Jahmellowy

Yeah Rod, you are right I actually did not have the handbrake on, it was in neutral with no handbrake on (force of habbit made me say that).

UPDATE:

After driving this car around with a bad temperature sensor (recent issue), the throttle has because twitchy again (the car seems confused on whether it wants to drive sluggish or normal and as a result the car acceleration is not accurate in the low revs). This results in more bucking from the free play. I have replaced the sensor, and I have replaced the engine mount ages ago.

Anyhow, this section here is the only definitive thing I have to tell to date that will help locate this issue: When I am on a hill facing upwards, I roll the car back by letting off the brake just a bit, it does not matter how big the distance is the car just has to roll back. The car now has no free play or delay in the drive train, now noise either, feels like a smooth clutch engagement and drive-train propel. It is like the clutch is DIRECTLY attached to the rear wheels.
However, when the car is facing down a hill and I allow the car to roll forward in gear, clutch depressed I hear a 'clack' underneath the car. Then lets say I allow the clutch to come out I will hear another clack and the car will propel forward. This time it feels that the clutch is delayed in driving the wheels and that delay is fulfilled once the energy from the engine is transferred to the clutch to the res tof the drive train - and the clack happens. Now I depressed the clutch and brake, I let of the brake while depressing clutch, and again clack (sometimes it clacks twice like its bouncing like "CLACK" then "clack" loud clack softer clack.

So with all this, I have come to the conclusion that there is SLACK somewhere and a ton of it. The slack is gone when rolling back on a hill. The slack is there when rolling forward on a hill.

I want to know what it is in the drive train, that would most likely have this slack.
DEFINITELY NOT ENGINE MOUNTS before someone else suggests that lol they are replaced.

s2000Junky

It very well could just be normal accumulative drivetrain backlash. The diff is probably the largest contributor, but you have a long driveshaft from trans to rear end, then you have the rear end play itself and then each side of the rear half shafts. The clacking is likely just backlash being picked up in its entirety as you go from forward to reverse, which is normal up to a point. If your getting a clicking sound from your rear hubs that is different, and this means you need to re torque the axle nuts. Back lash is a normal thing, and with more connections in a drivetrain such as cars with our layout there will be more play, and its heard even more prominently in this car because you have the transmission next to your lap and rear end is under your ass.

C4vettrn

Jack the back wheels off the ground and set your E-brake and put the trans in neutral. Make a mark on the drive shaft and another on the diff housing "inline of each" rotate the drive shaft clockwise/counter clockwise noticing the amount of movement from your mark. This will give you a "rough" idea if the slope is in the diff or someplace else.

Car Analogy

Excellent test. But how much slop is normal? What is the normal cumulative driveline lash?

C4vettrn

Every diff is a little different and I am not familiar with this particular one (first Honda) most my experience is with Dana's. I would ask a member like Puddydad or find a friend with no back lash and compare. This isn't a scientific measurement but will help with the process of elimination. A general rule would be 1/8" is good, 1/4"+ is getting sloppy. The only way to know exactly is to pull the diff or rear cover and use a dial indicator on the ring gear.

redorangefreak

Hey everyone! Sorry to revive such an old thread. I picked up my second s2000 (2007) last year and after driving it a while I noticed a similar sensation described in this thread. My previous s2000 was a 2004 so I chalked it up to the drive by wire vs cable throttle configurations. Any way fast forward to a couple weeks ago and it has gotten worse. Like to the point where I can feel it in 6th gear at 70mph. It is now noticeable in every gear when trying to maintain a constant speed. In lower gears it is violent feeling and in higher gears there is a subtle delay and jerk between acceleration and engine breaking and vice versa. My symptoms are almost exactly as described by the OP. The car has 120k miles with the original clutch and all engine mounts look good. Hoping one of you may have the answer to what this ended up being.

Right now with the car up in the air, in first gear, and parking brake off I can rotate the drive shaft maybe .25 in around between each end of play. When hitting each end of travel I notice a clunk from inside the transmission body. I can also rotate the rear tires .75 in around forward/backwards together at the same time before the drive shaft starts to turn or about 1.5 in if only turning 1 wheel while holding the other still. The front joint of the drive shaft is solid with no noise or feeling of play while the rear joint also feels solid I can hear a click when holding one end still and rotating the driveshaft. I measured the throttle pedal play as well and at the bottom of the pedal there is .25 in of pedal travel before the cable pulls tight enough to move the drive by wire mechanism. I'm not sure what is normal here and would be grateful if someone could compare or let me know the correct specs. Thanks!!!