1fastPIRATE

iTrader: (10)

I know there a good amount of threads out there on building ball diffs, but I want some personal experience on what works best for you, and why.
if at all possible maybe some insight on the cars im currently running...
im running the b5/b5m, and the b44.2
the b44 is the one im having the most problems with..im making it one race day before the diffs are trash,
the b5 and b5m are doing ok I think, they last about 5 race days before they get even a little gritty the b5 used carbide balls and still feels a lot better than the b5m with steel..
so I just ordered some grade 5 ceramic balls, I was planning on getting b fast diff rings and some sort of caged thrust bearings..
what are yalls thoughts on the caged thrust bearings? what do yall use to get your diffs silky smooth for along time?

Justinb86

My guess is you are either running it too loose and slipping it on the landings or you overtightened it when breaking it in.

I know I didn't realize I was running on the loose side till my pit buddy helped rebuild my diff in the middle of a race. That diff lasted a very long time. Another issue I had was that nobody ever mentioned that you can't loosen your diff very far at all with out loosening it way down and retightening it. I'm certain that cost me a few diffs. Since I had help building a diff all of mine have lasted way longer. At least double if not tripple what they used to last.

Get someone at the track to help you rebuild the b44 diffs. Even if u have to do all the prep work and have it laid out and ready to assemble so u don't waste there time. Could definitely help.

I don't run ceramic diff balls. Too much chance to get your settings wrong. Very narrow window for the correct adjustments. I do run the ceramic caged thrust assemblies. They work great.

1fastPIRATE

iTrader: (10)

I see your point on getting help from some of the guys at the track, tho im leary in doing that, I hear so many different things from people sometimes (do this, no don't listen to him do that) and the one person I know that runs a b44 a lot and is fast has had some trouble breaking different things maybe bad luck, but I know he broke a rear ring gear, so id be leary to ask him as well(not to mention he is kind of a d!(&. ) I love learning (sometimes I really learn the most when its the hard way) so im gonna try to do this one more time by myself..(with rctechs help of course!)
I watched a video of an olderish guy building b44 diffs and I followed what he said pretty darn close..
when running b fast rings is there any need to sand them?
how do you tell whats to tight?

ive not yet heard of this care to take that a little deeper?

skeasor

If my diff get's too loose and starts barking I'll rebuild it. I usually rebuild mine once a month just to make sure it's smooth but that may be overkill since most times it doesn't need to be rebuilt. But I think after 5 race days the diff should probably be rebuilt anyway.

1fastPIRATE

iTrader: (10)

ive yet to hear mine bark, at least not in the last few times ive built it, im hoping my problem is the quality of the steel balls, I know when I switched the b5r to carbide the diff was a lot smoother instantly, as well as after 5 race days you can tell it isn't brand new but not near as bad as the steel ball b5m diff, the only diff I cant get to last is the
b44, after almost 3 packs It feels pretty bad, im really hoping its quality of balls.

Mustrum

Mines are butter smooth, ceramic everywhere, rgp grease for balls, and schumacher black grease for thrust without cage.
Sand the shims a bit so that balls grip whith a soft tighting of the diff.

ThePanda

iTrader: (68)

Check this out- http://www.rctech.net/forum/electric...er-clutch.html

Remember to break it in and check every few first runs on a new diff. There are a lot of helpful videos on YouTube. Most with decent view counts and high ratings are pretty good.

rcjunky1

iTrader: (10)

And don't sand bfast diff rings, all those rings are is factory rings that they sand for you

skeasor

I've never sanded my diff rings before. Is there a real benefit to it or is it mind over matter?

Bubonic-X

iTrader: (4)

do everything the manual tells you but heres the key... As it says tighten all the way and back it off i cant remember how turns. just follow those directions. Next take 2 wrenches and slip them in the slots of the outdrives. this is so the outdrives do not move. Now take a towel so that you can grab the diff gear and try to spin it. Use all your strentgh to do this if you cant move the gear its too tight. back the screw off maybe a eighth at a time, keep doing the same process till you can make the gear slip. Once it slips its on the edge of were it needs to be. Tighten back maybe an eighth of of turn until the you cant make the gear slip again. Your done!
You must remember that the diff when you spin it in your hands ( not installed in car ) back and forth will feel slighty gritty. This is normal. I gaurantee when you install the diff back in the car and turn the wheels back and forth it will feel smooth as butter.
Now to make sure the setting is ok in the car turn on your car and radio....take your forearm and rest it across both rear tires and tap the throttle a couple times while you have your forearm across the rear tires. Dont hold the throttle just blip it.. What your looking for is the cars front wheels to rise a couple inches and most importantly the diff does not bark and slip. If it barks/slips tighten diff an eighth of a turn. Try again till the diff is quiet and the tires lift.

Try on track and make sure your slipper slips before the diff does and you should be golden. I dont race that much so I can get 4 to 6 months on mine before a rebuild. Use all stock parts they work fine.

That is my way of doing it. it has worked for me for 25 years.
But guys if you want to add or correct anything I have said by all means chime in.
Jake

skeasor

I can never get my wheels to lift but I am only running a 13.5

1fastPIRATE

iTrader: (10)

I know ive read this before, but i must have skimmed it because there are things i havnt tried in it, im gonna order some caged thrust balls now...

And is rcjunky1 right? Are they just pre sanded stockers? If so id really prefer to sand my own stockers..

The diff balls ill be using are bulk ordered ceramics from ebay they claim to be grade 5, anyone have any opinoins on these? I know they arnt grade 3 but couldnt justify the price of the grade3 i found

samnelso

iTrader: (1)

A smooth diff is one of the most important factors in a car's handling. I'm not sure how many vehicles you're outfitting here, but good ceramics aren't too expensive in the long run. They last forever.

Castellano has a good diff build video. It's basically how I do it, especially with the break in procedure he does. Takes a while to get the diff setting right, but then you're good to go. The diff may then loosen a bit after the first run, so it should again be checked, especially if you're using brand new rings.

+ YouTube Video

1fastPIRATE

iTrader: (10)

I understand totally how important the diff is that's why im trying to get mine butter smooth for longer..
ive got 3 cars with ball diffs, one car with 2 diffs, so 4 diffs total
ive got more cars than that, honestly to many to keep up with maintenance, another reason for this thread..

in some peoples eyes $1 for 1 grade 3 ball isn't much, but that would mean $52 in just diff balls, then I need thrust balls and rings for for 4 diffs...it adds up quick..so 25 bucks for 100 grade 5 ceramics I thought was a good deal, we soon will find out.. does any one have any personal experience with said grade 5 ebay diff balls?

samnelso

iTrader: (1)

Looks like Boca and Acer use G5 Si3N4, so they're probably OK.