Goes into gear but doesn't move
 

Hello Monsieurs, I have a broken Soarer that I'm rebuilding slowly, it's a 1JZ with the R154 tranny.
the car starts up fine and dandy, SOMETIMES when I start it I hear loud *CLUCK*CLUCK*CLUCK* noise where the differential is.. Car goes into gear (Or so I think.. I can clutch and put into first no problem) but does not move, since my dash is Holographic/digital the speed number rises to how much I press on the gas pedal so I have a feeling something is somewhat disconnected...
can somebody give me a peace of my mind? Is it a broken diff? or driveshaft/tailshaft?
if it's any of those.. I'll need help finding the part..

thanks fellas, from Quebec

when you start it you hear a differential noise? Not sure how...your driveshaft or rear end don't move when you start the car, only when you try to move. Now... if you hear clunking when you try to move the car... Then your driveshaft or differential is broken or something... Maybe even a broken rear axle. Your transmission sounds okay but then again just because your speed sensor is working doesn't mean your splined tailshaft didnt snap.

Beyond peace of mind or looking for parts... You need to get under the car and see if you can find any problems with the tailshaft or driveshaft based on inspection. Next would be putting the rear end on jacks and moving the tires to visually hear for problems in the rear end or transmission. If its the rear end you can drain the fluid and pull the rear cover off to see the extent of damage.

Thanks for help! I don't hear diff noise, sometimes there's even no clucking! it's seriously random

bump M2S M2S M2S

I had a problem similar to this before and it turns out the clutch/pilot were completely shot.
it had a clunk noise like you were saying, and there was no friction material left on the clutch so all it would do was slip.

have you checked your clutch yet?

get someone to Look under the car from the side (do not run them over) and see if the driveshaft turns or not in first. If it does not then its in the clutch/trans. IF the shaft is spinning but wheels not moving, it is clearly a differential issue.

shaft is spinning, so it's a diff issue.. but what kind

what kind of diff is it?

soarer diff.. I think open?

sounds like the diff if the driveshaft is spinning and neither of the wheels are spinning.

so, if the Diff is busted I'd be looking for a direct replacement and or upgrade.. what is the best I can get for my soarer? I heard Supra TT auto Diffs are direct bolt-ons, and Aristo's TT auto diffs..
I am not even sure what kind of diff I have in my soarer.. I think 4.08 open
I'm looking for a Auto TT 3.76 Diff which I think is perfect for the R154
since it's a soarer, finding a soarer driveshaft is near impossible.. what alternatives are there? I heard driftmotion 1 piece Aluminium driveshafts can do the trick.. but I need to be 100% sure that it'll mate to the differential..
are there any alternative driveshafts that I can use for my Soarer R154?

bump M2S M2S M2S

bump M2S M2S M2S

trust me you don't want to use a 1 piece drive shaft. lots of noise and is very hard on the diff since it causes extreme shock.

what the sc300 guys here do when they run a r154 with a auto tt pumpkin is use a mk3 front half driveshaft and then use the 2nd part of the sc300 driveshaft to keep the 2 piece driveshaft.

but since your car came stock with the r154, then you wont need to change your driveshaft when you upgrade to the tt pumpkin.
the only thing you will probably have to do is swap the companion flange which is not to terribly difficult to do.

and you are correct you have 4.08 open diff.
when you go to the 3.76 lsd diff, get ready to have a killer 3rd gear!

thanks for the tips and information!
do you have any idea what the problem is though? this loud clucking on start up, the driveshaft spins 1/2 the time but loud cluck noises in the back..