66 Riviera SEVERE vibrations during braking

Hi again..

I've had this problem ever since i bought this car ( severe vibrations during braking) The vibrations are felt in the pedal,steering wheel and the "entire front end" The harder I brake, the harder the vibrations get..

What I've done to "eliminate" problem areas:

1. Checked Orginal drums and had them checked for "out of round" they had to be put in a "lathe"

2. Bought new front drums from CARS, and had them checked for "out of Round" they were good..

3. Replaced all 4 wheel cyllinders

4. Replaced "hold down springs" ( not Heavy duty ones) and brake linings and "other brake hardware"..

5. Cleaned brake adjuster..

..

By pulling the emergency brake I noticed that the problem is indeed in the front wheels ( no vibrations while engaging the emergency brake)


Facts: the car has Centerline Billet wheels with no "shim" (or whatever you call it) between the Hub and the rim/wheel.
I don't know the correct "torque" when fitting the lug nuts.. Any Ideas?
The wheels have been balanced PROPERLY, so that is not the issue either..

I've tried cleaning and repacking/ tightening the wheel bearings with no luck ( still the same)

Though I've noticed some "minor pitting" on the right side Steering knuckle/spindle..

Is it possible that the spindle itself is damaged somehow, making the front end vibrating?

Backing plate is secure and ok, on both sides.

I've bled all 4 wheels to the best of my abilities

I'm this close to abanding the entire "drum setup" and ordering a Disk-Brake kit, but It would be a "personal victory" to get the Drum-setup working 100 %..

Later on, I'll try to upload photos of the rims and the Drum-brake Setup on the hub (also the pitting) in order for you guys to check whether or not I've missed something obvious..

I'm getting kinda annoyed at this..

Is there something in the front end that would cause vibrations,when braking BESIDES the Drum-brake?
I had the car through an MOT inspection, and there was a difference at around 20 % braking power between the front wheels and no significant issues or " slack" in the front end suspension ( according to the mechanic)

On a final note.. the car has been lowered 2 " in the front with new springs ( don't know if that could effect braking ,though)

Hope anyone has any clues, that I've missed, causing I'm getting kinda annoyed here..

Sturla

 

Are the shoes on backwards? just asking.....smaller pad towards the front.......Cheap brake shoes do this too. I always buy severe duty stuff. As for the torque on wheels 125lbs in a star pattern is the general number.

 

Hi again..

Brake-shoes are fitted correct (checked)
Any links to heavy duty ones (along with Hardware kits) ?

Sturla

Btw, thanks for taking the time to reply..

 

After checking the above, check the shocks too incase the tire is locking up under braking and bouncing on the pavement (also be dependent on tire hardness).

 

How are the tire rods?... You shouldn't have any play in any knuckle.. I can do it real bad with just one tie rod end loose..

 

This is a long shot but it happened to me when I was younger and had a shop do some work for me. They didn't use wheel bearing grease on the bearings in the front hubs. The regular stuff melted when it got warm and ran into the brake drums, I had the same problems you are describing. Make sure wheel bearing grease is being used. Mike D.

 

Yep. Tie rods are what I was thinking as well.

Put the front of the car up on jackstands. Chock the back wheels.

With the tires on the car, grab one tire and try to rock it up and down. One hand on bottom, one hand on top.

Then go left to right with it. Have someone watch the suspension for any movement at the tie rods.

Up/Down movement is usually ball joint or wheel bearings. Left to right movement is steering related.

 

Try Jason's test first. Steering parts are not rotating and will not cause vibration. They may contribute to it if the wheels don't stay pointed straight during braking. If Jason's check doesn't work, the next thing to check: does the steering wheel shimmy, even a little, when you are driving? You could have tread separation. Since you put new(?) drums on it, if the problem did not immediately reappear, it isn't grease on the drums.

 

Under braking, a really worn set of tie rod ends can cause vibration. Mine shook the steering wheel just as he describes.

 

Non-moving parts do not cause vibration. Loose parts will allow it to increase, possibly, but will not cause the vibration in and of themselves.

 

As has been stated eliminate the wheels and tires as a possibility. Replace the fronts with standard 15 inch wheels and different tires (helps to have a Riviera buddy here) and see what happens. I`ll bet you`ll find your problem :TU: ,
Tom Mooney

 

Hi..

A million thanks for all "input" or suggestions as to the cause of the problem..

Later on today, I'll try to "swap/rotate" the rear tires to front and vice versa, in order to eliminate "tire/wheel" issues.. (BTW the tires are "brand spanking new" mounted on 17 Inch Centerline wheels..)

Having read all suggestions, I feel the need to clarify some things..

First of all..

I'm using "real wheel-bearing" grease ( but thanks anyway)

I feel a "minor/slight" wobble in the steering wheel under normal driving conditions, but nothing serious (like the vibrations upon breaking) BUT.. I guess those to FACTS can be linked..?

After talking to the mechanic which had the MOT-test on my car he did infact mention that there were some wear in what I would describe as the IDLER ARM ( translated from Norwegian), but nothing he would describe as serious or something in need of repair..

Later on today, I will post pictures of the Drum Setup, Steering knuckle/spindle, Wheels and else needed for you guys to "re-check" my "current setup" for faults or anything similar..

As I mentioned earlier the wheels have no "center ring/hub ring" but according to the "tire guys" that would'nt affect the steering in such a way to cause vibrations ( since I'm using lug nuts and not BOLTS)

So far, thanks alot for your input.. I'll be returning, hopefully a bit wiser later on today..

Sturla

 

Why would the steering wheel be wobbling at all with new wheels and tires??? Something sounds wrong with the wheels and tires. New doesn`t always equal perfect...or even acceptable. I would substitute the proper wheels and different tires, maybe the wheels are not properly manufactured? Or, in spite of the fact they are new, a bad tire?
Tom Mooney

 

Guess I have to clarify things somewhat..

I had the SAME problem with OLD tires ( same rims/wheel though)

The NEW front drums ARE NOT balanced ( as there is no brake shop/garage or machine shop) nearby who has the abilty/hardware to actually balance the Drums..

I will however order a complete FRONT END KIT.. just in case.. ( any recommended? ) Moog ?

I have rotated the wheels and tires,but haven't had the chance to test-drive the car, though..

And yes, I did find Slack/play ,specially on the passenger side (front steering/suspension..

Thanks anyway..

Sturla

 

I'm almost willing to bet that the center of the wheels is NOT large enough to fit over the hubs of the drums. When you tighten down the wheels with the lug nuts the drum is getting "Bent" & is now out-of-round. Just for the hey of it try using some flat washers between the wheel & drum & see if that helps. DON'T drive it like this for any period of time. We're just checking to see what happens. If this makes it better, maybe not perfect, then you have a place to start looking. The center of the wheel can be enlarged or the hub of the drums cut down.
Just my opinion.

Tom T.

 

Thanks.. I'll try that tommorow, Tom.. )

Sturla

Rear Hub :


Front Hub/wheel:

Front drum assembly :

 

You need to remove the hubs, knock out the studs & clean off the rust!!! Originally the hub had a paper??? shim between the aluminum drum & steel hub to cut down on galvanic corrosion between dissimilar metals coming in contact with one another. Then prime & paint lightly to help ward off corrosion. The rear wheel hubs look larger than the front??? Could be just the picture, but the front wheel doesn't look to be centered. Is the center of the wheel fitting over the hub in the front??? If not for sure it's the problem. If the center of the rear wheels is in actuality larger than the front then just swap front to rear & vice versa & see what happens.

Tom T.

 

Do not expect a local machine shop to balance your drums. They are already balanced as needed at the factory. Evidence of this balancing is apparent if you look. A drum that required balancing will have circular spots machined in them near the edge on the outside (usually) of the drum. You may only see a portion of the effect of the circular bit that was used to do the deed, like a "half-moon" missing from the drum.

Note that ANY shaking (thus my original question) at speed is going to be greatly magnified on braking. The more brake pedal, the worse it will get. Brakes make a LOT of "negative" horsepower.

 

Going back to the steering parts, on my father in laws truck, when applying brakes, it would just about shake you off the road, scary like, problem was a driver side outer rod end with play in it, if there is significant play in yours it wil happen, especially if your alignment is out a bit..