Rear break noise problem (brake)

[luillo]

Damn , just lift up the antenna and slide a new car under it. Glad you have it on the run now.

I hope all my suspicion are right because it really bother me the vibration. I thought it was the DS and I tried to change pinion angle for a long time and did very little difference, I I hope is because it was the wheel vibrating more than anything else.

I post info as soon as I fixe everything on it.

 

[luillo]

Finally got the car back with a new left bearing installed and a whole new right axle and bearing installed. 99% of the vibration is gone 100% noise and brake problem is also gone.

I will be cutting all the rotors and balancing the wheels before I continue looking for any further vibration. I think the light vibration that I feel right now could be the drive shaft because prior all these things I just resolved I did move my pinion angle a lot testing different angles. I will makes sure my brakes and wheels a good then adjust the angle back to about 1- 1.5

My vibration is very very mild only past 90-100 mph which is A huge improvement. Before it was very bad starting at 65 and could not even pass 80 mph.

 

[bullitt boy]

good to hear you've got the problem on the run.

 

[luillo]

good to hear you've got the problem on the run.

Not so fast, damn it.

I think the left side axle is also bent. The left side started to make the Brake noise and is leaking again. I talk to the shop and they will put the shaft in the laid to see if is wobbling like the right one was, if it does it then I will order it.

At these point I will look into a batter axles than the Strange SS, I only got two passes in the track and they got bent.

 

[bullitt boy]

Damn

 

[luillo]

Finally got to put the car in a lift to finish the Russell brake lines in the front and to put more gear oil because of the leak.

I had more time and installed the JPC clutch line and my car is finally very very conftrable to put into gears. The stock line must be a real piece of shit comparing the car before and after is a big difference.

Adjusted pinion angle a little bit because I think when I was chasing these vibration and noises I mess it up putting too much preload poiting the pinion too much down and that was most of the clunking/vibration I was getting from. I did the adjustment not a ride height but I measure it to give exactly 1 degree up and my decel vibration is gone all up to 80 mph but didn't pass that until I get the left axle and adjust pinion at ride height to confirm the fix.

So far pretty happy with the car ride with almost no vibration and the clutch functioning almost perfect.

 

[wbt]

Good to hear.

On the pinion angle, to set it properly the car suspension must be preloaded as you probably know. If you are running poly bushings I would set it at -2*. Solid bushings, rod ends, spherical bushings I would run -1 to 0*.

Stock rubber control arm stuff I would run -3*.

 

[luillo]

Good to hear.

On the pinion angle, to set it properly the car suspension must be preloaded as you probably know. If you are running poly bushings I would set it at -2*. Solid bushings, rod ends, spherical bushings I would run -1 to 0*.

Stock rubber control arm stuff I would run -3*.

I was thinking after the axle is install, rotors cut, and wheels balanced, I will load the car in the flat lift and check how the angle changed and where is at right now because the car seems to be very good with a very light vibration feeling. Is so light that I need to make sure is not the axle.

Then after I verify that I might shoot for -1 or -1.5 due the fact that I have all BMR poly including upper diff bushing.

I am almost sure the car is sitting at -2.3 which is probably too much angle and the reason Im still get the light vibration on decel.

 

[fullthrtle]

glad to see you have it fixed... I see this on stock mustangs coming into shop wouldnt expect the strange axles to bend of just a few hits.

 

[luillo]

glad to see you have it fixed... I see this on stock mustangs coming into shop wouldnt expect the strange axles to bend of just a few hits.

That is the reason it has taken me so long to find the problem. I never could imagine a strange forged axle bent specially in 2-3 runs.

 

[luillo]

Well, got my axle today and I plan to install it over the weekend. I get exited to receive parts even when they are just replacements. Also glad the guy at strange I always buy the parts is very knowledgable about the length on those axles. It took me about a day to confirm what was the shorter axle side on the car. Left short right long.

Seems very easy job the axle swap so I will give it a try.

 

[luillo]

Today I lift the car and check again the lateral and radial runout to compare it to the new axle.

Old axle lateral .10
Old axle radial .09

New axle lateral .02
New axle radial .02

Drove the car around and only noticed the brakes making noise because it probably needs the rotor to be cut which I will tomorrow but no vibration. The bearing is making a whistling noise only when I come to a stop but I can live with that for now.

I still have vibration from 80-100 mph but is driveshaft related, I am almost sure. Tomorrow I will get the car in the lift, read and adjust the pinion angle and check if I can get that vibration corrected.

While testing the car, a C5 corvette pulled up to my side and tried to run away but failed bad. That is when I noticed the vibration at 100. Then I tried 80-100 and is very bad, nothing under 80 mph.

 

[luillo]

I am curious if when I added more angle to the pinion it fixed my vibration under 60 mph but got affected at 80-100. Maybe I need to lower the angle, I will check tomorrow for sure.

 

[luillo]

today i check tires and wheel radial and lateral rounout and think i have one wheel out of specs, the problem is that i can't find details specs on these wheels or tires runout. All the workshop manual says is .45 radial runout for the tires is the max.

here is what i got in my car, wheels and tires mounted and in the car:

Front Wheels:
Left Lateral= .48 which i think is too much and visually wobble.
Right Lateral= .10 not bad, no visual wobble.

Rear Wheels:
Left Lateral= .25 Not bad either, no visual wobble.
Right Lateral= .15 Not bad, no visual wobble.


Front Tires:
Left Lateral= .15 Not bad, no visual wobble.
Left Radial= .10 Not bad, no visual wobble.

Right Lateral= .15 Not bad, no visual wobble.
Right Radial= .30 too much maybe, and has visual wobble up and down.

Rear Tires:
Left Lateral= .17 Not bad, no visual wobble.
Left Radial= .40 too much maybe, no visual wobble.

Right Lateral= .10 Not bad, no visual wobble.
Right Radial= .28 Not too bad, no visual wobble.