 later I installed the Air-Lift 1000 air spring kit and was even happier!

I would have to concur...must be the springs...but I do not know why as the springs I installed were not specific to any drop.
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Cmino · Posted: Mon Feb 12, 2007 10:29 pm Post subject:

Very possible that tightening the control arm bushings without vehicle weight is playing at least some part in this. When I replaced the rear springs and disconnected the upper control arms from the differential, there was definite spring action in those arms since I didn't loosen the other end.

As soon as time allows I'll first redo the C.A. bushing bolts with truck weight. Then try the old shocks if still a problem. Both are quick but I just don't get to play as much as I use to.

I still need to look into the rear springs with Eibach.

Cmino · Posted: Wed Feb 21, 2007 8:12 pm Post subject:

Well I loosened the C.A. pivot bolts, bounced the Cmino a few times, then re-tightened. It helped but only slightly. Then I put the old shocks back on and it helped a little more but truck still bounces & jiggles way to much. I put the new Bilstein's back on and loosened/retightened the stailizer bars but didn't help. I called Bisltein but could not talk to anyone that actually knows the tech of their products. The "product specialists" that Bilstein lists on their website that I've been contacting since the 8th apparently can't get info from Bilstein either and doesn't have an idea from experience so I'm getting nowhere.

The best I can figure is that the springs are too much for the shocks - at least at little or no shock travel (typical small road bups) which is when the truck is really "loose". When really using the shocks like over speed bumps, they dampen fine but the trucks has small bounces as it settles.

Pack Rat · Posted: Wed Feb 21, 2007 9:34 pm Post subject:

How much of the shock rod is showing in the normal setting position?

Most shocks operate with at least 1/3 of the rod showing witch puts the piston in the right place to operate correctly.

I do believe that the shocks are the problem, the small bumps at the end is the shock trying to center them selves and can't.

I think from what you have been saying that the shocks are to long.