Hi

I have been working on my rear suspension and have noticed a change for the worse in only a few miles of street driving. To best describe it the upper and lower edges of the open ends of my trailing arms where the spring bolts come through are starting to look like slightly used chewing gum.

They are fresh rebuilds and last year they were fine and only have a couple hundred miles on them (including one "dyno day") since then. A guy working on the car suggest I have been beating on my car but that is not true. The car has been mostly sitting for the last year while waiting for a new motor to be done and when I have taken it I have not been either hard shifting or cornering it.

It has a 7 leaf spring that seems very stout in comparison to the fiberglass spring I used to have before a restoration was done and the new trailing arms were installed 2 years ago. Last year a guy working on the car (same one as now) said the resto shop had left things to loose and he tightened them so I cannot help but wonder were they over torqued? The bolts are the correct length (although I am now installing longer ones for the dragvette strut modification)

Could of this been caused by a wrong combination of spring, shocks and sway bar? It does have a "bouncy" ride and the next planned changes include a change back to a glass spring

They can be straightened in place however the metal has already been weakened. I was wondering if any of you who know suspensions have a long term prognosis or any explanation as to why it happened in the first place.

Thanks in advance

Doug

 

Are these the original trailing arms to the car?

Any chance of posting pictures of each arm end and rear end setup?

Andy

Just looked at your bio, 625 HP.... sounds pretty torquey ( Is there such a word? ) and lots of FUN !!!

 

Hi Andy

These arms were purchased already assembled in 04 from a place in Pennsylvania that is both well known and considered by all whom I have talked to to be very reputable. Come to think of it I should give him a call and ask him what he thinks.

I tried to take some pictures yesterday with a built in flash but they did not come out. By the time I get back there tomorrow the gentleman working on it will probably have the second (drivers side)one straightened out too. He straightened the passengers side while I was there by inserting what looks like a wedge that expands hydraulically into the open end.

Chances are I will not have any pictures to post. However if you can imagine putting a stick of stale gum lengthwise along your jaw-line and between your teeth and biting down on it is about the best I can do to describe it.

Doug

 

Doesn't look something like this does it?




A previous repair to the other side was done in this fashion before I purchased the car.



These also are on my "To Do List"

Please keep us posted. I'm uncertain which is best: Buy bare ta or compete rebuilt.

What condition is the snubber bumper, if the spring bolt pulls through or the spring breaks, this will absorb "some" of the impact. If you look closely you will notice mine is gone. Also on my "To Do List"!


Andy

 

Hi again Andy

Your fatigue is quit different from mine in regards to location and type. Mine is primarily (90%) on the upper horizontal and is then collapsing inward instead of on the bottom and going upwards as yours does,

Maybe I (we) should consider looking for answers for this problem in the autocross section of the forum. There are some old time racers in this section but it has been a while since they have been gauging suspensions.

The good news is the damage is really just in the looks since it will still function as it should. I would take a guess that with mine it has a lot to do with the heavy duty metal spring and large sway bar. I used to jam my car pretty hard and I always thought oversteer was just another way around a corner. However I had adjustable shocks and a glass spring in those days. There was a little squat when shifting hard but there was not any bounce like there is now. I thinking that next year I am going to switch back to a similar setup (but fully adjustable) and maybe a front mono spring too.

If I hear from someone whom I consider qualified to render an opinion I will pass it on to you.

Thanks for your replies

Doug

 

Doug
I have a 66 BB roadster with a F-41 suspension (7 leaf spring and heavy duty rear Swaybar). I autocrossed this car for a number of years. The rear suspension is orignal and shows no damage. I do not believe the cause is the suspension or the fact or how it was driven.

The pictures Andy sent look as if some shade tree mechanic has attempted to re-enforce the control arms mounting points I have never seen anything like this done before. I can understand why and how someone would attempt to do the job this way and think it might be good idea if done professionally. When I restored mine, we had to repair the frame infront of the rear wheels, where the two frames come together, and I dare someone to tell the work was done. I had a very good man do the work.

Are there any cracks in the metal? It would be good to know what your mechanic "tightened up"? Does the damage show where the spring mounts or where the swaybar mounts. If the spring has all of the washers and rubber mount then there should be no damage. If the swaybar is not mounted with the correct linkage then maybe that would damage the top mounting bracket. Without some additional information, there is no way to tell what may have caused the issue.

By the way, mine is a 66 and lived in Northern Virginia for most of its life. Therefore it had the humidity and rust to fight but was never driven when there were snow and ice chemical on the road. It could just be "old age" but I doubt it. The car suffered some abuse sometime during its life. Someone tried to jackleg the suspension and did not do a good job.

 

Hi a66bbvet

Thank you for your reply

My damage is at the sway bar end and I am going to get back with you on what all my friend did last year when he did the "tightening up".

I can tell you that at that time he did point out some things that were loose such as the later model alignment spacers that did not have the cotter pin yet could be moved by pushing with just one finger. One other thing was the driver side rear wheel has also shifted and gone from being perfectly vertical to being angled in at the bottom. However the struts are new just like everything else so that did not happen because of them. There were some other things like wrong bolts for the upper shock mounts and no spacer for the transmission but I do not consider those things to be relative

I will be working on the car tomorrow afternoon so I will get a chance to check on how he says the sway bar linkage appeared before he disconnected it. Tomorrow night I will post that and any thing else I think might be relative

Thanks again for the reply and I appreciate the help

Doug

 

Doug
You do realize there is a cam at the end of the strut arms that controls the tilt of the wheel (I always get it wrong but I think that is called castor not camber). Bottom line, if your rear tire tilts in then you need to loosen that strut arm and rotate the cam and get your wheel more in alignment. If you have the rearend aligned then they should take care of that for you. I am not sure what you mean by the "later model alignment spacers.

If you can provide some pictures that show the problems, we may be able to provide some further help. When I raced my car, I use to spend many hours working in this area. There are many little known secrets that deal with this part of your suspension.

Vic

 

Hi Vic

Your ears must of been burning LOL

I just got in and was looking through the VBP online catalog when the in box lit up. First what I believe is a significant contributor to the problem is that for some reason the rear bushing for the sway bar on the passenger side is way to big. Consequently there is a lot of movement in the bar and that combined with the original style linkage is probably the culprit.

There is 30% sale coming up at VBP so I am going to switch back to a composite spring and have them throw in some new 5/8 bushings that will hopefully take care of the bar movement. I would like to add one their new tubular bars with the VBP style of linkage but that would be hitting Peter and Paul both at the same time if you know what I mean.

I just came home to use the computer and am going to head back to the car now so I will chat with you later

Doug

PS BTW I an installing the new struts from dragvette and will be getting everything close enough to be able to drive to the alignment man. "New style spacers" are the C-3 ones with open ends consequently they should have a cotter pin.