Front Differential
 

One thing is for certain, my driving sucks! These trucks may need a little work, but they are a blast.

1 quart of fuel into it and I think I am having problems with the front differential. When you turn the front wheels, they turn smoothly for about 1 1/2 turns then it gets real rough for about 1/4 to 1/2 turn. Then it's smooth again. I ordered a replacement bevel gear (along with the center joint cup I lost the set screw out of), but could not find the differential gear. Has anyone ever replaced these before? I removed the drive shaft and am running it on 2WD until I get the gear thing straightened out.

These joint cups use a Metric 4 .4 set screw. Impossible to find around here. I found a M4 .6 and took it down on the grider for now. But I would prefer to use the right part.

Also, when I pull the front differential housing apart, will it be filled with an oil like 1:1 cars? If so, what do I need to put back in there?

Thanks.

RE: Front Differential
 

I'm a little confused with your description... are the wheels binding after the front set screw was gone or before? The bevel gear is pretty difficult to break so I'm more inclined to believe thats its the internal diff gears... They are made of a soft metal thats easy to break.. also, the diff carrier is pretty fragile also... these are more likely the problems...When your new center cup comes in, it should include the set screw... they are 4-40 set screws... look for them in the dubro section of the hobby store.. lastly, the diffs don't use fluid, they are filled with regular grease... just use one that sticks to gears.. automotive grease will fly off the gears.. tamiya makes a good one..