Loud and Rough Vibrations under decel
 

A little background, 91 N/A, bout 2 months ago transmission broke. Dropped it out got a new one put it in, then it wouldnt start so took it to mazdatrix, John fixed the grounds car started, starter took a dump.

Replaced the starter, car starts fine. Check engine light comes on and car idles funny and makes weird sounds under deceleration. Throttle position sensor craps out and transmission needs a front cover seal.

Take it to mazdatrix new TPS, new front cover seal.

NOW FOR THE PROBLEM................
On my way to school today i got on the freeway, got to over 40 miles an hour in 4th and let off the gas and while i'm decelerating i get a very very loud deep and annoying vibration. It only happens when i'm decelerating from above 40 mph (you know off the throttle, off the clutch in 4th and 5th.) dont know what it is will look tomorrow. Any ideas?

HAHA, listen, I'm gonna take this easy....

WHAT IN GOD'S NAME ARE YOU DOING DRIVING 40MPH IN 4TH GEAR?!?!?!?!

Hot nasty sounds coming from the transmission on decel...
1:) Engine bogged down ??? (2 gears too high maybe?)
2;) Trans fluid non existant or dirty as sin, or not at full lvl..
3;) Pilot bearing issues / Misaligned clutch


Explore these 3 ideas and get back to me, my 325i (m30 series) made the same sounds because of reasons 2 and 3 ...
just my humble opinion and experience.

I dont understand why 40mph in 4th gear is a problem, thats where you're supposed to be when you shift it even says that in the owners manual and yes I did read it cover to cover on top of that, Trans fluid is brand new (Idemitsu) car is not bogging, engine runs perfectly and only has 3600 miles and is nearly brand new. I'm thinking maybe pilot bearing but i hope not and how the hell would i have a misaligned clutch, it was aligned before i took the trans off and it works perfectly under acceleration its just vibrating uncontrollably under decel at over 40 mph.

Possibly a driveshaft issue? I have heard of driveshafts causing vibrations when they are about to fail. Check it just to be on the safe side!

No.

TPS issue, if the new one was put in, was it adjusted??
one nasty symptom of an improperly adjusted TPS is bucking and rough decceleration.


http://howto.globalvicinity.com/gv_w...i=58&co=1&vi=1


Read the first paragraph.

Pull to 40mph in 2nd gear then let off the gas.You will likely not have the problem there. Operating these cars at 1500 rpm is like taking someone outta hawaii in august, dropping them in alaska in january and telling them to run a marathon. It just doesn't work out.

I would agreee that these cars don't like to be driven slow they really like it in the higher RMP range. I would suggest the driveshaft as well specifically towards the rear U-joint. If it shakes during acceleration it is ussualy the front U-joint and if it shakes during decelleration it is the rear U-joint. wvumtnbkr and I both encounter driveshaft issues I made a thread about it a while ago. My front U-joint broke and beat the crap out of the tailshaft on my transmission.
Here is my thread I hope this helps you in your quest to fix the problem

Ok, i'm going to look into the drive shaft, u joints and the tps.

I dont understand why driving at 40 mph in 4th gear is a problem. I have always been doing it since i got my car and it is above 2000 rpms. You get to 38 mph at 3000 rpms in 3rd gear and you shift right, so 40 mph in 4th gear brings you to like 2100 rpms its never caused me a problem before and yes i know how to drive my car :scratch:

There is nothing wrong with going 40 in 4th gear. I do it all the time when I drive I shift at 3000-3500 RMP's cause I have an exhaust leak threw my o2 sensor and it comes into the cabin and at higher RPM's my eyes are on fire. The previous owner of my car cross threaded the o2 sensor in. Forgot my thread in the last post

https://www.rx7club.com/2nd-generation-specific-1986-1992-17/transmission-fiasco-768307/

Fixed?
 

Did you fix the problem or are you sevenless?

well I've kinda fixed the problem. New drive shaft, new tires, wheel alignment and balancing. I also bought the S4 LSD and installed that but now instead of the vibration being at 40 mph now its at 60 and it vibrates when the car is moving. No vibrations under 60. Its so annoying. It starts at 60 and then keeps going, it makes my chair feel like a massage chair and I think its my transmission mounts.

I have a automatic to 5spd swap and the mounts that are on it are just 2 pieces of steel so i'm not sure i'll have to figure it out.

im usually in 5th at 40mph but thats really the lowest you can go in 5th gear or else you have no power whatsoever. im trying to get the best gas mileage i can get here hahah it doesnt matter what gear your in the car should not be vibrating under deceleration the most it would do it bog out if your in too high of a gear at too low of a speed... why would you put so much stress on your engine all the time especially daily driving i just couldnt keep it in 3rd at 40mph.

it most definitely is your tranny mounts i was actually just thinking that before i read that post

ok well i made a (buying) thread in the west section for the at to mt mounting brackets if anyone has any made. I'm going to make one in the 2nd gen parts thread see if i get anything.

AND BEFORE ANYONE SAYS: "You can just make it yourself....." Please know this, i dont have the TIME, EQUIPMENT, MATERIALS or the DRIVE to make one myself so do not post in my threads about making one yourself, unless you're willing to make one for me. Thanks