My 88 Se was at a transmission shop for a clutch replacement. Well, after the work was done, there was a lot of vibration at 40+mph under load, 4th and 5th gear. So I took it back and found that they had busted the tranny mount in the crossmember. Got a new one installed but now the vibration starts at 55 mph although it is less than before. Shop said u-joints were bad and they sent it out to a driveshaft place. They managed to press out the old ones and I can see new ones on there. Supposedly, the driveshaft was balanced but I still get a vibration at higher speeds. Any ideas?? There was no vibration before the clutch went out so it can't be the usual tires and shocks.

 

Same problem here, except Im pretty sure the bolts holding my drive shaft are looseing themselves.
My crossmemeber was also needing to be replaced.
And I just put another driveshaft in.

 

So spyder, you still have the problem after a new driveshaft. My bolts are on tight so it's not that.

 

Anyone else have an opinion on this?

 

that sucks, sometimes these problems can be hard to diagnose.

could you describe the vibration a little more? definately not in steering wheel or front of car, right? feels like its coming from back of car or the body? you can never rule out a tire or worn suspension part, I dont care if it just started after getting back from shop.

first thing i would try is jack up rear end and look at the bolts holding driveshaft to diff. grab driveshaft and try to move it, make sure U-joints are tight. see if it looks like the shop put a mark somewhere on the driveshaft to line it up with diff. if not you would remove bolts and turn the driveshaft 1/4 turn and put bolts back in. notice if vibration goes away or gets worse. repeat if necessary. if this does not work you can try using 2 hoseclamps put around driveshaft. a little difficult to explain, its kinda like trying to balance a tire with no balancing machine.

might be wrong u-joints or something weird. could try taking it back to shop until they get it right.

 

Can u feel the vibration when you are just sitting in neutral and revving it?

 

I have yet to switch the crossmemeber, so Im hoping thats it. Im awaiting the parts......

 

Update: In neutral I can rev it to redline and it is smooth as a baby's butt. I have been playing with it somemore. The driveshaft bolts are on tight, no slack in u-joints. The vibration can be best described as follows: When the car reaches 40mph in 3rd, it is not noticeable but I start a hear a rumble from the back. When I drop it in 4th, the rumble is more pronounced (under load) but still driveable. When it crosses 60mph it has both vibration and rumble, vibration is felt thru the seat more than the steering wheel. The one important thing I missed out before was if I am 70mph and I let of the gas and put it in neutral, the rumble/vibration does NOT go away until it drops back below 40mph. This may or may not rule out the driveshaft yet.

 

I have the same problem and I know it is my drive shaft. I checked everything underneath and I replaced my crossmember. My rearend is so far including my axles. I just need to get a drive shaft at the junk yard. I don't want a new because I want to replace my whole drive train for when I get a turbo engine.

 

maybe they installed the clutch wrong?

 

If there was something wrong in the clutch area I wouldn't feel the rumble at the rear. It could be wheel bearings or the driveaxles I suppose but that would be one hell of a coincidence.

 

As far as I know the drive shafts for all 2nd gen rx7's come with nonreplaceable U-Joints....That's why if you call and ask to get some U-joints there is no part number except for a new driveshaft.

What probably happened was that the shop messed up your crossmember....then you drove it with that screwed up cross member and that screwed up your drive shaft's u-joints.

And then the shop went to order U-joints for it thinking that would be cheap only to find that they had to order a whole new 489 dollar drive shaft instead....


SOoooooo then, someone decided that they'd get crafty and try some other U-joints close to rx7 spec. Hmmmm
well now? Ask em what "u-joints" they used.

You can't just "look" at U-joints and make a conclusive inspection. These are components that are bending while turning at thousand of RPM and are under the stress of thousands of pounds of weight. SoUnless they're totally destroyed, "looking at them" is useless.

 

Mobius, it was sent to a driveshaft shop and I am sure that they balanced it. Now what u-joints they pressed in, I don't know. I do know someone on this forum found replacement u-joints for the "non-replaceable" ones sometime back. Yes, the first thing on the agenda is to swap it out with another used driveshaft and see if there is any change. I am just being cautious about spending anymore money.

 

I am just being cautious about spending anymore money.

i hear ya. What did the shop say about the presistent vibration?

 

They are a bunch of incompetent bufoons. They just wanted me to go away after they broke the tranny mount and they sent out the driveshaft to replace the u-joints cause they could not figure it out. Since they seem to do more harm than good, I am staying away from that place.

 

do you know if there were any balance washers on the driveshaft bolts BEFORE the clutch change? maybe these "incompetent buffoons", as you call them, lost/ forgot to reinstall correctly those balance washers.

 

I don't know for sure about the balance washers but I would think those are useless after the driveshaft has been dynamically balanced.

 

They're responsible for this problem. They need to be the ones to fix it.

 

2nd update: I replaced wheels and tires with another set and it's not that. Everything at the rear end looks nice and tight and since it is a load dependent problem, I have to conclude it is the driveshaft thats the problem. Thanks to all of you who tried to help.

 

i also have aproblem with a weird vibration in my R. even wen sitting in neutral n revving it i feel the vibration coming from where the transmission is at. can anyone help me

 

Check you tranny mount if it is hapening even in neutral.