Front End Quiz, Ok Doc Options

[r_towle]

Here is the situation.

Wobble at highway speed.
Felt in hand, in steering wheel.

New tires, new rims (several times)
Jack car up,
No tie rod wobble at all (hands at 3 and 9 oclock, nothing)
No ball joint wobble (tire in air, long bar underneath..nothing)
New bearings.

We currently have this car off the road for the winter...and we will remove the entire front end assembly this time.

so, there is the question...
Where is it???

Rich

[SirAndy]

Where is it???

i'm no Dr., but ...

have you checked the steering rack itself for play? i had one go bad on me ...

another thing to check is the rubber disk that connects the steering shaft to the rack ...
(IMG:style_emoticons/default/idea.gif) Andy

[r_towle]

ok, the rubber I can figure out how to check...look, see if its broken...replace...
How do I check the rack?

At this point I am hoping its maybe a bushing gone bad...just happens to get nasty on the highway...

I do however feel a slight clunk in the wheel when I wiggle it side to side while standing still....

Its all coming out.
I need to figure this out, its my kids car....
So, up she goes onto her perch...and of course, while we are in there...new everything...


Side note.
Andy, while its winter, and Im re-doing my suspension, on my car...I am going to figure out some sort of bearing support for the anti-sway bar (clunk on gas tank) issue.
I have a good idea, just need to measure up, and I think I can get all the parts from McMaster Carr...should be straight forward, and hopefully a good solution.

Rich

[dr914@autoatlanta.com]

I always say that if one has front end shake, check the wheels and tires first second third and fourth. If you have completely replaced the wheels and tires with a known good set from another car and the front end still shakes the wheel, and the car is not too toed in, and the things you checked are good, move the steering wheel with two fingers to see if there is any play at all, and if so look down the column and then out to the wheels to find the play (may be the u joint at the firewall carpet)
The clunk is probably a loose insert nut holding in the strut insert.


There are some other stupid things that have to do with the calipers and rotors but that is a start.

[r_towle]

I always say that if one has front end shake, check the wheels and tires first second third and fourth. If you have completely replaced the wheels and tires with a known good set from another car and the front end still shakes the wheel, and the car is not too toed in, and the things you checked are good, move the steering wheel with two fingers to see if there is any play at all, and if so look down the column and then out to the wheels to find the play (may be the u joint at the firewall carpet)
The clunk is probably a loose insert nut holding in the strut insert.


There are some other stupid things that have to do with the calipers and rotors but that is a start.

Yup, I took my set off my car, put on his car....still shakes...
So its not wheels or tires...I figured it was...been down that route...he has new tires, diffferent rims etc..

I think it must be between the u-joints , or the rack...
Great

I need to take out the a-arms anyways to weld on the tabs for the sway bar...so I can check everything out during that extraction...

Rich

[Eric_Shea]

I always say that if one has front end shake, check the wheels and tires first second third and fourth.

(IMG:style_emoticons/default/agree.gif)

What year? There was an UpFix'n write up that I ran in our regions newsletter about a 914 that had problems but, it was while coming into a corner and loading up on a turn. It was the old style strut/ball joint.

ANY time I've had that problem it's been a tire balance issue.

[dr914@autoatlanta.com]

I always say that if one has front end shake, check the wheels and tires first second third and fourth. If you have completely replaced the wheels and tires with a known good set from another car and the front end still shakes the wheel, and the car is not too toed in, and the things you checked are good, move the steering wheel with two fingers to see if there is any play at all, and if so look down the column and then out to the wheels to find the play (may be the u joint at the firewall carpet)
The clunk is probably a loose insert nut holding in the strut insert.


There are some other stupid things that have to do with the calipers and rotors but that is a start.

Yup, I took my set off my car, put on his car....still shakes...
So its not wheels or tires...I figured it was...been down that route...he has new tires, diffferent rims etc..

I think it must be between the u-joints , or the rack...
Great

I need to take out the a-arms anyways to weld on the tabs for the sway bar...so I can check everything out during that extraction...

Rich

Please remember the loose shock insert nuts! that is probably from where the clunk is arising

[PinetreePorsche]

Wheels 1-3: 1)-were the bare rims balanced before mounting tires (stem in!)
2) then balanced on a machine w/tire mounted 3)balanced on the car
Then, 4) be sure a warped brake disc doesn't touch the caliper

[r_towle]

I always say that if one has front end shake, check the wheels and tires first second third and fourth.

(IMG:style_emoticons/default/agree.gif)

What year? There was an UpFix'n write up that I ran in our regions newsletter about a 914 that had problems but, it was while coming into a corner and loading up on a turn. It was the old style strut/ball joint.

ANY time I've had that problem it's been a tire balance issue.

I took the fuchs off my car, put them on his car, wobble still happens, yet my tires a perfectly balanced, and create no wobble on my car (I am really picky about tire balancing)

I always say that if one has front end shake, check the wheels and tires first second third and fourth. If you have completely replaced the wheels and tires with a known good set from another car and the front end still shakes the wheel, and the car is not too toed in, and the things you checked are good, move the steering wheel with two fingers to see if there is any play at all, and if so look down the column and then out to the wheels to find the play (may be the u joint at the firewall carpet)
The clunk is probably a loose insert nut holding in the strut insert.


There are some other stupid things that have to do with the calipers and rotors but that is a start.

Yup, I took my set off my car, put on his car....still shakes...
So its not wheels or tires...I figured it was...been down that route...he has new tires, diffferent rims etc..

I think it must be between the u-joints , or the rack...
Great

I need to take out the a-arms anyways to weld on the tabs for the sway bar...so I can check everything out during that extraction...

Rich

Please remember the loose shock insert nuts! that is probably from where the clunk is arising

I have two cars,
His car has the wobble.
His car has been all apart, all nuts bolts have been checked many many times chasing this...
New version of the strut tube (73) so the fastener at the bottom has been checked, its still round, and tight.
I had the issue on my 72, and upgraded to the later stut tube to fix my old problem...
Ball joints are good, tie rod ends check out, I am starting to think it really is farther up towards the steering wheel...the ujoint and rubber joint might be it, but I am starting to think its either the inner tie rod joint, or the rack itself...
I have spares...so I can test...and its winter..he is not driving it roght now...

My 72 has the clunk...its been chased to the aftermarket anti sway bar hitting the gas tank underside in a low speed pothole situation only....high speed under heavy load it does not clunk....I am just designing a good solution, I am getting sick of raising my tank up every month, and the clunk bugs me.
My car has everthing new in the suspension.
This clunk is common I have heard with the hollow aftermarket lager diameter anti sway bars...so it just needs alow profile pillow block and bearing to hold the middle and keep it from flexing so much...
Really its just a fluttering of the hollow tube when you hit a bump.

Wheels 1-3: 1)-were the bare rims balanced before mounting tires (stem in!)
2) then balanced on a machine w/tire mounted 3)balanced on the car
Then, 4) be sure a warped brake disc doesn't touch the caliper

My tires, my car, which we have used to test this..
Mine are balanced on a load balancing machine that applies the load of the road during the balancing process.
Car dealers have them to diagnose wheels.
costs a bit more, but the tires are measured for run out, and roundness using this machine.

So the tires and wheels are fine..
I put my tires on his car....it still wobbles at speed.

Rich

[r_towle]

Ill add to this here, cause the quoting part was hurting my brain...

I have already replaced the following in the pursuit of chasing this...

I replaced the top bearing of the strut.
I replaced the calipers (part of the restoration)
Ball joints, outer tie rod ends
Brake lines
Wheel bearings

Left in
A-arms
rack et all...

So I need to touch all of that I think to track this down all the way...

When the car is fully unloaded, no struts.. the a-arms dont move...
But

It might be an old worn out rubber bushing...gotta dig and see.
Or it might be rack related...
I did get under there and tighten every single bolt myself...
nothing was loose.
So, I will have BOY remove the front end...then we can start from scratch, including the steering rack...and put it all together, measure every clearance as we go...just not a simple hunt on this one...

Rich

[Dr. Roger]

when the wheels are on the car, and it's jacked up, is there any play in the wheels?

(are the wheel bearings snug?)

[ws91420]

Inner tie rod ends? If haven't swicthed to tubro tie rods I would think this to be a likely cause, Had some of this on my 76 b4 I switched.

[r_towle]

when the wheels are on the car, and it's jacked up, is there any play in the wheels?

(are the wheel bearings snug?)

yes as I stated several times above in this thread, they are new and properly adjusted.

Rich

[rick 918-S]

You may have addressed this, I read through this fast, You stated you changed the tires with known good tires and wheels. Did you change all 4? I had a belt separation on a rear tire. This felt just like a front tire with a loose lug nut. I did every thing you stated except look at the rear tires. only changed the front.

Also look at the ride height. Could be an effect of bump steer?

And I think the Dr. started to bring up the brakes. Possibly a sticking caliper.
Ask me how I know.... The front will shake violently. (IMG:style_emoticons/default/blink.gif)

[r_towle]

You may have addressed this, I read through this fast, You stated you changed the tires with known good tires and wheels. Did you change all 4? I had a belt separation on a rear tire. This felt just like a front tire with a loose lug nut. I did every thing you stated except look at the rear tires. only changed the front.

Also look at the ride height. Could be an effect of bump steer?

And I think the Dr. started to bring up the brakes. Possibly a sticking caliper.
Ask me how I know.... The front will shake violently. (IMG:style_emoticons/default/blink.gif)

all four tires where changed
ride height is stock
calipers all rebuilt.

run one year...vibration was the last thing....hunted all year for it...
I will find it now...Ill take all of it out,,,,start from the beginning....
Eventually some POS part will show me its ugly head..

Rich

[ws91420]

Inner tie rod ends? If haven't swicthed to tubro tie rods I would think this to be a likely cause, Had some of this on my 76 b4 I switched.

[John]

Have you put a dal gauge on all four hubs and measured runout?

Also check all four rotors for runout and varying thickness.

I have had out of balance rear wheels cause some slight vibrations that could be felt in the steering. I don't think it has to be in the front end to feel it in the steering.

[Dave_Darling]

That's one of those things that has about six million possible causes... (IMG:style_emoticons/default/sad.gif)

Everything from wheels and tires (yes, suggested ad nauseam already) to any of the bushings in the front suspension, to really blown shocks, to loose shock gland nuts, to bad ball joints, to the tie rods and steering rack and on and on and on.

It sounds like you've gone through most of the stuff, just keep checking. Steering wheel bushing probably wouldn't cause a steering wobble, but ya never really know. Steering column U-joint? Check the rear suspension, particularly the bushings, as sometimes stuff affecting the rear wheels feels like it is affecting the fronts.

Good luck!!!

--DD

[hellsbend]

I'd check that rack VERY closely, wear and damage can be hard to detect sometimes , and they are all getting pretty old. Used ones are fairly cheap, and if the a-arms are coming out anyway it might be worth a shot if in doubt to change it.