Picked up an S about 1.5 months ago so fairly new to the scene. All I want to do is return it to its former self.

The S vibrates around 35-50 mph in 4th or 5th to the point where you see the shift knob vibrating violently, how ever when you go past 55 mph it vibrates a lot less. When under deceleration the car vibrates and veers to the right when braking. Also when the car is in neutral now on a slope it does not roll backwards or forwards.

The last owner previously had koni yellows with swift springs and it was way too low where the tire is inside the fender and quarter panel.
Previous owner said the clutch was upgraded. It does feel a lot stiffer than most other cars I've driven. there is also the infamous clutch buzz but i don't think its that making the car vibrate.
It is an 2001 with 150k miles on it
driver side rear brakes also seized about 2 weeks into owning the car and and got new rotors, calipers and pads replaced on both sides.
Regular maintenance done so far:
-trans fluid change
-oil change
-diff fluid change
-clutch fluid
-brake fluid

This all started about 1 week ago.
Things attempted to try to correct the vibrating issue:
- I have since put Ohlins DFV on them and lowered to only recommended spec.
-Added spacers to the cv joint. Still some jerkiness(boggy-ness) when accelerating but don't know if that is normal.
-Inner and out tie rods seized replaced on both sides
-Got an wheel alignment back to stock
-new tires and wheel balance

Mod's added
-Spoon x brace
-Spoon center tunnel brace

From preliminary research on this forum (which is quite extensive thank you ladies and gents for all the knowledge on this platform) that it can possible be prop shaft or diff? Any thing else I can try to hone in on problem at hand so I don't go replacing random things while I'm in there ?
Any help is much appreciated.
while im in here there is a squeaky noise coming more from the drivers side more that sounds like something that is not lubed very well, is this normal?
I have replaced:
-Crank pulley
-Idler pulley
-Tension pulley
-Belt

 

It kinda sounds like one of your calipers is sticking.

Try lifting the car up and spinning all 4 wheels by hand. Does one or more have a lot of resistance?

Obviously, this test has to be done in neutral, with the parking brake off.

 

Are the rear axles OEM? Honda's are hollow but many replacements are solid and many report vibration from that.

 

You still have a sticking caliper. Jack the car up and turn each wheel by hand. Also can buy a cheap laser heat temp gun from amazon and after a drive check temp on each rotor and look for the really hot one to help pinpoint.

 

Same thoughts. Definitely sounds like a caliper issue (in addition to laser thermometer and spin wheels by hand, see if one wheel has way more brake dust than the other wheel on same end).

But could be a second issue with axle half shafts. Either aftermarket, or maybe po swapped axle cups, which puts the worn edgeon opposite side. So now more vibes on acceleration, but you will get some vibes on decel. No where near as bad as the accel vibes, as so much less load, but its there.

Since car was lowered, there is a good chance the axle cups were swapped (lowering soon causes the accep vibe issue, as existing axle cup wear suddenly causes a symptom, since axle sweep over bumps is now in a different range inside cup).

If the wear was severe, the vibes on decel will be more significant. Adding spacers would probably help some, but again, if wear was severe, issue will remain.

You can buy just the cups new from Honda. Way cheaper than buying entire axle. Messy job. Again, don't use aftermarket axles.

Clear up the brake issue first, and if lone symptom of decel vibes still remain, look into axles (if aftermarket) and cups (if excessive wear inside).

 

Thanks you all for the response! I have confirmed that it is indeed my driver side front caliper that is sticky. it is almost 160 degrees more. Also my driver side rear is also 20 degrees more than the passenger rear, is this normal and should I be worried?

 

How can I tell? is there something i should be looking at?

 

Lmk

 

Check the brake lines for kinks.

 

Thanks for everyones reply, finally got working on the car! Indeed it was the breaks that was making me veer right, however there is still a small vibration/ticking sound coming from the back of the car