djcheezay117

iTrader: (2)

So i've got an 87 N/A and i'm having this problem: Whenever i start driving my car, it pulls smooth, gets up to speed, then when i hit 55 or 60+ MPH It will start vibrating. Like teh whole thing. Steering wheel vibrates too, but if i drive with no hands, it doesnt affect its alignment or nething, cuz it stil drives perfectly straight. When i slow down (40- MPH) The vibrations get worse until it downshifts then it gets smooth but then there are these popping sounds when i finally come to a full stop (stop light, stop signs etc..). What could this be? I use my 7 as a daily driver, and it only recently started doing this. It actually started out when i hit a speed that i didnt know was there, then its gotten progressively worse. Any ideas?????????? Thanks
~Dave

DavidHolmesIII

Trans or motor mount maybe, have you looked under the car yet? I wouldnt drive it around like that, you might break more .

rookie117

iTrader: (1)

could also be the driveshaft

w0ppe

Could be your suspension died at one point, bushings are going dead as well. There are a few things that affect vibration. By "Speed" you didn't know existed, are your tyres of a grade to handle high speeds?

VortecBowtie

U-joint or drive shaft itself is bent is my bet.

incubuseva

iTrader: (13)

If its a very fine vibration then it's your U joint. Don't drive it that much if that's the case. They can break while you're driving then it will really **** something up. Could be you.

r x 7 f c s 4

The tires could be off balance. I sometimes start to vibrate around 60ish but my tires are old *** hell and I can't afford new ones yet.

djcheezay117

iTrader: (2)

Well it varies between a fine vibration and a harsh one. I have tires rated to go up to 140 MPH comfortably. My front suspension was shot about 4 months ago, but i got new struts for it, so they should be ok. Bushings i suppose are possible.
How would i bend a driveshaft in an automatic??? I havent gotten to look under my car thoroughly yet. And like i said, its my Daily Driver, so if its gonna **** up soon i'm wondering where i can get new U-Joints, bushings, (driveshaft if its bent), transmission/motor mounts, and the like.

Thanks guys.

VortecBowtie

if it's a bent driveshaft you can usually find a drivetrain place locally to straighten it and re balance. However, if it is a U-joint, most likely you will have to buy a whole new one from mazda (350$ i think) beacause the u-joints are 'steaked' in. When I picked up my car from my uncle in Colorado we thought it was a bent driveshaft but turned out to be a U-joint. Found a guy outside of of Denver in Englewood that knew how to replace the u-joints with out replacing the whole thing. Chances are if that's the case, you should be able to find some one also...

that nissan guy

iTrader: (2)

sounds like something broke loose.... how hard did you hit that speed bump??

ive seen a loose lower control arm shake the DOGSHIT out of a nissan sentra before... like get on the freeway up to 70 and it feels like its about to come off the road it shook so bad

what you really need to do is get the car up in the air and check visually for damage and physically check for play in the wheels and just start grabbing stuff and trying to shake it... if the vibration is as bad as you say it is it should be pretty obvious... if you still cant find it take it to a good reputable shop

kuromi7

U joints on stock driveshafts aren't replaceable, unless you have a shop do it. Mazdatrix has aftermarket driveshafts for auto that come with replaceable u-joints in case this ever happens again.

http://mazdatrix.com/getprice.asp?partnum=2691-703

I had the same problem. The car only vibrated at high speeds, and I could feel it through the steering wheel. I didn't get to it in time and it DESTROYED part of my transmission and made the problem 10x worse.

phoenix7

as far as the popping, make sure your front diff mount is intact.

What have you checked so far?

misterstyx69

iTrader: (142)

Speed bumps have a tendency to Break U joints.Usually the Rear U-Joint at the Differential..If you check there,you may find what you are after.Also check the Front Differential Mount.That would explain the Clunking..The vibration is because the driveshaft is probably out of whack because of the Speed bump..(and That is Why they call them Speed Bumps!)

djcheezay117

iTrader: (2)

Ok. Thanks guys. I'll check it out and let you know what I find!

djcheezay117

iTrader: (2)

Ok it took me a while, but i got lift time and took a close look at my car.
Here's what i found:
1. U-Joints were fine
2. Very little play in the driveshaft
3. Transmission/motor/differential mounts all fine
4. Oil Pan gasket Leaking slightly-Fixed
5. Transmission Rear Seal leaking-fixed
6. Front Struts fine
7. Bearings fine
8. Wheels Balanced/Rotated
9. Front Brake rotors- passenger side badly warped-replaced with aftermarket ones
10- Front brake pads- replaced
11- Front calipers- lubed and operating fine
12. Rear brake pads- replaced
13. Rear Brake Calipers- passenger side sticking-both rebuilt and lubed up
14. Rear brake rotors- resurfaced and work fine
15. Mufflers had small hole- replaced both
16. Fuel Pump- Not Working Well- Replaced
17. Fuel Filter Clogged- Replaced
18. Rear Struts- passenger side blown- replaced both


That sucked. And there's only more work to do im sure haha.
Thanks again for all your advice!
~Dave

phoenix7

good job. WHat's next?

djcheezay117

iTrader: (2)

I just bought an 87 Turbo shell ... no windshield...crappy interior...i think i'll start on that.
How would you go about getting rid of a rust spot that is right above the windshield on the horizontal support beam?