Dusky

Hi guys!

Passed technical inspection today!

Though, they suspect the car to have a bent lower controlarm.
Is this possible without a collision? Some monkey who replaced the bushings with a big hammer instead of a press?
Is it possible to measure these to check this? (aka, does anyone have these measurements/would be so kind to make these? )
Would go for tubular arms if this one is bent.


Tia!

derekderek

somebody coulda tagged a curb too. you can justify tubulars even if not bent. bad bushing could also make it out of place enough for quickie alignments inspections use to show as possibly bent.

Dusky

Bushings are new
Didn't think they could bend as easy as that. I'll probably go down the impala arm route after I've measured them ( if someone could be so kind to measure theirs, front lower passenger side).
Steering pulls to the right as well ( Im saying caster problem, don't have powersteering).
I'll have to wait for my numberplate to arrive anwyay, so would be cool to solve this ( 2 weeks wait)

DaveL82

What gave them the conclusion it might be bent? with the steering straight measure from the center of the rear hub to the center of front on both sides. On the side they suspect is bent is the wheel measurement closer together (shorter distance)?

Also it is easy for the for the frame mounting ears where the control arm shaft mounts to bend. The typical fix would be to push back in place and weld in gussets.

Dusky

Its indeed closer toghether on that side.
Caster on that side is lower ( if i recall right) made it pull to the right. The wheel is more towards the rear of the arch as well, not really centered in the arch. So the frame ear should have been bent upwards then?
Imma put it on blocks after work and have a better look

gjohnson

What do the shims look like in relation to each other?Drivers side vs pass side.Post pics

Dusky

1 thick shim on the drivers' side, 1 thick and 1 thin on the passenger side originally.
I added some shims on the passenger side to improve things but didn't work ( shims on the radiator side to increase caster). Or maybe it had an adverse effect?

OMF

Just went and measured mine for you.
-Lower A-arm
Widest point 15 1/8" (383mm) pass side, 151/4" (388mm) drivers side.
Inner pivot point outside measurement 14 1/8" (359mm) pass side 14 3/16" (361mm) drivers side

Kacyc3

found this

"Caster is changed by adding or removing different quantities of shims from both studs. Removing a shim from the front stud moves the upper ball joint out and back, creating more positive caster. Adding a shim to the front stud moves the upper ball joint in and forward, creating more negative caster. However, notice the words “in” and “out.” Your camber setting also changes and may need to be reset. If you need a dramatic change you can take a shim off the front stud and add it to the rear stud. This adds more positive caster without changing camber."

but you have to be careful as trying to get the caster where you want it can make your camber way off.

mortgageguy

Couldn't you measure the CA on the other side to compare? Are both sides suspected of been bent?

Truckdriver816

Note: A normal shim pack will leave at least two(2) threads of the bolt exposed beyond the nut. The difference between front and rear shim packs must not exceed 0.40 Inches (10mm) .or check for damaged Control arms and related parts

Dusky

Okay;
Did some measurements. Both frame and arm seem to be out of whack.

Measuring from the big hole in the center of what I think is called to cradle to another component :

BH to drivers side nearest 'small' CA mounting bolt : 205mm
BH to passenger side nearest 'small' CA mounting bolt : 215mm

BH to big mounting bolt of the drivers side CA : 270 mm
BH to the big mounting bolt of the passengers side CA: 275mm

Measurements across the car :

Drivers side CA big mounting bolt to passenger side CA big mounting bolt : 440mm
Drivers side inboard 'small' CA mounting bolt to passenger side inboard 'small' mounting bolt : 400mm
Balljoint to balljoint 1210mm

measurements of the control arm :

Drivers side CA :
Balljoint center to big mounting bolt : 398mm
Balljoint center to inboard small mounting bolt : 449mm

Passenger side CA :

Balljoint center to big mounting bolt : 398mm
Balljoint center to inboard small mounting bolt : 455mm

Kacyc3

inside of your tire in the pic looks wet, you may want to check out your brakes also. I had to have the frame on my car pulled to be withing specs to get the alignment right.

OMF

-The way I measured things is from centre line if the big hole to the closest point where the bolt or nut meets the part. My measurements are bold.
-I can't do some of the measurements because mine's up on the lift.


BH to drivers side nearest 'small' CA mounting bolt : 205mm 195mm
BH to passenger side nearest 'small' CA mounting bolt : 215mm 195mm

BH to big mounting bolt of the drivers side CA : 270 mm 252mm
BH to the big mounting bolt of the passengers side CA: 275mm 255mm

Measurements across the car :

Drivers side CA big mounting bolt to passenger side CA big mounting bolt : 440mm 395mm
Drivers side inboard 'small' CA mounting bolt to passenger side inboard 'small' mounting bolt : 400mm 357mm
Balljoint to balljoint 1210mm 1185mm full suspension droop

measurements of the control arm :

Drivers side CA :
Balljoint center to big mounting bolt : 398mm
Balljoint center to inboard small mounting bolt : 449mm

Passenger side CA :

Balljoint center to big mounting bolt : 398mm
Balljoint center to inboard small mounting bolt : 455mm

That passenger tire is way to close to the edge of the ramp.....please fix it

Dusky

Brakes used to leak on that side, the new calipers sat too long apperantly, doesnt leak anymore now luckily, need to give it a good wash


I wonder, is that on a 2 post lift?
Wonder if the difference would be frame flex from being on a lift vs on 4 wheels.
Ill be measuring my arms again this afternoon. I need a 2nd C3 to measure here, time to break the piggybank :p

DUB

Measuring from the center hole in the front cradle area and outward to the lower ball joints and other areas is not really correct. mainly because you can have sway ion the frame and even IF it is correct....you can still have issues in the frame further back

Here is a schematic of a 1975 frame measurements and where to measure from. This schematic also shows measuring the lower ball joint location also.

RULE OF THUMB: Make sure the measurements of the frame is correct at the 'box'...or the CENTER of the frame where your #2 and #3 body mount locations are at FIRST...then measure out from there.

DUB

DUB

Dusky

Ill measure tonight when im home!

What do you think about the difference in bottom arms?
I've remeasured those this afternoon ( GMT+1 here) and the passenger side one is 7mm longer on the 'small bolt to balljoint' side ( measuring from the bushing to the balljoint to rule out any suspension height differneces.

Many thanks again!

Dusky

If I'm not mistaken the car will always pull to the side with the least caster (most negative) right?

OMF

I think if you take measurement E or F in the chart that DUB posted it will tell you if something is wrong.