Front end rattle - finally gone

[Beav]

Had a few moments this afternoon to fiddle with the car. Some time ago I had torqued the suspension bolts to spec (imagine that - me using a torque wrench on my own car!), but with only minor success. As I began thinking about it I realized that the length of the bolts going through the cradle and control arm bushings are fairly long. What has happened is because of their length, time and vibration has allowed them to stretch, loosen and create small wear marks where the bushing ends sit. Torquing them may have worked years ago when the marks were smaller, but today the marks are larger and the bushing ends probably aren't going to be sitting in the best spot for factory torque specs to work properly.

So, grabbing my trusty impact wrench, I wailed on the bolts and could see as they tightened they had some torsional give to them. Now some flexing is normal, but my experience is that the twist was a tad over the top. Anyway, using my trigger-finger torque measuring device, the bolts are now very tight and all noises are gone. Not that the car was ever a rattle-trap, it just wasn't as quiet as it should have been. Now if I replace the two rear strut mounts it should be dead silent.

For those that like to DIY, be careful if you go to over-tighten the bolts. It takes an experienced touch to know when to quit before breaking a bolt and I've broken my share in the past. If you break one of these bolts it will really, really suck to replace it.

[mbtoloczko]

Hi Beav,

Could you be a little more specific as to which nuts/bolts you wailed on? I've been tearing into my suspension since I got the car, so I'm curious as to which nuts/bolts you are referring to. Thanks. :-)

[James Scott]

I did my Ferrari suspension last summer, including all control arm bushings (pressed and mig or tig welded), ball joints, tie rod ends and Koni (stock) shocks. Although these items were not horrible, each was worn enough that when I got done there was a totally quieter and tighter ride to the car. [BTW, I also snapped my wire and put on a very expensive (Tubi) polished stainless steel exhaust. It's loud, but has about 10+ more horses.]

At any rate, I was wondering if you preloaded the suspension before tightening control arm bushings, like I had to do on the Ferrari?

[Beav]

I didn't release the tension on the bolts before tightening them, so I didn't feel that centering them first was a concern. Plus I knew that they were 'spec' tight, and as such they should already be in their proper positions. For those that don't know, control arm bushings, strut rod bushings (on cars so equipped), etc. are torsilastic, meaning that there is a steel sleeve inside a rubber busing that is inside an outer shell. When the arem pivots the rubber flexes but doesn't spin. If the bushing is tightened down while the wheels are hanging the bushings will soon be ripped as they are operating beyond their centered positions. Whenever these bushings are loosened or replaced the vehicle needs to sitting at ride height (preferrably on the ground) before tightening them.

I tightened every bolt that attached control arms and suspension cradles to the body.

[svx_commuter]

Sometimes I do really dumb things and I will share with you all another dumb thing I did. I tightened the bolts between the sub-frame and the body to the point where the body nuts stripped out. The bolts use fine threads in the welded body nuts. Over tightening will pull the threads out of the body. 1/2" breaker bar and 4' pipe mistake. I replaced the bolts with larger diameter ones after retapping the holes.

[Beav]

Yup. Like I said, it will suck if you break one off.

[Chicane]

Could you do this with hand tools? And make sure it's on the ground eh? My car sounds like a truck.

- Rob

[svx_commuter]

I tightened mine up yesterday night.
Jacked up the car, took off the wheel, placed a 6x6, 2x6, 1x6 under the ball joint bolts under the control arm. The wood was long enough to reach the sub frame. Let the car down onto the wood so that it supported the control arm and the subframe. This looks close to the mid span of travel. Backed out one of the control arm bolts about an inch. I wasn't brave enough to take it all the way out but I think I could have. It was turning pretty easy. The bolt was shinny and this turned out to be oil. Most likely from my recent oil leaks.

I used double wrench to get some leverage or a 1/2"bb and tightened the control arm bolts, two on each wheel. To my surprise all the bolts moved about a 1/2 turn.

This morning while riding TO rt 80 over country roads everything was quite. Sounded great and felt great.
Drove 47 miles down the rough road, rt80, this road is a very rough. Got off rt 80 and drove 2 miles on the city streets and and and and the noise is back.

[Beav]

If you don't loosen them you won't have to worry about centering them before tightening (unless the bolt is ready to fall out. )

John, try tightening them one more time - they may have just found the bottom of their worn spot. Also try tightening the bolts that mount the cradle to the body, I suspect that was where the bulk of my noise was coming from.

[svx_commuter]

Beav,

Thnaks, I will try to tighten many more times if I have to.

Is it possible the rubber bushing is harder, not as flexible as when new, and now the twisting motion of the arm is not absorbed by the bushing? Maybe all the twist is transfered to the inner sleeve with the harder rubber. Can that inner bushing sleeve hold the full twisting motion of the control arm travel? The fact that oil is all over the inner sleeve is not good. This will just let the inner bushing slip/roate easier. I wish there was some way to put some teeth on the inner bushing face that contacts the subframe.

Do you think the rubber between the subframe and body can wear out?