# SC10 4x4 Diff Issues



## Ronborsk (Jan 28, 2006)

Background. My brother, his son, and I purchased 2wd SC10's and 2 of them had diffs go bad so we rebuilt them with an added shim under the sun gear with no problems as of yet. Hope this fixes it.

I also have a SC10 4x4 and after about 5 or 6 runs have already ruined a diff gear. So, what is wrong with my set up that is causing this? Has anyone else had problems with AE diffs in the SC10's, either 2wd or 4wd?

Ideas as they enter my mind, not thinking one over the other, etc:

1. I believe that I filled the diff all the way to the top with 5k diff oil, Should I have stopped at the top of the metal shafts that cross? Not sure what the adverse effects of overfilling.

2. Slipper too tight? It doesn't seem to slip but boy that slipper area seems to get pretty hot as did my motor. (running Castle 3800 4 pole 32 pitch stock spur with 15 tooth pinion, oh... and how hot? Didn't want to say or admit it but 195). Also brings to mind a question of whether or not my belt can be too tight bringing up temps of motor.

3. Can my braking need adjustment? Does slamming on the brakes cause too much stress on it?

4. Combination of too tight slipper and too much punch from the motor? Need to tone it down??


My guess is that I need to do a combination of things. Would love to hear your input. By the way, haven't been racing here lately even though I live in Spring. Racing in Bryan Texas because I have have family that also races there.


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## monsterslash (Aug 4, 2010)

I have a SC10 4X4 and have the same setup as you do and my temps never get over 145 and esc 120 the belts could be to tight have made that mistake and it cost me some bearings.


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## cjtamu (Sep 22, 2004)

The diff issue on the 2wd is well known. The original shims were too thin. The added shim should fix it. Don't know much about the 4wd, but if you're running the same setup as Lance, your temps shouldn't be that different. If teh belt is too tight it could certainly cause some drag. Too tight slipper wouldn't account for a hot motor, but could definitely eat diff gears. How's the racing in Bryan? Haven't been there since last year. Is Kevin Bard still racing?


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## Ronborsk (Jan 28, 2006)

*Diff and racing*

Don't know a lot of folks names out there. They also don't do printouts between races so it is difficult to learn names.

There was a pretty light crowd last Saturday night but it sure was nice racing in the evening and after dark. They did, however, have 9 in the 4wd SC class and I believe 6 in the 2wd SC class. Although they don't have the first rate accomodations that other local tracks have the racing reminds me of old time club racing at road runner. Since last year they have expanded the track a bit with wider lanes and just a bigger track overall. The track is quite loose, not packed. 2wd's can get stuck going up a hill and bury itself to the axles. All in all still fun. They rented some lights (or someone supplied them) for the race so visibility was good.

I've keyed the diff problems to death through google and have read all of the things about the 2wd. Hope to figure my issue out. May not have the problem again after rebuilding and since I added shock limiters. Also thinking I can bring the temps down by making sure there is no binding, belt is not too tight, as well as adding a vented slipper.


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## cjtamu (Sep 22, 2004)

Don't know what s[eedo you're running, but that's a possible culprit. The ones where you can set timing advance, punch, boost, turbo, etc. can get you in trouble if not programmed properly.


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