Takt

iTrader: (15)

I just started running 1/12 scale on-road. After two weeks of running, the diff is very "grainy", and not smooth at all. I pulled it apart, and cleaned it up, but still have this issue.

Does this mean that either:

1. The diff balls are no longer round or

2. The diff plates are grooved?

Is there a cheaper way (or something I should have done to prevent this) so I'm not replacing diffs every three weeks?

Thanks for you help.

Not sure what information you need to help, but I'm running a RC12L3.

Thanks in advance!

psbarger

iTrader: (3)

Check the outside wheel bearing, thats usually the part that makes the diff feel horrible.

Blakesrc

iTrader: (26)

Takt,

the diff on a 1/12th pan car is very very important and needs a lot of regular maintanance. If you are racing you should actually be cleaning everything and re-lubing it every 4 RUNS or so. You should try using some 600 grit wet/dry sandpaper to smooth out the rings, then re assemble. That is what i do and it makes a huge difference.

Have fun,

Blake

insideline

Get a big "D" ring diff setup from CRC

Get a full rear diff worth a super spin bearings from CRC (3 flanged and 2 unlanged)

Get some Associated white diff grease for the diff balls. Only one dot of grease on each ball.

Tighten careful and only enough to prevent the diff from slipping...

then enjoy!

rollover

If you have a local bearing supply warehouse you can pick up bearings and balls cheap enough to replace them every time you rebuild the diff.

dsrbltoys

iTrader: (1)

Look for the slapmaster bearing saver! It will redistribute the load to the outer race of the bearing, and not use this bearing as a side loaded thrust bearing. It also includes a thrust bearing to use with the spacer.

primusblowsgoat

iTrader: (14)

where do you get the slapmaster bearing saver at?

Slapmaster6000

iTrader: (16)

Ah ha... funny you should ask? I have been selling a thrust bearing kit to make 12th scale diffs lasts... dare I say it.... indefinitely. I have as a test, the same balls and plates that I purchased last Oct 2003 still in the car and they feel smooth as glass, and that's with a 10 turn. And that's all because of this thrust bearing on the outter hub. It's a fine balance between too tight to prevent slippage (which kills the balls and plates) and too loose to save the 1/4x3/8" bearing. It does not matter what diff grease is getting used, slippage still ends up with the same result. This kit has a sleeve that spans over the 1/4 x 3/8" bearing that removes it's side load and instead transfers that load into a purpose built thrust bearing. Then a cone washer and a metal nut. I recommend that you start out with a fresh set of carbides and a pair of ecconomy plates (D rings are best). Tighten the diff so that it does not slip under hard acceleration and you are done. Now, the only time I take the diff apart is to change the spur gear because it got damaged. The part is $30 but it is $$$ well spent. I have been stocking them at some local race shops in Wash & Ore. If you can not find them under the Slapmaster Tool header cards, then you can contact me at: [email protected] I am temporarly out of stock due to the popularity of them, but should have more in late this week or 1st part of the next. I don't have a website up yet, but it is around the corner.

Brian

taz5176

got any close up pics?

primusblowsgoat

iTrader: (14)

yes i too would like to see what it looks like

theisgroup

iTrader: (10)

me too.

2 week old 12l4 and had to change the bearing on the non spur side already. And was told that is not too unusual.

yang

litespeed-dom

iTrader: (4)

If I have time tonight, I'll post a pic of it apart, I need to clean my diff anway. it's well worth the $!!!

Dom

Slapmaster6000

iTrader: (16)

Oh Dom, you just think that you need to clean your diff. You bought a thrust bearing didn't you? Really, if you think that your diff is getting rough, you are not running it tight enough. The nice thing about this assembly is that you can still get your wheels on and off without taking things apart.

Brian

primusblowsgoat

iTrader: (14)

alright so in that pic what i am looking at?
you use your existing hub, you get a new nut, looks like some sort of spacer? and a spring or something? or i could be way off.

litespeed-dom

iTrader: (4)

Alright Brian, makes sense!

Here is what you are looking at..... 4 pieces total.