Front end wobbles under medium braking
 

Hi,

I'm new. I just helped my girlfriend buy a 90 300ZX. She picked the car on her own :) regardless, I've noticed that under medium braking it wobbles noticably from the front end. Has anyone else experienced this, would someone be willing to point me in the right direction.
Great forum,
Ezra

wobble = shudder
:)

Warped rotors.... replace them. oh... and welcome to ZDriver! :D

Thank you! Am I correct in assuming that its just the front rotors since it seems to be coming from the front end only? About how much are the rotors? I can do the work myself. I really appreciate you answering my stupid questions

The fronts are the main cause. Just to make sure it's the rotors tho... IS THE SHAKE IN THE STEERING WHEEL WHEN YOU BRAKE?

Check out Courtesy Parts ( http://www.courtesyparts.com/z32_brakes.html ) for pricing. Also call AutoZone / Checker / Kragen / NAPA to compair prices.

yeah the shake is in the steering wheel, you can feel its coming from the front suspension

girlfriend got good taste... what kinda car do you drive? sounds like rotors... there not cheap... and these z32's have a slightly different caliper setup its kinda a pain but also helpful... hopefully you know how to work on cars. make sure to change to brake pads with the rotors if thats what it comes down to.

She has excellent taste, and shes learning a lot on her own. The best part is shes liking it :)
Haha right now I drive an 88 Subaru Wagon (4WD on demand), before that 2002 Celica GT and soon my own z32 (hopefully). I just started at Western Washington University. I'm in love with that car but it lacks a ton of power (the celica). I've had to do a lot of work on my subi (change two wheel bearings, transaxle, break pads, etc) but it has 260,000 on it and it was pretty abused by the previous owner.

Sorry for the extended post.

would turning the rotors help, or are they just screwed?
I really appreciate everyones' help

Yeah, you can get them machined if they will still be within specs.

Thanks for all your help. I have one last question on this topic, where would I go to find out spec for the rotors. I know I could do a search but so far my searching has been pretty fruitless. Let me know if I'm overstaying my proverbial welcome. Thanks again
Ezra

You can machine the stock rotors as long as they don't get machined under the minimum thickness that is usually cast into the rotor itself. If you need new rotors, don't go with oem nissan rotors, they are way expensive. You can buy any el-cheapo aftermarket from your local autoparts store. I generally stay away from the elc-cheapos because many of them will quickly warp after a few heat cycles. I went with "Brembo" brand rotors mainly for the quality of materials which means they're less likely to warp. You can buy blanks, or drilled, or slotted, or drilled and slotted.

On the 1990 model 300zx, they came with 26mm wide rotors. Unless they were swapped out for the newer 30mm rotors and matching calipers, you have to be aware of what size is on your specific car.

Besides the possibility of warped rotors, it is common for the tension rod bushings to wear out on our cars and cause similar vibrations. A telltale sign is an oily wetness at the front tension rod mounting points under the radiator. It might be something to check out also.

Welcome to the world of Z. Did you get t-tops or no?

yeah it has t-tops. It seems to be a really solid car. Has a little clicking noise in the engine. Maybe a lifter. Guy said it only happened after he put new (synthetic low viscosity) oil. Chances are hes full of shit and its a lifter, but it runs very strong and we knew going into it that it wouldn't be maintenance free. Thanks for your help! Everyone here has been really friendly

head work on that car is redic.... check the oil level first might just be a little low.... i know my car had some loud freakin lifters... ugh... and when i went fully synthetic it started actin wierd till i discovered the compression was low in a cylinder.... not good.....

NAPA has OEM style rotors for $60, they are great as long as you dont drive the car to hard..

Acting weird how?
Low compression means what in terms of work and cost to fix, (dumb question I know)

to me it means sell car and buy a new one which i did.... but thats just me prolly was already screwed and with synthetic oil whyle more lubby i probably used a less viscous oil than prior so it could have wore a little more and also allowed more compression to leak by the rings... this was what happened to me... i doubt its your problem dont get worried haha... however the 90 style Z32 did have soft valves more prone to bending which would make the head noisy and loose compression and performance and while its probably not your pproblem as long as the car is running good, it would cost over 1k to fix im sure... low compression is... hmm... how to explain. each cylinder on the compression stroke creates a certain amount of psi in each cylinder and if there are any leaks that let the psi numbers drop the performance will suffer engine wil l run crappier.

Man you guys are really great. Thank you all!

in no way shape or form do i want you or any one on here to think im leading you to think this is going to happen cuase its not, its just what happened to me once i switched to synthetic... but it wasnt the oils fault the oil is probly the reason i noticed there was a problem...... however now the more you know :D

just curious.... how much did she pay for the car and do you have any pictures you can post up? we love pictures

hey, another washington z32!!! you two are up at western huh??? should try and make it up the next time we do a canada meet. you should be really close if you are going to western.

Don't worry. I wasn't super-worried about it. I more appreciate all the info. I'm the kind of person that likes to get all the information, even if its not 100% pertinent.

I will post some pics, is this an appropriate place to do it?
If its not I will either add them to my profile, or (since she wants her own zdriver.com account) let her do it later. She paid just over 4,000 for it and it only has 113,000 miles on it.

We would love to attend a meet, shes actually in Port Townsend, we're both young. Shes a highschool student. We know that we're young, but we're out to learn and not step on anyones toes. Its hard not to appreciate a Z32 at any age.

no its not... but its hard to realize but quickly learn the $$$$ a Z32 can rape from a highschooler... please tell me you not like 24 or something if she is in high school cuase i noticed you didnt say you were to....
this would be an appropriate thread to post pics. and damn.... i miss highschool now that im in college....

Welcome to the wonderful world of Z's
 

New front rotors 80.00$
New Tension Rods 120.00$

Girlfriend that likes the z32.....priceless.

Well I'm definitely not 24. :) I'm 18. If there is anyone her age that can invest the time into making the money and owning the car its her, shes very commited (otherwise I'd probably be history).