Front end vibration-Need some insight.

[Stephen03]

Hi, I have a 86 944 NA, and I have steering wheel vibrations.

Ive tried a few things and would like some advice from someone with more experience. I am getting a steering wheel vibration (left to right wobbling) when at high way speeds. It kicks in around 100 and over 140 is dies down. The car is rock solid, just the steering wheel vibrates.

Ive tried 2 sets of rims/tires both balanced.-No difference
Replaced ball joints- No difference
Replaced wheel bearings- No difference


I inspected all the bushings I had apart and they looked good.

My struts appear to be leaking but they feel good and I think it could be the ''cooling'' oil overflowing. Could blown strut inserts cause a simular vibration?

After searching and reading countless posts about this issue, I think it could be my steering columb U-joints. My steering is nice and tight but Id like to look into this more.

It feels so much like an unbalanced tire but it cant be. How about tire pressures? I am running the recommended pressures.

Does anyone have a diagnosing procedure for steering columb U-joints?

I wish I could set up a camara to video tape my suspension when this is happening.

Any thoughts are appreciated.

thanks

[looneybin]

I hope you are indicating KPH not MPH.
I don't think the struts have "cooling oil" but if they are leaking, then they are shot & that's probably the problem.
The tires could also have uneven wear that causes the wobble

[944 Ecology]

The early cars are susceptible to that vibration at 60 to 80 mph.

Have your alignment done with maximum (but equal) positive caster (not camber). About 2 degrees positive caster will desensitize the front end to the vibration.

[Stephen03]

Ya I wish it was MPH haha.

As for the cooling oil, Ive always put a couple oz of oil into the strut before installing the insert.

Guess Ill have to swap the inserts, anythoughts on other parts I can throw into my order from pelican? might aswell cut down on the shipping.

Oh ya, and how to loosen the nut off the top of the shock once I have it removed from the car? On my VW it took forever with a pair of pliers and an allen wrench in the middle.

[flash968]

impact gun

if the 86 has them, the vibration can be castor blocks, though it typically manifests itself in braking vibration

forgive me for asking but, are you sure the tires are balanced? how recently? i just went through this on another vehicle and it turned out that they used the wrong wheel diameter when balancing them - also, on one car we have we must re-balance every 3000 miles - i am headed in AGAIN for this on tuesday

[Stephen03]

Well I had my old rims on, which I had balanced and didnt help. Then I put my other set of wheels on and had them balanced, no difference after any of the changes.

Its a pretty bad vibration, I cant figure it out, Seems like it should be something simple.

Should the sway bar bushings fall out of the control arms? or are they supposed to be tight?

-Also I notice when I slow down to a stop I can hear a clunk from the front right, and when I start to move forward again I hear the clunk again. This is why I replaced the balljoints in the first place.
Could bad tie-rod ends cause any of these problems?

Thanks

[Slam]

You could ask the tire shop to do static as well as dynamic balancing, and see if you can find out when their machine was calibrated. My 944 did this until I stopped using Porsche wheels. The aftermarkets were hub-centric and could be balanced much better. Cookie-cutters gave me headaches until I took them to a really good shop and bought good tires. You can try removing the wheel, rotating it by one lug and reinstalling.

As far as the top nut on the strut goes, remove it with the car's weight on the suspension, then jack up the car and everything comes apart easily. I think this way is safer than using spring compressors, but do a search here and have a look at some of the opinions.

[962porsche]

its called head shake . if all pick up points are in good condition then try this .when i worked for porsche this was a big complaint with the 944 body cars . the tech bulletin we put out for this problem was to tow the front wheels IN 1/16 inch to a 1/8 at most . try the 1/16 first ! the cause of this is becouse the suspension is from a front drive MK1 VW golf . the golf was designed for a 13 to 14 inch wheels with a rim size that was only 6 inches wide at most . all the porsche dealers had good luck with this . but it is a problem that was never 100 percent cured .

[Stephen03]

Funny how so much has come from mk1 golfs. I used to have a mk1 GTI and its really helped as an introduction into the 944 world.

my alignment is out of wack a little after I changed my ball joints, doesnt pull but the steering wheel is not centered. I had the vibration before I messed with any of that so Im still lost.
Guess all I can do is replace the shocks and get an alignment.

Then try different (non porsche) rims.

On a side note- Im ordering some things from pelican and I cant find tie-rod ends for a 1986 944 WITH power steering. Only the full tie-rod.
and the shock inserts say ''for F&S strut only'' what does that mean?

God I wish I could had enough money to rebuild the whole car.

[John_AZ]

Struts leaking and "clunk" noise-------Replace the struts before you pay for an alignment.

My second opinion is a warped brake disc.

GL
John_AZ

[flash968]

i agree about balancers - i went to a big-o once for a balance to settle a similar vibration - balanced them 3 times before we figure out the machine was not calibrated correctly - then found out it should be done at least once a month - turns out many shops don't do that

but, because of the now mentioned clunk, i'm still going with castor blocks

[Stephen03]

Am I right to assume that 951/968 castor blocks will fit an 86 NA? The castor block is just the rear bushing on the control arms right?


Thanks.

EDIT: just had another look at my suspension and I noticed some of my wheels have like an 8'' strip of weights on them. The guys said they where having a hard time balancing them but jesus.
Nothing worse then diagnosing something with 2 bad sets of wheels. I need an unmolested set to try.

[toolboy62]

I had (have?) the same issue on my '88, it turned out to be a bad wheel/tire (but you said that you'd swapped them around... but anyway I did have my wheels/tires balanced by many many different shops and nobody mentioned an issue, new set of tires, same deal. I finally went over to a friend's place where he had his own tire machine, found that the wheel had some runout, mounted the tire on the best spare wheel that I had and balanced it. When we spun it up we found that the tire had runout as well, wish the shops had told me this up front so I could have sent the tire back! sheesh.

I haven't mounted that tire back on the car yet because it's been raining cats and dogs every free day I've had ever since then (TWO WEEKS AGO....!)

nate

[HondaDustR]

Check the wheels themselves. Mine had a bad shake around 50 mph that was from both front wheels being bent like someone hit a curb head on really hard. Also check that the strut insert retaining caps have not come loose. That also happened to mine and made a clunking noise when coming to a stop, especially over bumps.

[Stephen03]

Thanks for the replys, Im looking into this Weltmeister Front Control Arm Bushings kit, it says its for 1985.5 - 1991 944's but it only cost $46.95! How can they sell this kit when the OEM rear mount is $80.00 per side!

I must be reading it wrong, heres the p/n: PEL-PP911941

[944 Ecology]

Originally Posted by Stephen03

Thanks for the replys, Im looking into this Weltmeister Front Control Arm Bushings kit, it says its for 1985.5 - 1991 944's but it only cost $46.95! How can they sell this kit when the OEM rear mount is $80.00 per side!

I must be reading it wrong, heres the p/n: PEL-PP911941

Wrong bushings... those are the ones at the front of the control arm, not the ones at the back.

[toolboy62]

F&S I believe is "Fichtel & Sachs"

e.g. not Koni, Bilstein, etc. I believe Sachs and Boge are the same

nate

[Stephen03]

Well I swapped the tires for a 3rd time and cleaned the hub/wheel mating surface and the problem is 99% gone, except when I go over a bump on the high way and the weight comes off the front end.

Thanks anyways,

Stephen