tumbling/viabrating at 3500-4000rpm

Hey ive noticed that when i get up to about 3500-4000 it feels like the driveshaft is about to fall off or something there is this crazy rumble/tumble kind of sound and feeling comming from near the back of the car. It’s especially bad when im on the highway because cruising speed is withing 3300-4000rpm for me on my sr20.

so any ideas? a couple friends said it might be the driveshaft mount or something or even a twisted driveshaft? it runs smooth in all rpm ranges except between around 3500-4000rpm. thanks.

its a 92 hatch. hicas was disconnected and a lock-bar was put on.

i got the same problem too, S14 SR
the rumble is most noticable at 100km/h-120km/h, after that its smooth
yeh its the driveshaft.
i haven’t fixed it yet…i’ll post up what i changed when i fix it…
not anytime soon…lol

turns out it was the downpipe and another part of the exhaust resting against the frame causing this vibrating, nothing like some heater hose and clamps cant fix!

hey, if the driveshaft is causing it, how bad is this problem?

hmm ahh ok, are u-joints something i can buy aftermarket? or at canadian tire? lol candian tire ones trustworthy for the price?

i ask because my car vibrates from 100-120ish only…is it hard to replace the u-joints? my mechanic isnt open till Tuesday so I’d like to know how serious this is as well as whether it is an easy job to do, thanks for theinput

it might be the tires or wheel bearings as well, so dont just assume its the u joint

As far as I can remember, Nissan (and most import car manufacturer) driveshaft u-joints cannot be unbolted if they are from the factory. You must press the u-joint out and the aftermarket unit you purchase usually bolts in.