Who's the diff daddy??

[Pops]

Can someone give me some tips on building a diff that lasts more than one event without becoming coarse and notchy? How often do you guys rebuild? Which diff balls are best..I use the std carbide ones, sand diff rings on a flat granite bed with 1000 grade wet/dry using a spot of wd40.When first assembled the diff is really smooth and i get that oooh feeling when i turn it!!! After a qualifier or 2 its slightly course and after finals it feels nasty so i do it all again(2 x6's and a b44!) Heeelp please
Thanks, Dave

[MiCk B.]

Hey,

Do you clean the WD40 off the rings?

MiCk B. :-)

[sosidge]

Don't forget to give the thrust bearing equally good attention! Round balls, flat plates, thoroughly cleaned, then well lubed with black grease.

[Pops]

Yeah i clean every thing before i use assiciated diff lube on rings and balls and black grease on thrust balls.. when i strip down the diff rings have a groove in them but its not worn smooth, its like the groove is lumpy!! and thats what gives the notchy feel

[sosidge]

If the rings are wearing unevenly, that suggests that something is not running true in the diff. Are you saying it is happening in all of your diffs? If so I wonder whether something about your tools or technique for sanding the rings is making them come out wrong.

Personally I have never sanded a diff ring in my life - even some of the superficially ropy ones - and I have always had long-lasting, satisfactorily smooth diffs. Whatever surface prep you do to the diff plate is worn away once the diff beds in after those first couple of runs.

[YoungChazz]

There have been some problems with AE diffs of late. It cost Ellis the win at the last race.

Check that the two diff bearings fit properly into the outdrive and gear. It should "float" easily into the outdrive, not "pop." And it should press smoothly and easily into the gear, again with no "pop." If you must apply any pressure at all to get the bearings in, relieve the hole where they go. Don't let either one become sloppy -- it's a bearing and it must fit properly -- but these are small bearings and it doesn't take much to deform the outer race. Premature and uneven wear can easily be the result.

[Pops]

Originally Posted by YoungChazz

There have been some problems with AE diffs of late. It cost Ellis the win at the last race.

Check that the two diff bearings fit properly into the outdrive and gear. It should "float" easily into the outdrive, not "pop." And it should press smoothly and easily into the gear, again with no "pop." If you must apply any pressure at all to get the bearings in, relieve the hole where they go. Don't let either one become sloppy -- it's a bearing and it must fit properly -- but these are small bearings and it doesn't take much to deform the outer race. Premature and uneven wear can easily be the result.

Going to run the cars(all rebuilt diffs) tomorow and check them after racing. I think the bearings or some thing is misaligned as you have said. As the parts have done a fair bit of work now i'l change the lot this week... Darren wil sort me out no doubt!
Have any of you guys run the geared diff in the x6??

[Paul_Sinclair]

Hey Pops - what kind of break-in procedure do you use? It's important to 'break in' a ball diff, then re-tighten it before your car actually hits the track. During break in the balls and rings actually wear in together and the diff gets looser; forgetting this would lead to results like you describe, as the diff would be too loose though much of your racing and pretty well junk by the end of a race day.

I run standard carbide steel diff balls (X Factory #6500 ) and diff rings/thrust bearing from B-Fast RC (http://www.bfastrc.com/). The diff in my X - 6 Squared lasts a good 3 or 4 months of twice-a-week racing plus additional practice. I use the break-in procedure described in our K021 manual, found on page two here: http://www.xfactoryrc.com/rc/pdfs/K021-12-RacePrep.pdf

Nobody I'm aware of has tried a gear diff in an X - 6 or X - 6 Squared; the AE gear diff is larger and wider than the standard ball diff, so you need a larger transmission case. Because of the way the X Factory transmission fits in the chassis, it would really require quite a bit of work to fit it in. Finally, in general gear diffs haven't seemed to really catch on in 2wd cars for competition. I know several other teams and individual drivers who have done extensive testing with gear diffs, only to conclude that the ball diffs were faster and more consistent overall.

Hope that helps!

[Pops]

Thanks for the info and links Paul

Will try a fresh rebuild and the running in method..

[ant west 71]

hey dave, get yourself a cougar, lol..
see u on the weekend mate.

[Pops]

Originally Posted by ant west 71

hey dave, get yourself a cougar, lol..
see u on the weekend mate.

WE are at Silverstone this weekend and at cov the week after..
Changed the diff internal and outer bearings and used new diff rings plus a set of lazy ceramic diff balls in each of the x6's and they are both sorted!

[ant west 71]

get yourself up talywain, should be a good weekend.