scorp965

I just picked up an AP1 S2000, and have noticed a vibration while cruising at freeway speed (75-80mph).

The vibration is cyclical; the car will be smooth, then it vibrates for a couple of seconds, then vibrates again - the shifter is the most noticable, but at night you can see the headlights bounce with the vibration, so the entire car is vibrating.

I swapped wheels / tires and the vibration remains, I also removed the center console to check the plastic ring on the top of the transmission tunnel, it's in good shape. I am having the fluids (transmission, differential) changed tomorrow, but the vibration is troubling. The car seems to run & drive fine, and the vibration isn't present at low speed, just 75-80mph.

Here is a cell phone vid of the shift knob while cruising at 75mph with cruise control enabled:
[media]http://www.youtube.com/watch?v=27rip1vEFQM [/media]

zeroptzero

if you can drive in and out of the vibration and it's based on certain speeds it could be a wheel balancing problem.

BuckyN8

Mine vibrates like that as well. Never really thought anything of it. Maybe an engine damper would help IDK for sure?

Robert O

I'd get the tranny and differential lube changed out first and go from there. Do you happen to know how long since either was changed?

scorp965

I just picked the car up 2 weeks ago, but it has a full dealership service history; the diff was changed about a year ago under an extended warrenty by Honda.

I picked up some LE 1605 for the diff, and RP Syncromax for the transmission; I am going to inspect the rear axles while it's on the lift.

Robert O

Not sure what weight that is on the LE 1605 but it needs to be 85/90.Same with the RP Sycromax. If it is a 10W30 range MT oil it should be fine. I used the Honda MTF so I could be sure I was getting the proper viscosity and application lube. I'll wager you'll be surpised how dirty the rear end oil looks when you drain it. Assuming that you are performing the service yourself.

scorp965

Update: vibration is still present, the car's shifting is improved, and the fluids which came out needed replacement.

With the car on the lift I checked out the suspension; everything seems to be in order, with the exception of 1 missing bolt on the front of the drive shaft. I ordered a replacement yesterday from Honda, but it's a special order part, so delivery may take a few days.

The next step is probably an alignment.

Shadow_S2K

Have you checked your motor/transmission mounts?

SOL1D

^ I second the mounts.

sharkbite

You need to check the white plastic piece at the end of the shiter, sometimes that can ware out. The part is cheap from honda. Also grease the shifter.

https://www.s2ki.com/forums/index.php?showtopic=772277

That is the DIY regrease. Good luck!!