Gearbox slips over 100 kph - 2000 Honda Prelude

run the fault codes
check for failed cat converter blocking exhaust

Check the engines compression. This has been known to happen on real tierd engines that have poor compression, with it comes lack of power from the combustion cycles. If the rpm is raising quickly, and speed isn't, your clutch could be slipping.

If the model is automatic then there is fault in the gear box as the gear is not shifting to the RPM.
Secondly if this the manual version the clutch can be faulty as it is slipping and not fully engaging to the engine.

think impeller drive is slipping on the drive in the water pump

Whilst not familiar with your vehicle, in mercedes it is called highway hop, and was caused by the universal joint(speed related) that goes to the gearbox,they also added a damper to the diff (weight, frequency related)), , in regards the leaf springs, unless the spring hanger bushes are totally knackered it shouldn't cause problems.
Look at
1)bushes
2)unijoints or excess movement of the gearbox output shafts
3)excess pinion movement of diffs(where the uni joint bolts on)
4)ball joints
5)?bent axle (rare but they do do it)
6)swivel bearings in the front diff
Not sure as to your front end set up, but this may help?

gears do not engage on audi a4

The most like ly reason, which is what happened to mine, there is a small gear in the transmission that causes this problem and usually becomes a problem after any work has been done there. It is a cheap fix and your local police station can let you know of the best place to go.

Get your tracking checked. Also check the road wheel are balanced.

It is possible that one of your new tires has what is called a slipped belt which is basically a faulty tire.

If they were able to successfully perform the front end alignment you can almost be sure that all of your ball joints, tie rod ends etc are ok as these really don't attribute to "shimmying" felt in the steering wheel.

The are several common causes of shaking felt in the steering wheel:
1. Out of balance wheel/tire combo
2. Slipped belt in a tire
3. Bent wheel

Your shop should be able to pinpoint the cause easily.

Take your car back to the shop that replaced your tires and tell them what you are experiencing. They can check your new tires again to make sure the belt on them did not slip.

Oh, i had this problem! you need to replace the clock i don't know the name but you need to replace the thing that shows you in which speed you are and the time and things.