Hi Guys ,

i need someone to offer a bit of advise regarding the steering / control arm set up .

I have replaced all the ball joints on the front , the idler arm , bushes , in fact all of the front suspension with the exception of the upper and lower control arms , new springs as well .

When i eventually got my steering column finished and was checking the turns from lock to lock there was a very slight difference from full left to full right in that the left full turn was approximately 2 and a half full turns,but the right side was about 2 and almost three quarters turn . I checked the full system and the box i rebuilt as per Jim Shea's instructions is set up correctly .

When i checked underneath the vehicle the lower control arms have a locating stop welded to them which is shaped to take the stub axle when it is turned to full lock . This is where i think i have the slight difference in the turns between centre to lock .

The stub axle section that should locate in the scollop of the stop is hitting the lower control arm edge and not going into the stop . ie the stub seems lower than control arm , slightly !!

Do you think this is due to the stiffness of the new springs , there does not appear to be anyway that these arms can be lowered at all without spacers or something . The suspension was all re-assembled as per the AIM , i also do not find any reference in the AIM on the bump stops welded to the lower control arms .

Point me in the right direction guys !! the suspension is even on both sides , car had not been driven in the last 4 years while i have been busy trying to rebuild the car ( not body off ) i dont have the space to tackle that type of restoration .

Thanks guys ,

John

 

springs seated?

 

Hi ,
Thanks for the fast response .

Once I got home I jacked up the vette and had a quick look over my spring installation and the lower section of the spring is a small fraction away from where it meets the shoulder of the lower control arm . The top is difficult to see and it might be possible that the top coil is a fraction long but I can't really say unless I drop the spring out again and look for e marks where it has been sitting , the lower section is easy to see gm put a nice inspection hole so you can see the end of the spring .

I must tel you though tha springs were fabricated for me by a manufacturer here in south Africa , so I am not altogether sure if he made them the exact length as the originals . Could they be too long ? I can't remember struggling to get them installed ,, but if I look at the difference of the stub axle point and the locating area of the bump stop it must be about 10 -15 mm off ie hitting the lower control arm instead of locating into the bump stops .

Guess I have to go through all the pita again and strip and check what the guys who made the springs have done

Thanks again

John

 

There is an inspection hole in the top spring pocket. The end of the spring should cover ~1/2 of the inspection hole. Since these are not stock springs I wouldn't worry about where the lower end of the spring sits in the lower pocket. If the upper spring positions aren't correct, dissassemble and line them up.



Rick B.

 

Hi Rick ,

Thanks for the advise , i saw the hole in the lower arm and the spring looks in exactly the correct position , the top hole i couldnt pick up but i will look again later today . when i shone a torch up from underneath i could see the spring end and it does look as if its set in the pocket with the end of the spring almost at the location point , but its hard to see properly .

Guess i will have to break the lower ball joint again and see if i can lower the arm and get a bit of twist on the spring or remove it all over again . I did ask the spring manufacturer to keep the lengths the same but to tighten the tension up a bit , after all the originals were 30 years old and i figured that they would be less than effective . Not sure if he used the same thickness material in manufacture , tightened and added an extra coil or what , but i am not happy with the set up as it is . i will strip it and make sure its correct before it goes back on the road .

Thanks a stack Rick you have put me on the right track .



John

 

I happened to have a pic of the upper inspection hole. It is visible from the top if you look down between the shock tower and the upper control arm. You can see the end of the spring covering 1/2 of the inspection hole.
I just remembered what that blurry thing is at the top of the pic. It's a flashlight.



Rick B.

 

Hi Rick,

Thanks a stack for your help with this problem .

I stripped out the suspension again and had another look , made sure the upper end of the spring was as you said covering half of the hole . Found the best way was to paint the end of the spring white and then you can see it more clearly , but after everything it still not right the stop of the arm is still sitting too low and only hitting the control arm edge .

I am concerned with the final tightened position of the top ball joint . These are also new but i am concerned that the stub axle top section is not going far enough up on the taper of the joint . There is a visible gap between the arm and the dust cover , ie when the arm is fully tightened the dust cover is not even compressed a fraction unlike the top ball joint on my 73 vette which has the dust cover compressed slightly and a fair amount of the ball joints thread protruding below the nut .

I am sure if the top piece of the arm went further on the ball joint taper the complete arm would be higher. the measurements of my axle correspond with what i have on the 73 vette .Unfortunately i threw away the old ball joints when i got the new ones so i dont have them as a reference . If it has to come to it i will fit the stub axle from the 80 onto the other vette and see if the problem is the same if fitted onto some old ball joints .

Thanks again for taking time out to assist , let me know what you think about the ball joint theory .


john

 

If you could post some pics that would be very helpful. Is there any corrosion on the inner part of the joint that could cause the ball joint spindle to not seat correctly? You could try sending a PM to Jim Shea. It's entirely possible that the difference in turning between right and left is normal for the design but Jim would probably know for sure.



Rick B.

 

We have communicated on this subject. I mentioned that the slight difference in right to left full lock turns could be within the margin of tolerance for the entire steering system. The flat on the gear input shaft (at 12 o'clock) should still dictate the gear being on-center.

However, this does not explain the lower control arm stops not hitting the steering knuckles equally and in the same relative locations. This can easily explain the differences in gear travel right to left. It would seem to me that possibly there may have been collision damage in the past that has gone unnoticed or uncorrected.

The location and relationship of the steering stops and knuckles should remain the same regardless if there are spring differences or if the spring(s) are seated correctly or not. Differences in the lower ball joint seating could affect the relationship of lower control arm to knuckle.

Jim

 

Hi Jim ,

Good to hear from you again .

i must say this one has got me a bit puzzled , but i will get there eventually

I agree that there should be very little bearing on the spring theory , not saying the guys are incorrect , the spring must be seated correctly otherwise the lower arm would push down lower . The relationship and the dimensions that remain unchangeable are the top and bottom of the stub axle , ie where the ball joints locate . If the top cannot go far enough into the ball joint taper then the complete stub axle is forced lower which would give the issue i have now , the lower arm with the cast location nib does not locate into the bump stop bracket , instead it hits the lower control arm edge .

I have checked the set up on my 73 and the only visible difference i can see is the top ball joints . The stub axle on the 73 definitely goes higher into the ball joint taper and the dust cover is compressed slightly , whereas on the 80 there is no compression of the dust seal , i can see some of the taper still and the castle nut does not use as much of the thread as on the 73 .

I may be leading people away from the problem by stating this , but i do know that there is something not right and i wont drive my vette like this . All the joints are new and i dont think others would really be too concerned as it does not affect anything on the steering of the vehicle except that the lower control arm is acting as the bump stop .

I can see no repair damage on the car , in fact it looks very original and if it was or has been repaired before i would have seen or expected differences from side to side , but both arms are positioned exactly the same .

Looks like i am going to have to take off the stub axle on the 73 and see if the one off the 80 fits onto the 73 and where the lower arm ends up . If its all ok on the 73 then i know the problem lays with the control arms and or ball joints and springs on the 80 . These are the only items , oh and all the bushes that have been changed .

I will see if i can get my i pad to take some pictures and let you guys have a look , so i am not giving you all false leads , you may see i have assembled something fundamentally wrong , but i have checked and re-checked and checked again .

Thanks a stack guys , back under the car tonight i guess

John

 

Hi Guys,

Back again . i have taken a couple of snaps of the top ball joint i am not altogether happy with , but i think given the majority of advice i have received seems to advise me to look in the direction of the springs , and because my head tells me that these are the only items that were not made in the USA , i am going to tear down all the suspension again tonight and double check .

Does anyone have a measurement for the spring length , my set up was originally a gymkana suspension according to the build sheet , or what was left of it that i took off the petrol tank .

Thanks guys lets hope i come up with a few answers after tonight



John

 

http://forums.corvetteforum.com/c3-t...+spring+height

 

Hi ,

Thanks a stack that's brilliant , i will check the length tonight , looks like its about 13 inch long from what i see on the one picture with the tape measure .

If mine are a lot higher would you recommend i cut them ? or take them back to the manufacturer and let him compress them more and retain the amount of coils ? I can hardly push the front end down as it is . I could cut them myself to say 14 inch and hope that with some use they will relax to the correct height, what do you think ??

John

 

cutting the springs wont fix your original issue , but it will lower your car, why dont you cut your original springs if needed and take those back.

 

[Hi ,

Do you feel like a working holiday ?? Weather is good lots of beer and some braai's

This one really is irritating to a point where you start losing your mind . I dont have the springs that came off the car , i gave them to the guys who made up the new ones as a sample and never thought about asking for them back .

i have had these springs for over 18 months and never thought anything of the ride height of the car or the bump stops when i put it all together and it was only once i replaced the turn signal switch i checked the lock to lock turns and noticed the bump stops were not corresponding with the connecting arm , also i have only just installed the motor and tranny so i am only checking all the cars finished ride heights now .

The front is hell of a high ie the gap between the tyre and the wheel well is over 100mm about 4 inches , so i was wondering if the springs were the route cause . whatever the problem is , its an even problem as its exactly the same from side to side .



John



QUOTE=oldalaskaman;1582148642]cutting the springs wont fix your original issue , but it will lower your car, why dont you cut your original springs if needed and take those back.[/QUOTE]

 

To make sure everything is centered, measure the length of each tie rod. The left and right should be identical.
To make them the same, and maintain the correct toe spec, I disconnected the hoses and pitman arm from the power steering valve and screwed it onto the center link one or two more turns. I did that years ago; don't remember how many at this point.

 

from reading on this forum, one coil cut off usually equals 1" lower on a stock spring, best to cut 1/2" coil at a time , more pita, but you dont want to go to low

 

Hi Guys ,

Well its all apart once again (damn i am getting good at this now 20 min a side )

well to test the theory of some of the input i have received i put the stub axle between the top and lower arms and tightened the ball joints without any spring or shock fitted . If i raise the lower control arm to a level position , which in turn pushes the top arm upwards the arm and the bump stop locate into place , so there is a definite relationship towards the length of the spring and obviously how tight its tension is , all i have to do now is determine what and how much things change .

I have measured the spring and it is 13 inch long which is already longer than the new shorter spring i saw in the link sent to me , not having the old springs i cannot tell what the thickness of the spring should be but mine are 17mm thick .

The ride hieght of the car is almost 125mm above the top of the tyre to the underside of the fender . The springs have never had any use and could drop after a while , but i do not think by an amount of 125mm .

Will keep looking and keep you guys posted and will send some pictures once i have figured out how to send them from my i pad .



John

 

Ok, I'm metric 'tarded, but our 460lb springs are .667. our 550lb springs are .691 diameter, convert that to metric and compare that to what you have. then if its within what you have, but still a taller spring, start cutting
just did a metric search, unless my puter is lieing, your springs are thicker than both of those, but do your own math to be sure, if thats the case , you have a much stiffer spring than you need.

 

Hi ,
It looks like i am sitting with 550lb's plus units , if your information is correct .
Last night i took out the one spring last night and the height was approximately 13.3 inch !! The coils are as i say approximately 17.5 mm and fill the pockets . While the spring was loose i fitted it into the top pocket and lined it up with the hole , then marked the lower section of the spring so it too lined up with the lower hole . I then took a grinder and removed almost a full coil of the spring and put it all back together.

The result was that the bump stop did go higher and is now locating in the very lower edge of the stop , so if i took off another complete coil i think it may even go up a little higher . The next issue is that the body clearance between the top of the tyre (tire ) still stayed the same , looks like i have an off road 4x4 vette , its got at least 3.5 inches of clearance .

My spring manufacture told me not to cut the spring , just leave it and drive the car , but there is no way that the body will settle 125 mm , well i do not believe it will .

I am going to cut the drivers side spring tonight and see if that bump stop alters like the other one and then decide where to from there . I think the springs are too high and have too much tension . If push comes to shove i will get the guys over there to send me some new springs and start all over again .


Thanks for all your help ,


John