Knocking noise from LSD after FD swap
 

I swapped to Final Drive 4.88 and now the car not passed 100miles ,
diff assembled very good and I hear no noise in straight line but in sharp turning at very very low speed (strating to drive from 0km/h) i hear bad knocking noise , lap lap lap lap lap ...

my car has LSD and need LSD additive in gear oil , i use addinol diff oil that has no LSD additive.

My car idle rpm increased to 1100rpm by my tuner (moto-mike) and the output torque of my car (stage 2 NA) is 15% higher than stock brz .

any idea for removing the noise?


Diff assembly adjustment ranges:
2 N.M torque in pinion preload (toyota service manual recommend 1-2 N.M range)
0.00430 in. Backlash (Toyota service manual recommend 0.00512 in. - 0.00708 in. Range)

The tooth pattern is so good in the range.

LSD makes noise normally

Ok low noise is normal but my noise is over , it is not normal

The noise you hear is the LSD binding and unloading during unequal cornering speeds. That is normal for an LSD running without an additive. Get a tube of LSD additive recommended y the LSD manufacturer, drain all the oil out, insert drain plug then add additive, top off with new synthetic gear oil in the viscosity recommended by the LSD manufacturer. Follow break-in instructions recommended by the LSD manufacturer. Most of the noise should be eliminated, though there will always be a little bit when cornering slowly.

The previous oil before Final drive swap was the same gear oil (addinol without additive) and i had no noise .
The knocking noise is so loud & vibrant and i really can't believe oil additive could silent that vibration.

after break-in additive or no additive LSD makes tons of noise ur clearly not ready to accept this life

i would make a video of how much amazing popping noises mine makes on slow turning but :iono:

stock or aftermarket LSD?
 

Is yours a stock or aftermarket LSD? If it is the stock, Hypoid LSD than there are no clutch packs to make noise and it should be silent. If aftermarket, then follow the manufacturers directions and you should be fine.

change with temp at all? my clutch types LSD is notchy when cold but goes away with some turns

Our ATS and OS Giken LSDs, as well as the OEM Torsen make no noise.

Only our Cusco makes noise.

There is your problem. Get the right fluid in there quickly, or risk needing a new LSD.

I use stock LSD

No change after warmup
I did not changed the stock LSD , i use oem factory LSD (torsen t2)

I will change the oil quickly

Get it back to the shop.
 

A Torsen LSD is hypoid gear controlled, rather than clutch pack controlled. It will not make noise cornering, since it is only gear movement, rather than clutch pack slippage.
It needs to go back to the shop ASAP. Something was put back together wrong. Stop driving it and get it back to the shop immediately. Hopefully it can be fixed without replacing any major assemblies. You might need to buy a replacement/aftermarket LSD if that is broken. As it is, it could lock up at any time with no warning. This is serious. Get it back to the shop.