Mine itsn't much smoother than yours... It's all psychological....

i have a 12l4 and was able to build the stock diff very smooth. i'll go thru what i do for you.

1-sand the rings with fine grit sand paper in a circular motion counter clock and clockwise. do this on a flat surface of course.

2-place the diff balls (12 of them) in the palm of your hand and place some lub on them (i use ae stealth lube). rub your finger over the diff balls spreading a thin layer over them.

3-insert them into the spur. then place a small dot of lube on the diff balls on both sides of the spur. don't overlube, you don't need much and too much will just attract dirt.

4-assemble the diff with new hub bearings. everytime i rebuild a diff i change the bearings. a bad outer bearing is the cause of a notchy diff 99% of he time. sometimes you can get away with just swapping the inner and outer hub bearings.

5 -slowely tighten the diff an eighth turn at a time. with each turn stop, grab one wheel and the spur and turn the other wheel a few times to break in the diff. then grab the other wheel and spur and spin the other wheel. tighten eighth turn and repeat. the diff should only be tightened untill you can't spin the diff with your thumb while holding both wheels.

the diff may feel a little tight at first but one run and it'll be light silk. unless you slam something with your right rear wheel blowing your outer bearing in which case return to step one and repeat.

also, everytime i rebuild a diff, i use new rings and balls in addition to bearings. i don't use carbide or anything, just standard steel stuff. hope this helps a bit. :)

it's been said before, i'll say it again, look up the slapmaster thread, slapmaster 6000 has a thrust brg setup that will eliminate diff problems forever, just clean and reassemble, silky smooth every time, never buy brg's again, READ his thread you'll see what i mean, spendy but!!!!!!!!! worth every cent!

Numerous people at the track he races at have done the slapmaster for 1/6th the price... We all try and help him... He still comes here to whine....

you mean i wrote that all out for nothing?!?! :rolleyes:

Pretty much......

Notice my sig..... Hahahaha.... It's cracking a joke at him....

Larry... Give me your car this weekend.... We'll get your diff problems sorted out....

I'll go through my box and see if I can find a better TX for you to borrow...

btw, how are you guys doing the thrust bearing setup for a 1/6th the cost? i want to gice it a try.

Hpi 4x9x4 thrust bearing and CRC diff sleve.... Under $5......

nice, thanks

hi im a little new in 1/12th, may i know wat's a diff sleeve? got a part number? thx

3x9 thrust bearings?
 

Will 3x9 thrust bearings fit on the 12l4 diff axles?
3x9 Thrust Bearings

Re: 3x9 thrust bearings?
 

No....

Is this what you're talking about?
4121 - Aerodiff Spacer collar

Yup....

hi

got any pics to show how to install the thrust bearing with the sleeve?