New CRC Gen Xi 12th car.....
12-19-2011, 10:24 AM
#406
As anyone run into a problem with the crc spur gears? I'm building my diff and can't get a smooth feel at all and I'm thinking the center of the spur that sticks out is little longer then the bearing and hubs are rubbing against plastic is all I can think of.
12-19-2011, 12:13 PM
#407
Yes that seems to be the prob. cause the diff in size between the 3/32 balls compared to the 1/8th also makes a diff. I am running it on my AE car with a IRS axle and slapmaster thrust and its perfect, best diff to date with this setups.. I gave a buddy a mine a crc gear to run and he didnt have the slapmaster setup and it would tighten all the way down. and when it did it would slip...
So then we thought it was the bearings cause im running cermics and a non flanged in the gear so i gave him that setup to try with the slap master same thing.
What ended up being the stock kit AE axle is different from say irs ae/speedmerchant/ect eventhough there from irs.. so how we fixed this we used his flanged bearings/crc gear/3/32 balls/than put the slap master black spacer with the flange down on the bering then ADDED another bearing shim to the other side to take up the room that its was missing and it came out silkiy smooth just like mine!
So then we thought it was the bearings cause im running cermics and a non flanged in the gear so i gave him that setup to try with the slap master same thing.
What ended up being the stock kit AE axle is different from say irs ae/speedmerchant/ect eventhough there from irs.. so how we fixed this we used his flanged bearings/crc gear/3/32 balls/than put the slap master black spacer with the flange down on the bering then ADDED another bearing shim to the other side to take up the room that its was missing and it came out silkiy smooth just like mine!
12-19-2011, 12:45 PM
#408
I had to run two axle shims between the bearing and the spacer when using the 72 tooth crc gear. As stated..the axle stub sticks out too far past the spacer when using the smaller balls. Blue Screws idea might work better,but I had the shims on hand.Feels pretty good to me and I have no slippage.
12-19-2011, 01:21 PM
#409
OK thanks guys I guess I'll keep messing with it and try to get it. It is rubbing on the axle hub so I shaved off the lip on the spur and used a flange bearing instead of a non flange bearing in the spur and seems to be alot more smoother.
Last edited by markiemark; 12-19-2011 at 01:41 PM.
12-19-2011, 02:13 PM
#410
Tech Master
iTrader: (47)
I just built mine yesterday and ran into the same problem. The kit is now coming with two additional 1/4" shims to put between the outside hub bearing and spacer. I rebuilt the thing four times and couldn't get it to my liking. Finally tossed it in favor of my old PRS 12-ball gear with ceramic balls and fresh RC4Less D-rings. Silky smooth.
12-19-2011, 03:31 PM
#412
Tech Master
iTrader: (6)
3/32 diff ball spurs
In an effort to clarify why some guys have trouble getting their diffs to work correctly when switching over to the new spurs with the smaller diff balls......the nut that is used to apply pressure to the outer bearing cannot be allowed to bottom out on the end of the graphite shaft before it has done its job of applying the desired side pressure onto the diff cone and in turn to the outer bearing. Since the new diff balls are smaller, they allow the whole outer diff hub to sit closer to the centerline of the car. On some axles, the grapite extends just far enough so that it reaches the inner surface of the diff nut before that nut's inner surface contacts the outer surface of the diff cone (the piece that actually touches the outer bearing). Thankfully the fix is an easy one. It's a simple matter of adding one or two shims on top of the outer bearing and under the diff cone. The thickness of those shims will take up the distance that has been lost by the smaller diameter of the new small diff balls. Once that potential clearance problem is solved, then the new spurs and the smaller diff balls work terrific. Having more diff balls will allow a smoother diff action because less pressure is needed on the diff cone to eliminate diff slippage.
12-19-2011, 04:22 PM
#414
I am willing to bet its the problem we posted about.
Build your diff as per instructions.
Now take a look at the axle end BEFORE you put the diff washer (cone spring) on. I am willing to bet its sticking out (or very close to) past the red outer spacer (the graphite end of the axle).The deal is the cone washer cannot put enough pressure on the diff because it hits the axle before it can put pressure on the spacer. Two shims in there fixed me right up.
12-19-2011, 08:05 PM
#419
16-Ball Spur Gears and Slapmaster Thrust Bearing Kits
A few months ago, Brian Bodine of Slapmaster Tools supplied me with two different sizes of his Thrust Bearing Kits to allow me to use the new 16-ball spur gears on my LE/Xi cars without using any additional spacers. I really like the smoothness of CRC 16-ball spurs combined with Slapmaster Thrust Bearings.
Contact Brian at www.slapmastertools.com for a professional solution to your issue.
Bill
Contact Brian at www.slapmastertools.com for a professional solution to your issue.
Bill
12-19-2011, 08:38 PM
#420
Since Bill chimed in, I have to follow. It's the rules.
I have found the clearance between the CRC hubs with the 3/32" balls/spur to rub on the inner flange on the spur. Simply take your Axacto and carve that little flange off the spur center and your bind issue will go away.
Since the balls are .032" thinner, if you are using one of my thrust kits, watch out for the thrust washer to bottom out into the end of the 1/4" axle. Sometimes there is a puddle of epoxy there you can carefully clean off. But you may need to go "up" one spacer to get the clearance back. You can not add 1/4" shims to my thrust kit. The delrin spacer needs to pick up only the outside race of the hub bearing in oder to work correctly.
And if anyone hasn't tried it yet, use the flat side of the grooved washer against the thrust bearing. It free's up considerably. The groove side has a bit of parasitic drag, but it will last forever, like 5 years. The flat side should last at least 3 years, awful, I know.
Darrell Skelton out of Portland gave me some carbide 3/32" balls to try. I built up two diffs last week and raced them all day Sat. Wow! Smooth, baby, smooth. At the start of the main in each car, I had to back off for the guy in front of me or I was going to run him over. Darrell can be looked up in the NW threads or you can PM me and I will give you his contact info.
Brian
I have found the clearance between the CRC hubs with the 3/32" balls/spur to rub on the inner flange on the spur. Simply take your Axacto and carve that little flange off the spur center and your bind issue will go away.
Since the balls are .032" thinner, if you are using one of my thrust kits, watch out for the thrust washer to bottom out into the end of the 1/4" axle. Sometimes there is a puddle of epoxy there you can carefully clean off. But you may need to go "up" one spacer to get the clearance back. You can not add 1/4" shims to my thrust kit. The delrin spacer needs to pick up only the outside race of the hub bearing in oder to work correctly.
And if anyone hasn't tried it yet, use the flat side of the grooved washer against the thrust bearing. It free's up considerably. The groove side has a bit of parasitic drag, but it will last forever, like 5 years. The flat side should last at least 3 years, awful, I know.
Darrell Skelton out of Portland gave me some carbide 3/32" balls to try. I built up two diffs last week and raced them all day Sat. Wow! Smooth, baby, smooth. At the start of the main in each car, I had to back off for the guy in front of me or I was going to run him over. Darrell can be looked up in the NW threads or you can PM me and I will give you his contact info.
Brian