steering wheel shake....help diagnose problem

[memphiss13]

ok here's what's going on. my s13 is shaking pretty bad. driving anything above 25mph the steering wheel shakes hard. it just started doing this a week ago. also when i hit the brakes it pushes the pedal back out at me. i just can't figure out what is going on.

things that have already been checked and done:
new tires (balanced rechecked)
new rotors and pads
new tie rod ends
and i got an alignment today

the car is a 91 HICAS model.

also this didn't start until after the brake install. but i just don't understand why b/c i have checked and reinstalled the brakes twice since then to make sure that there was nothing installed incorrectly.

[DuffMan]

Maybe your rotors are not balanced enough. Usually I thought rotors came pre-balanced, but maybe something got screwed up.

I think there is a procedure where they can balance the wheel on the car. That way they could compensate for it. If not that maybe they could balance the wheel with the hub and rotor attached.

Or maybe a machine shop could just ballance the rotor by removing material.

[mbmbmb23]

Are the tie rod ends adjusted properly?? Did the guy doing the alignment adjust them during the alignment? You could have installed the new brake pads incorrectly initially and somehow warped your rotors. Now that the rotors are warped they pulsate your brake pedal when you push on them. Take the new rotors to a shop and have them checked out.

thats my best guess.



-m

[mbmbmb23]

If you goto a Nissan shop they can turn the rotors on the car. The 300zx requires this, so they should be able to do it for your car also.



-m

[the head]

check steering rack mounts, also have you checked for play in the wheel bearings??

[Flybert]

I'm thinking that it's your struts. My car with 165,000 miles had a hardcore steering wheel shake until I replaced the stock suspension with a shock and srping combo.

[chineseb0i]

Possibilities?

1.) Strut mounts..mine were messed up and i didn't really notice it untill i looked closesly at how torn they were. When you turn your steering wheel, your struts turn too (ask someone to turn your steering wheel and watch the top part turn)

2.) T/C rod bushing. go to www.pdm-racing.com they offer whiteline bushings which improve handling performance. These are the first bushings to go on 240sx. I suggest replacing them, they'll really improve your handling even if the problem is not due to the bushings.

3.) Besides those two, it probably would be something with the balance/alignment of your tires or rotors.

[memphiss13]

ok i got the rotors turned. they were warped, not really sure how since they were brand new. manufacturer error i guess. i drove it after i put it back together and its still the same problem. to the guy who said i put the pads on wrong, how exactly could they be on wrong. they really only go on one way. but anyway. anybody have any other suggestions. i don't think it could be the TC rods b/c that wouldn't have any effect on braking would it?

[rps13sh]

cheap aftermarket wheels?

[mbmbmb23]

Well....I'm no brake expert but....rotors warp due to getting too hot...like if they overheat then you hit a puddle or something. Possibly a caliper is slightly seizing up and over heating the rotor. Are you re-using the brake pads after you replace/turn the rotors?? I wouldn't if I were you.


-m

[memphiss13]

i drove it down the street and back yesterday with the old pads then thought about the fact that i forgot to buy new pads. i'm doing that today. we'll see if that does it.

James:i was kind of thinking exactly what you are saying something is up with the brakes themselves. b/c it didn't start until i changed them out. i don't agree with what you say about me not knowing what i am doing though. i have enough mechanical ability to handle a brake job myself. but i won't take too much offense to your comment since you don't know me or anything.

[memphiss13]

yeah i asked the alignment guy to help me out but he didn't see anything. i'm pretty sure its just something in the brakes. the calipers could possibly be sticking considering its a car with 165,000 miles on it. this is what happens when you buy a car that sat for a whole year not running. things just start to break. its possible that when i pushed the piston back in that it messed up the seals. since the pads were really low it was pretty far out and wasn't very easy pushing back in. the seals were probably so dry rotted that that caused it. maybe a caliper rebuild is in order.

thanks for the little thinking method tip, it actually works to think simpler sometimes.

[mrmephistopheles]

Take it to your local Nissan dealer and ask them about the TSB (technical service bulletin) relating to a steering wheel shimmy in S13s.

Also, it's possible that your ABS sensors are picking up some sort of metal (they ARE magnetic). I recommend removing your rotors and cleaning your sensors to be 100% sure. I'm kinda leaning towards this, as ABS only kicks in above 25mph.

[memphiss13]

you know what i did notice some metal sticking to those sensors, i'll check that tomorrow. my abs light has been on every since the car has been running but the shaking only started once i put new brakes on. again, i can't thank you enough guys.

[memphiss13]

don't know if anyone cares but the problem is solved. i put my stock rotors back on and the shaking went away. it turns out that the NAPA rotors were not made right at all. i bought two sets and neither would work right. i found that what was happening is that it wasn't gettin flush with the hub at all. so i'm going to napa tomorrow to hopefully get my money back and inform them of this problem in their product.

[Bill Roberts]

Damn aftermarket rotors are POS.

I have been through so many..I cant count anymore..first time out at the track ofter 500 mile break in...they are toast. Warped and cannot be turned to speck. It is where the bolt pattern is that gets warped. JUst totally out of calibration.

Next time..I will get factory Q45 rotors and Q45 calipers and pads and be done with it. For good.

Those are the brakes to have at a decent price.

Install is a cakewalk. I still wanna make damn sure the factory alloys 6.5/15 rims WILL Clear. Hate to have to go through that..general consensus is , no problem.

Glad all is better. I hate that warp..and getting it again as well... No bad but at 65...a little shimmer in the steering wheel.

Whew..I bet you were getting p i s s e d . At least, you now are a front brake expert after all of that crap.

[memphiss13]

believe me i was past insane. felt so good to drive my car again last night though. now i just have to figure out my little boost problem.

[old_s13]

I was just gonna say, ROTORS. That upgraded spring for the steering rack only applies for the 55-60mph shimmy, nothing else.

I've come across SO many poorly made rotors, no sense in wasting time.. its OEM brembos for me.

ps: Resurfacing a rotor does not SOLVE the problem, it only covers it up. If a rotor is warped, it is garbage and CANNOT be used for performance driving. Resurfaced rotors are ONLY for normal folks who use their brakes 3 times a day.

- Mike

[240Driver39]

sorry to bring this thread back up, but i have a question about that tsb involving the spring in the steering rack. I have read that it only applies to earlier s13's, i have the 55-60 shimmy and have taken care of the many of the possible solutions (wheel balance, alignment, etc.) Could this tsb also apply to my 91 240, cause that was what i was unsure of after reading posts relating to this.

thanks in advance

Adam

[rps13sh]

i got brembo crossdrilled slotted rotors $100 per set. they're awesome.

[old_s13]

48237-10V02, costs 2 bucks

[240Driver39]

much appreciated, thanks