So today, it seems like my car has started vibrating.. at first it would do it only when coasting in nuetral. But the it started through all the gears. it isn't too bad but definitely different from the other recent problems I've been having

It kinda feels like the car is running rough, but it hasa good idle and zips up to redline fast.

I thouht I should add, earlier today I did some donuts.. and a little while before the vibrating thing I raced a mustang.. I have an NA s5.

 

My vote goes for rear U-Joint.

 

My first thought.. buuut upon searching I foun that it usually happened when they were at a certain speed..

I JUST REMEMBERED! I recently thought my diff mount was broken(but found that it wasn't) because when engaging reverse or going slow in 1st the car would jolt and shake back and fourth quite violently. Maybe this caused the u-joint to go bad? Or maybe its the same thing?

 

Jack the car up and start checking. Vibrations could be a number of things from tires, brakes, steering to drivetrain.

 

It feels like its from the tranny or the wheels.. I noticed that it vibrates a lot around 25-30mph and when in nuetral and doesn't vibrate when at a stop. Which rules out the driveshaft.. maybe somethings messed up in the tranny? But why would it only vibrate when moving? That means it has to be the alignment right? But why would it start vibrating out of nowhere?

I'm not sure but I really need some help.

 

JEEZUS. Take the 30 minutes and go check the driveshaft/u-joint.

Your post was actually 100% wrong! If it doesnt vibrate at a stop (driveshaft NOT moving)... it would be the driveshaft - or at least something that moves when the car moves.

GO CHECK THE DRIVESHAFT.

 

JEEZUS. I did. And didn't find anything suspect. The driveshaft wouldn't have any stress on it if I was in nuetral which is when it vibrates most. My post is not 100% wrong.

I'm sure you aware what nuetral is. The driveshaft would hardly be moving at all

 

Last I checked, when you're in neutral, driveshaft speed is a function of rear wheel speed... not transmission speed.

So yes, it is.

 

And I personally have never had a vibration out of misaligned wheels - but I'm not saying that it isn't possible. As long as they're balanced, shouldn't be an issue. Maybe you threw a weight off of your wheels when you were tearing up your car doing donuts. I doubt that too... but who knows how long they've been on there (I obviously dont).

 

That is exactly what I mean.. at 20mph the driveshaft wouldn't really be moving much.. and the speed definitely wouldn't match with the speed and intensity at which it was vibrating

 

At 20 mph, the driveshaft would definitely be spinning fast enough to make a fucked up u-joint vibrate.

It doesn't sound like you've pulled the u-joint off of the diff flange yet... have you?

 

No but it still wouldn't explain why the tranny and steering wheel would shake...

 

just spend the 30 minutes and eliminate it. Then move to the other stuff.

 

I will.. But after I do that, i'll be back at square one. And I dont know what else it could be

 

I gave you a list of things to check. Does it vibrate at all while in neutral and at a stop (0 mph)?

 

I checked most of what it would usually be, like driveshaft, tranny mounts, motor mounts etc.. and it doesn't vibrate when at a stop

 

I had u joint trouble, but I had to take it off to see what the trouble was, no good just looking at it, or even just twisting the staff. The mechanic said not the driveshaft, but vibration continued, so I took the driveshaft off at home and both end u joints were shot.
New bearings are really hard to find, a wierd size, I wound up getting a used vert driveshaft with good bearings, if and when that goes I will have to take my old driveshaft and have the yokes bored out to fit a regular size bearing cup at a local shop.
Donuts and racing Mustangs? You remind me of a young guy who bought a Porsche 944 and blew the diff completely doing donuts. And whined all over the Rennist board You have a 23 year old car
treat it nicely, go get a Civic if you want to drive like an idiot!

 

If it only vibrates when moving, regardless of speed, it's somewhere AFTER the transmission....the driveshaft, rear end, brakes, wheels, tires, etc.

Go replace your u-joint(s), then come back.

 

hahaha okay.. i have a kaaz 1.5 way and a rebuilt streetported motor with ~30k on it, and i'm pretty sure it can handle some abuse.

i'm aware that the car is 20+ years old. but the motor and diff are not. and from what i remember the rx7 was a sports car? am i wrong? oh and i know i'm not mistaken about the 13b being able to handle quite a bit of abuse as well. i didn't know i was supposed to baby my Rx ******* 7, if i wanted a bitch car i wouldv'e bought a geo metro.. thanks

and ps. i personally hate civics. and donuts are quite fulfilling

 

I give up. I suppose really you need an adult with electical and mechanical skills to drive over and fix your car and you are unwilling to take advice from knowledgeable posters here on tho board?

 

not unwilling to take advice.. just needed some ideas for what else it could be, incase i was missing or forgetting something.. i guess i pretty much had the right ideas

i can fix what ever the problem is on my own as far as mechanical **** goes. as for electrical, i am ****** clueless

 

Dude, four people say your u-joints.

Check/replace your ******* u-joints then come back if it persists!

 

No no no... because if he actually did that, then someone couldn't magically **** out the solution, bring the FSM, and actually turn the wrench for him.

This is going in circles.

Dude, we've tried to help you - in about 15 replies. You've yet to check the u-joint and report back. I give up.

 

Oh my lord. I have checked the damn u joint. That was one of the first things I checked. I said that earlier.

When I said "driveshaft" I checked the ujoints. I didn't completely disassemble them because **** that. And they seem to be fine.

I asked what ELSE could it be. Since it seems to be none of the regular "ujoint blah blah blah" ****

 

You're not listening, or reading.

How did you check it?

There's not much else it could be, short of out-of-balance wheels, and the car still be driveable.
If it was your transmission, it wouldn't be driveable.
If it was your rear end, it wouldn't be driveable.
If it was your brakes, it wouldn't be stoppable.

Change your u-joints, then come back. It's not a difficult thing to do. The u-joint is a weak link in any RWD vehicle. If there's any sort of vibration, it's always the first thing suspect. It's cheap to replace, and preventative maintenance if nothing else.

Just do it.