Shaking in front end

ThunderDave

Registered User
I just replaced the rack and pinion on my 91 SC, thinking it was or at least part of the problem of shaking in the front end. It did help a lot. The shaking is no where near as bad as it was before. But there is still shaking while braking and mostly on the drivers side.

It did this when I bought the car in July of 2003 and I replaced the rotors and put on new pads and the shaking went away, but has slowly come back over the last 6 months. Could there be a problem with the caliper on that side causing this to happen? I've got 2 more rotors I could put on there, but I'd really like to fix it instead of put a patch on it.

Is it hard to rebuild a caliper? I've got another left side caliper I can rebuild and put on there if that is the problem. Anyone have this before?

Thanks!
 
Is it shaking? or more of a pulsation as the brakes are applied? Pulsation would indicate warped rotors.
 
I would try the new rotors again.....Just my .02 worth.....

When I bought my SC some years ago, the original owner said that he had the same problem......After only 21,000 miles, he put two sets of rotors on it...... :eek:

I have since put an additional 106,000 on her and have had no rotor problems.....

When you said that the problem came back, how long before you noticed it again?

What kind of pads are you running?
 
Check the condition of your strut rod bushings. Replacing them on my car fixed the same problem you are reporting on yours.

Bryan
 
I know the upper and lower ball joints need replacing as well, but I'm having to do a little at the time. I might try one of the rotors I got from "the-big-e" and see if that solves it. If it does, I might get the caliper rebuilt. The outside surface of the rotor is pretty smooth, but the inside surface has some good groves in it. Maybe the caliper hasn't been releasing . Would that cause the rotor to warp from getting too hot?

Thanks for the help.
 
Shaking

I had a problem like that on a 74 dodge truck once and it ended up being a crack in the frame where the stering box was mounted :rolleyes:
 
the-big-e said:
That's possible......But you don't drive like you are in an auto-cross, do you?

No, I haven't ever done any auto-cross driving. Hopefully the weather will cooperate this weekend and give me a chance to check that rotor.

That would suck if the frame was cracked.
 
I'm with SuperChicken on this one these make a huge difference and the factory bushings are just terrible. If you haven't already replaced them I would get a set of the Moog strut rod bushings from Rockauto.com I think they were $20. Mind that there is two sets of strut rod bushings... the ones at the lower control arm tend to go bad well before the ones at the frame. I haven't replaced the ones at the frame and it seems fine at 100,000 miles. I have read of guys who never had to replace the ones at the frame.
If the problem still exists after that and you think it's the brake rotors, changing pad type next time you do the rotors is probably a good idea. Some pads seem to make a significant difference in how long the rotors stay true. There are lots of posts about that if you search.

SuperChicken89 said:
Check the condition of your strut rod bushings. Replacing them on my car fixed the same problem you are reporting on yours.

Bryan
 
Ummm-
MN-12s don't have "frames"-unibody construction. :rolleyes:

Strut rod bushings cause the problem you describe-be warned-they are a PITA to remove.
 
As far as the strut rod bushing, I just got some from Rockauto. I guess I'll document the process and confirm how much of a PITA job it is. As far as brake pads, I've have a set of Performance Friction (Clover, SC) Carbon Metallic pads on the front of my SC. I love the pedal feel, they don't generate much dust to screw up your wheels, they stop well and don't seem to be that aggressive on my rotors.
 
Birdman93 said:
Ummm-
MN-12s don't have "frames"-unibody construction. :rolleyes:
QUOTE]

Why are people such wankers over minor details. Does this make you feel smart? Allow me to :rolleyes: about how anal your comment was.
So I meant "subframe", I don't think anyone except you had a problem interpreting the language I used.
 
I knew what you meant, but to be fair, I was thinking exactly the same thing. I couldn't really ascertain whether you knew or not from the post, but I assumed you just made a mis-statement.
 
NCredSC said:
I know the upper and lower ball joints need replacing as well, but I'm having to do a little at the time. I might try one of the rotors I got from "the-big-e" and see if that solves it. If it does, I might get the caliper rebuilt. The outside surface of the rotor is pretty smooth, but the inside surface has some good groves in it. Maybe the caliper hasn't been releasing . Would that cause the rotor to warp from getting too hot?

Thanks for the help.

Bingo .... you pegged it when you admit to your ball joints needing replacing. My 93 was doing the shimmy as well, even after doing a brake job. Further checking revieled bad lower joints. Replaced them and no more shimmy.
 
Well, I pulled the rotor (see pics) and put on on that I got from Eddie. The rotor has not been turned and I left the pads on there. The vibration is a lot less and from this and looking at the rotor, I would think a bad caliper is causing the problem.

It's hard to tell from looking at the pics, but it has more grooves than a 45. So I think I'll go ahead and start with doing the brakes (calipers, rotors and pads) and see what happens.

Thanks for the help guys.
 

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I have replaced everything except the brake lines, sub frame, and that cross section that the front of the strut rods mount in and I still haven't solved the problem. I think it's in the sub frame or in it's mounts but I haven't gotten around to that yet. Messing with the mounting of the tire will help some but won't solve the problem.
 
NCredSC said:
Well, I pulled the rotor (see pics) and put on on that I got from Eddie. The rotor has not been turned and I left the pads on there. The vibration is a lot less and from this and looking at the rotor, I would think a bad caliper is causing the problem.

It's hard to tell from looking at the pics, but it has more grooves than a 45. So I think I'll go ahead and start with doing the brakes (calipers, rotors and pads) and see what happens.

Thanks for the help guys.
Sooooo.....that's what they're supposed to look like :confused: ........

I thought the grooves just gives the rotor more suface area for the brake pads to grab hold of........ :D
 
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