Shaking during braking at certain slowing speeds

[Top Banana]

hey guys
Quick question regarding vehicle shaking that is felt in the steering wheel along with the entire front end/car shaking noticeably.

I have a 71 Charger 318 power steering power front disk car and it has a really noticeable shake when braking and going in a straight line from around 45-25 miles per hour. Ironically When braking at those same speeds and I have the wheel slightly in a turn or rounding a corner it doesn’t occur. I assumed rotors/ front end and or wheel balance but the wheels were balanced and twice to be certain and the rotors aren’t shaking or pulsating at low and or high speeds. Also tested the ball joints and tie rods and they are all fine. I know it needs an idler arm for sure and I can feel that in the wheel but never had one effect braking, then again I was a GM guy until recently.
Before I go and start changing rotors and wheel bearing, is there anything else it could be. The shake is really noticeable on the steering wheel and it feels as if the car is shaking hard in a back and forth motion almost like an antilock brake.
Any help is much appreciated.
-Top Banana

 

[BeepBeepRR]

Balance the brakes.. Bleed them starting from right rear,left rear,right front and left front. Sounds to me that you dont have they system balanced. Unbalanced brakes will cause pulling and weird steering.

 

[Pops1967GTX]

Check Rotors are flat ,smooth. they might have a warp. your brake pads can't clamp your rotoras easily. ... You might notice a vibration on the steering wheel as well, especially if it's your front rotors that are warped.

 

[khryslerkid]

Check tie rods, idler arm and center link for play.

 

[Lefty71]

Funny how the replies vary greatly, but they are all good and true!! Even a bad (swell or knot) or out-of-balance tire can do this, especially if the car sits a lot or if you are in a roasting hot climate. I would even try pulling the power steering belt off and retest to see if that has an effect. You definately need to eliminate any known issues, like the idler problem, or you'll find yourself chasing your tail. HTH, Lefty71

 

[Paul_G]

To have the steering wheel shake when brakes are applied is usually a warped rotor. Take them both off and have them checked on a brake lathe. Tire/wheel balance issues will show up at specific speeds regardless of braking.

Looseness in the steering components will compound the problem. Idler arms are pretty cheap, replace that if you know it is worn. Double check tie rods, ball joints, bushings, etc.

 

[Top Banana]

Thanks everyone. I was going to do wheel bearings and idler arm. I think I am going to add rotors and pads for added security. They aren’t that much more and I don’t have a brake lathe anymore.

 

[Top Banana]

Tie rods, ball joints and center-link are tight. The thing I found odd is that it only happens when braking at those speeds and in a straight line. I am going to replace the idler arm and wheel bearing when they come in and I think the rotors for peace of mind. It does feel like brake pulsation, but I have only worked on GM bodies until now.

 

[Johnpat]

Thanks everyone. I was going to do wheel bearings and idler arm. I think I am going to add rotors and pads for added security. They aren’t that much more and I don’t have a brake lathe anymore.

Get a dial indicator to check rotor run-out, there's a spec for being out of round

 

[Frank Mopar]

Get a dial indicator to check rotor run-out, there's a spec for being out of round

Thats correct but before you pull the tire off, stand a straight edge along the tire while you spin it and verify no runout on the tire.

 

[wahya]

Had something similar on my p/u. After driving at speed with no issues, I exited Interstate and had a bad shake in steering wheel. The more that I drove and braked that afternoon, the worse it got. I put my hand on one front wheel and it was warm. When I checked the other wheel it was very hot. The next morning, I went to dealership and they had the truck for over an hour and even took me for a test drive. Could not duplicate the problem. Rotors checked out fine. A couple weeks later, the same thing happened and I went straight to a different shop. The one wheel was hot again and they discovered that the caliper was hanging up getting the rotor hot and warping it.

 

[Cranky]

How old are your flexible brake lines?

 

[Top Banana]

Hey guys. Wanted to pin point it so I replaced one part at a time and it was the wheel bearings. What a difference!
Thanks and being new here I will continue to seek everyone’s advice on B bodies and am enjoying all the threads. Thanks again

 

[Cranky]

Years ago my car had a very faint knocking sound that you could barely hear and could only hear it in certain areas where the sound would echo off of a wall. You could hear it late at night when there wasn't any traffic around. Turns out it was a cracked outer front wheel bearing race and it took me awhile to find it.

 

[Mikeys73]

Just an FYI...
Many years ago I troubleshot similar symptoms, determined the rotor was warped and had them turned, this fixed the problem for a while but when the rotor was warped it overheated in one specific spot, this caused the metal to get harder than the rest of the rotor, so as it continued to wear (after it was turned) the warp and vibration returned. I should have replaced the rotors instead of turning them.

 

[khryslerkid]

Hey guys. Wanted to pin point it so I replaced one part at a time and it was the wheel bearings. What a difference!
Thanks and being new here I will continue to seek everyone’s advice on B bodies and am enjoying all the threads. Thanks again

Thanks for the update. Were the bearings loose, bad, what did they look like if they were bad?

 

[Top Banana]

Thanks for the update. Were the bearings loose, bad, what did they look like if they were bad?

Yea they were loose and marred. The rollers had some pitting and the back of the passenger side outer bearing had galled marks where it rubs against the washer. Bad repair from some previous home mechanic and I’m glad I pulled them. One had a broken cotter pin and the other was so loose I didn’t even use a wrench. Smh.
Repacked all the grease with high temp cleaned the spindles and now good to go.

It’s my first mopar and I’m a GM convert after having restored and collected 442s for 20+ years. My first car I ever saw was a 71 SuperBee at a local show and I always loved the 71-72 extreme coke bottle bodies. I know the 73-74 cars a similar minus all the yearly idiosyncrasies that I am learning while parts searching but I love 68-72 mopars. Still dreaming of a 70 SuperBee and a 68 Charger. But I will say my 71 Charger 500 318 Console auto car has me in love. She’s a double build sheet car (found both this week) and pretty much a survivor minus some shady work here and there.
Numbers matching motor, trans and the radiator support along with cowl, build sheet and trim tag. She’s has everything you would want in an R/T big block but she’s just a 500 and small block. Isn’t it always that way, lol ha.
Godspeed Everyone