rotarydrifter

ok to anyone that can help, i sure need it.i have a 87 rx7 se and ive searched in the forums for my vibrating problem, and i cant seem to come up with an answer so im posting for some help. Basicly i have a vibrating coming from somewhere, and its only noticable between 50 and 60 mph. its a very fast and strong vibration that i know is not good. It vibrates in 4th and 5th gear only when i am appling throttle and it also happens in between the shifts and in neutral going those speeds. this has been going on for a week now. and i have asked everyone and looked and searched online and i still dont have a good idea of what it could be. here are things that i know that are wrong, tires unbalanced and i know i need an alignment. suspension is from 1987. wheel bearings. tranny has seen alot of abuse and i have a new one ready for it. and the clutch slips. i searched and came upon the u-joints giving problems of vibrating to alot of people but the fact that it vibrates in neutral confuses me. i also went under my car and inspected the driveshaft and looks just fine and there is no play at all. then some are saying ball joints and some say tie rods and then i hear about the steering assist thingy, i dont know what its called but i know what it looks like. tons of people say it could be all those things. based from what i have described what would be the first guess as to what it is and what i should do first. please someone help me im desperate, this car is my only mode of transportion to and from work, and i need to fix it before i get stranded somewhere or even worse damage more parts. so any help would be great , thanks


marc

stock

i read you inspected the drive shaft. but was it off the car because if the u joint is frozen it will not give any play. take the drive shaft off and check the u joint for free movement. lt should take about 30 mins also have an oil catch pan ready for the forward end of the shaft some transmission oil might leak out.
al

rotarydrifter

thanks, i guess i will have to do that, but is the u-joints the best guess as to what it could be? thats what i want to know. i want to fix the most possible problems first then go down the list.

tweaked

iTrader: (4)

It does sound like a drive shaft.
I can't remember what size to use, but you can slide a socket on the tranny shaft to prevent leakage.

rotarydrifter

well than ill give it a go, since i have nothing to lose i guess.

marlaman

none of you are even close to what it probably is. you're thinking too hard and outside the basics of what it is. quit trying to be so smart and think why things vibrate under what circumstances and go form there.

noobs

crashdummy

turn off your vibrator

Impreza2RX7

So what is it noob? j/k Sounds like an out of balance drive shaft or a wheel weight thrown off to me..

rotarydrifter

its not about being a noob or smart or whatever its confusing, why in the world would there be vibrating in nuetral going about 58mph and no vibrating when i let off the gas but still in 4th at 58mph it doesnt make much sense to anyone one that i have showed. i just dont want to try and fix everything just cuz im not sure what the problem is. first i dont have much time and second i am not rich so. i just need some help to try and figure it out, considering this is an rx7 forum and i am pretty sure there is decent people that like to help on this forum, so for those that would like to help me figure this out please let me know any info that could be of use. thanks.

tweaked

iTrader: (4)

okay, why you ask? when mine went out it acted very similar, it would shake like California when the power was applied. when I let off, the vibration went away. I crawled under there and twisted and shook the hell out of it and didn't get that familiar play. but I went ahead and pulled one from my parts car and put it on. Problem gone.
I think it does this because of the way the u joints are installed. It's not like the old v8 days when you could change them with a pair of needle nose. (and probly install them wrong) these have to be pressed, so when they are in the early stages of failure, you only get the shake when the shaft is powered.
That is my thinking anyway. I don't know if my reasoning is correct, just my way of thinking. If you are unsure, put all four corners on jackstands, put the car in fourth and set the cruise or have someone hold the throttle. see if you can pinpoint the shake. This still may not work because of the lack of load at the wheels. But while it's up there you can pull and yank, thump and kick everything connected to the tranny to see whats loose. (not with the motor runnning!)

rotarydrifter

thanks tweaked im headed to the junk yard today to see if i can find a good driveshaft, ill post later when im done with it to see if it fixes the problem. thanks for your help and input.

rotarydrifter

well i bought a driveshaft today at the junk yard there is no play except the bearings dont seem all that perfect, cuz i can feel bumps when you move the u-joints but its barely noticable, im gonna see if it does anything by switching my driveshaft out with this one. but the weirdest thing is, is that all day today the vibrating has stopped, well not completely there is still vibrating but its really light and barely noticable so i dont know im still going nuts!!!

aka_rocket

did it fix the problem. im getting similar symptons.

boost_its_what_for_dinner

i bet you its the front mount on the diff, my broke the little lip that holds the two hole washer on the bolts of the diff and it the diff hitting the bottom of the car well only if you can feel it under and behind you i had to pull out the diff and change out sub frame crossmembers because i did not have a welder available but you can weld it in solid and be very happy if that is the problem, just giving my thoughts so good luck to you