Denholm

Ive just recently started to get two different vibrations.

One- When im driving hard I occasionally get some serious vibration around 6000rpm; my exhaust is on it's way out so im assuming it's cuz my cats are shot, no?

Secondly, my shifter is beginning to vibrate more and more.. starting to even rattle a little bit, when i accelerate.. In need of a tranny rebuild? or is it a quick fix?

Just lookin for any input before i go out spending money..

FirstRotaryExp

iTrader: (3)

It sounds like you need to check your motor mounts, tranny mount, rear diff mount, and replace yoru shifter bushings. The cheapest fix out of all of them, and one that should be done first out of age and necessity is the shifter bushings. $11 from teh mazda dealer and make sure you get the proper bushing kit, two of the same are needed. But do note this fix is for teh rattle only, your mounts may be bad/broke or your engine is no longer fully balanced.

aka_rocket

how can the engine become not fully balanced anymore. i got the vibration starting at 3K+. i just finished checking all my mounts. new motor and tranny mounts.

Aaron Cake

iTrader: (1)

The engine just won't unbalance itself unless there is chunk of something missing. In which case you have bigger problems.

Make sure the fan isn't damaged or missing a blade. That will cause a fairly decent vibration.

As for the other vibrations, check all the mounts and your u-joints.

Terrh

iTrader: (7)

I've lost an entire fanblade before and had NO noticable vibration from it. How? I dunno. But it was vibrationless! The e-shaft bolt someohow BACKED OUT! and took a part of the fanblade with it. Oh, and got 5 liters of oil ******* everwhere in about 10 seconds.

First thing to check is the oil level.

Second thing is to make sure you're not using shitty oil, and oil of the proper grade. GTX 20w50 or Rotella 15W40 are both popular choices.

Make sure all your accessory belts are properly tensioned and that there is no play in the accessory pullies.

Check your engine and transmission mounts.

MAKE SURE YOUR THERMO PELLET IS PROPERLY WORKING OR ELIMINATED this is probalby the most important. Rotors not getting enough oil = vibration!

Have someone else drive the car to make sure you aren't just imagining it.

Replaced the clutch recently? Pull the inspection plate and grab a 12mm wrench, make sure all the bolts are there and tight.

I've had nasty vibration appear in every rx7 i've ever owned at one point or another and it always seemed to be something different.

Denholm

thanks, ill investigate them all today

EDIT**
is there anything in the archive on changing the shifter bushings?

trainwreck517

iTrader: (1)

Is this driving or free reving? Is there any vidbration durring free reving? How about driving? If so what speeds?

Perhaps it you could the u-joint on the drive shaft on there way out... the faster you go the worse the vibration is.

Sideways7

iTrader: (7)

Only vibration I've had is from cheapass tires that were onit when I bought it, but I don't think thats your problem.
Where do you feel the vibration? All over the car, in the steering wheel?

Denholm

It FEELS like the exhaust almost.. like.. directly below me..

And It vibrates around 6000rpm free-revving, and the same driving under hard acceleration..
but again - it's only about 50% of the time -> it will do it once, and then i will slow down and start again and it will be fine, almost as if the cats were just gummed up or something..

But as for my second problem- im going to replace the shifter bushings, thanks for that tip

Denholm

I guess i'll check the U-joint too - if it is shot, is that an expensive fix?

Go48

iTrader: (7)

Mazdatrix.com has a short video on installing their short shifter. That will be helpful, but you should also consult the factory service manual for exploded parts pictures.

aka_rocket

any other things to check for the vibration if its not the mounts or driveshaft. im about to the point of giving up now. the pulley? can they cause rpm based vibrations? i torqued all bolts for pp when i was inspecting clutch/pp.

i swapped in another tranny, rearend, half-shafts, drive-shaft. rebuild motor with approx. 12K+ miles, half city, half highway. i have banzai motor and tranny mounts. it drove VERY smooth right before my tranny crapped out on me (3rd gear).

gotta get this figured out. ive been granny shifting at 3K rpm and under. i havent driven hard for over 2+ months now. its my DD.

FirstRotaryExp

iTrader: (3)

Ive had a bad vibration before, throughout the entire power band from a misaligned and tightened front counterweight. Dont ask how cuz I dont know but its been fixed by my favorite Pro. That vibration was evil...like shook the entire car visibly at idle. Installing shifter bushings is pretty straight forward, just remove the rubber boots, unbolt the top plat(3 10mm bolts), pull the $30 plate off the shifter after removing rubber boots and the shift ****, then remove the old bushings. Install in reverse order while making sure you have plenty of gear oil in the housing.

Fish-N-Kid

You can not replace the u-joints in the rx7. you can get a new drive shaft from mazda for about 400/500 bucks. your best bet would be check the local junk yard.

aka_rocket

i put in an almost new driveshaft so it can't be that. the motor vibrates with the car sitting or moving. i looked under the car while my brother revved the car in neutral. nothing to do with the drive-shaft, not engaged. when i installed the new driveshaft and lsd rear end and half-shaft...with my old tranny, it was really nice and smooth. after my tranny crapped out on me (while testing driving it after putting in the half-shafts), its been like that since i put in the new tranny. the tranny is a gtus tranny that came out of my lil' bro's car.

i did an experiment, took all the belts off except for the alternator one and the vibration kinda went away. it came back with the belts on. changed all the belts cuz one was warped. also had the clutch fan off too. only ran it for a couple seconds (20 or so).

i know something rotating is out of whack.

FirstRotaryExp

iTrader: (3)

Your assumption sounds very good actually. If its vibrating when not in gear then its a part of the rotating assembly. Did you install your transmission properly when you changed it out? get the input shaft in properly without binding? Any change to yoru rotating assembly, as in lightened equipment?

aka_rocket

no, nothing lightened. i did get my rebuild done with s5 rotors but i got the matching weight and flywheel to go with it. it was fine with my old tranny so my engine should be fine.

i did have a bit of a problem getting the tranny in but it went in. did a tranny job before and it wasn't any different this time.