Newbie trying to diagnose trans+shaft+LSD status.

[Dr.Ling]

The AE86 is pretty new to me, but I suspect there's something wrong with my transmission and/or driveshaft and/or LSD. I assume everything on my car is OEM and not replaced.

The first thing I noticed when I got the car was all the noise / whine, sounds like it's the transmission. Sounds like I'm driving in reverse in all gears, you all know that sound, and it's only there under acc/dec. I can't believe this sound would be the LSD.

Second thing is the abrupt nature of the clutch, bites suddenly, and in neutral with the clutch engaged / pedal up, there must be contact. Normal for an aftermarket clutch, but not for an OEM I guess. After every shift / releasing the clutch there's a slight "clunk" from the rear of the car, as if there is too much slack in the driveline somewhere.

I changed trans.oil to RedLine MT90 yesterday, but no change in the whine yet, but from experience with RedLine MTL oil in my MR2 Turbo it became better over time.

As I was under the car I tried to feel for slack in the driveshaft. It doesn't move up or down or sideways, but I can rotate it by hand either way about 5 mm / 15 degrees before the wheels turn.
With the rear wheels off the ground it takes about 10 degrees of rotation of one wheel to get the opposite wheel to rotate, which to me seems like too much of slack. Turning one wheel back and forth 45degrees, the other wheel barely follows.

My current plans for the car is a total brake + handbrake overhaul, and then a KAAZ 2-way LSD, then new springs/shocks/camber plates/RCA.
I guess I should replace my ring and pinion when I change to a KAAZ?

Anyways, input needed! Any of the above sound "normal"?
(EDIT: Edited the text after checking the car again... the slack wasn't as much as I thought first... might be normal for the OEM LSD)

[banpei]

First thing is probably your crownwheel. Most hachis suffer from it, especially driven hard. You probably notice it most between 60km/h and 90km/h.

[Dr.Ling]

You mean the crownwheel in the differential (meaning the "ring" in "ring and pinion" / R&P)? Or is there such a wheel in the transmission itself? Cause it sure sounds as if the whine comes from the transmission...

[The Doctor]

whining (when the sound goes up and down with your speed) is deffo the R&P, i had that once and i also thought it came from the box, it's transferred through the driveshaft

[Dr.Ling]

You might be right Doc, but to be clear; the whine doesn't follow the speed of the car, more like the RPM's when acc/dec - no whine if I coast in gear. So if I accelerate thru 1st - 2nd - 3rd - 4th, the same whine will repeat itself in each gear, starting low and getting higher in pitch when I step on the gas.

My LSD and R&P are probably ready to be replaced anyways, so we'll se if the sound disappears after that

As I wrote, I'm thinking of a KAAZ 2-way, easier to get a hold of than a Cusco. And there are 4,778 R&P's for sale thru one of the vendors @ Club4AG.

[The Doctor]

hmm, that's strange, because if the wine is the same in each gear, then it has to be something in the engine or ingoing axle (dunno how it's called in english ) in the box.