Vribration in 5th gear, please HELP!

[peaksja]

I have a 90 base S13 FB. Basically during driving in 5th gear the car often shakes [mainly felt in the steering wheel]. The issue also started bleeding into 4th and 3rd. I currently have balanced 18'' tires and rims. I was told that it may be the u-joints so I bought an intirely new[used] drivesahft and installed it last night. After driving the car for a few hours it slowly came back. Is the problem in the shaft itself or could it be the suspension? Is it possible for a brake pad to be appliying costant pressure noticable at higher RPM?
--------------------------------------------------------------------------------

The wheels were balanced less than 3 months ago. I do see that one does not hold more than 20lbs. I am going to buy new one. The tire is a 35 series Kohmo. I wonder since 20lbs is less than half the max 44lbs; considered a flat?

I also had this problem with the original factory rims and hubs.
Any help would be greatly appreciated.

[shayrgob240]

from your title you make it sound like the problem is tranny related whereas it sounds like it's speed related. Since you said that when replaced the DS, the prob went away, then I am thinking that it might be the DS. GO ahead and raise the car, inspect the DS thoroughly, then inspect the suspension/steering for the hell of it to make sure there's nothing wrong w/ it. good luck

[vspec15]

Got your car lowered? One word- alignment

[shayrgob240]

Got your car lowered? One word- alignment

A car that is in misalignment usually causes abnormal tire wear, a pull, or a wander. But worn parts willl probably cause what he is talking about. So like I said, just inspect everything while under the car; bushings, tie rods, etc.

[Jadeskyline]

I work at meinike and had the same problem usually around 55-60 mph. Wnet on the computer at work (all data) and that is a known issue with 240's and it's a tsb more than likely it is alignment. You can go to the nhtsa and look into it further. But to be safe check everything anyways

[peaksja]

At this point I am not going to weed any suggestions out. Based on your input, 1. The DS will be rebalanced with new u joints and 2. I will thoroughly inspect the suspension tomorrow. As for the alignment I'm going to save it for last due to the tires great condition and the car does not pull.

[peaksja]

Looking closer at the issue... it begain exactly at 55 mph and is becoming consistant. At this speed if I lightly press the brakes my steering wheel does vibrate in the same manor but at a smaller scale. (warpped rotor?) I also noticed that once I hit a bump in the road the issue stopped, then hit another and it slowly increased. It has to suspenion related. I am going under.....