peter_robinson

iTrader: (21)

Flanged

Highside20

iTrader: (2)

Thank you!

sprintcarracer

iTrader: (26)

Since my ball diff building skills are very poor I'm looking for help. I start with 400 grit and work my way up to 1200 grit. The rings look very nice and flat but not polished just faint cross hatch marks. But when I assemble the diff it is not smooth but fella very thight. I just can't seem to get that silky smooth spin that everyone else gets. I'm just wondering how others build there diffs. I have hours into one now and I think I would be better off just installing new untouched rings and running the car that way.

xtrememadness

iTrader: (2)

Hey josh did you add those 10r5 chassis to the speedshop? Cant seem to find it. Thanx

wingracer

iTrader: (24)

The balls and rings are not the only place crunchiness can come from. Replace your outer bearing in the hub or get go to a thrust bearing.

Did you replace the balls? Steel or ceramic?

JamesL_71

iTrader: (13)

This. When I rebuild my diffs, I *always* test them out with a brand new outer bearing. Then I retest with my previously used outer bearing and compare the smoothness. That should give you a good indication of whether or not it is time to replace.


Also, I sand with much higher than 1200grit for the final step. I go 400, 600, 1200, 2000.

Something else that some people tend to overlook, is which side of the rings you choose to prep. The diff rings develop high spots, obviously... this is why we sand/prep them. But some rings develop the high spots toward the outer edge, others develop them towards the inner center. When I am prepping new rings, I always *lightly* sand both sides on a *perfectly* flat surface. Then carefully inspect both sides... you will see a slightly scratched/shiney surface starting to appear, which is where the sandpaper has removed material from the surface of the diff ring. The side you want to continue prepping will be the side where the scratched/shiney surface is developing towards the outer edge of the ring.

sprintcarracer

iTrader: (26)

All of the bearings are good. I replaced the balls and they are steel. Where can I get a thrust bearing and do you sand those rings just like the diff.

burgboyz

iTrader: (70)

I like these...
http://www.slapmastertools.com/thrust-bearings.php

Josh Cyrul

iTrader: (1)

Sorry guys, been down sick the past few days.

Diff - I never, ever sand rings. Unless they are horrible there really isn't reason to build a good diff. To me, there are a few critical things to a good diff:

#1- Good outside bearing. I don't like the thrust bearings and only recommend them if you crash a lot. At $1.00 each on our shopping site, no reason for expensive thrust that in my opinion doesn't build any better of a diff.

#2- Ceramic balls to me are a must. They are more round, won't flat spot and I've run the same sets for over 2-3yrs. Also, when building my diff I leave it loose and hold 1 tire + spur and crank other tire - makes a squeaking sound but super hard ceramic balls actually cut the groove into the rings making sanding rings a waste of time.

#3- Only use AE diff grease w red writing - again sold on CEFX site. This grease has perfect mix of abrasive so diff doesn't slip, is smooth and is super free.

#4- Spur is critical. I haven't tried some of the new CRC or Xenon gears but the only spur you will ever see in my cars w diff is kimbrough. Honestly, most other spurs (machined) build terrible diffs.

sprintcarracer

iTrader: (26)

Thanks Josh. I will pick up new diff bearings and new rings, I have the cramic balls.

Highside20

iTrader: (2)

Hello Josh,

What is your deadline for placing Z4 tire order for nats?

Thanks!

JamesL_71

iTrader: (13)

Looking forward to trying out the Z4s on my 12th

Xpress

iTrader: (3)

Anybody have any experience with the CEFX Xray chassis?

peter_robinson

iTrader: (21)

+1 to this. All I use is Kimbrough as well. It's impossible to have a great diff without one.

Xpress

iTrader: (3)

Anybody know if Josh is out of town racing? Placed an order for an "in stock" item Monday and haven't received shipping info yet?

Thanks