Losi XX CR Issues

[Jcgonzal]

Hey everyone, just joined the site after recently acquiring my first hobby grade RC car. I’ve dabbled in RC aircraft, but never cars. I was probably naive buying a cheap old RC car, thinking it’d give me at least a few runs trouble free. My XX is in pretty rough shape; seems to have been neglected, lots of rusty hardware and worn out bits. My first time running the car was fast and fun...for about 5 min. The spur gear stripped, ending my fun rather abruptly. I think I attributed it to the slipper being completely cranked down, plus I haven’t checked the mesh between the gears.

So long story short, here’s my problem. The two diff halfs were worn out, with the slots being obround where the axles make contact. I found a manual online, found the part # for the diff halfs, and ordered two up that I found on eBay. The new ones don’t match the old, other than overall dimensions. I don’t know if I ordered the wrong parts, or if maybe this diff isn’t original...I just don’t know enough about this car yet. Can anyone shed some light on where I can go from here? I managed to damage the original diff halfs (more), so just putting it back together won’t cut it.

Pics of old vs new (Gold is old, Black is new)

[Jcgonzal]

And here are a few pics of the old girl, I know most forums love pics

[clintf]

I don't have much insight on your issue, but I would probably just rebuild the entire diff with new parts if available (and according to the parts #s in the XX-CR manual). Just looking at the state of the outdrives it's been pushed real hard and I'm guessing not setup right. Might want to take a look at the other side of the drive shafts/CVDs and make sure those are in OK shape in case something is binding during use.

[jwscab]

the original worn out drives are aluminum, not sure if it was a losi upgrade or an aftermarket one. either way, not really intended to last very long, more of a super stock type application. the bone pins should show very little wear, that's a good thing.

the new ones appear to be steel and the correct parts for your build, should last a good long time.

[matt1ptkn]

Looks to me like you just need a Diff Tube (A-3072) and a new 5mm x 8mm Bearing (A-6907) and you should be all set. www.sabulatech.com has both in stock.

[Jcgonzal]

Looks to me like you just need a Diff Tube (A-3072) and a new 5mm x 8mm Bearing (A-6907) and you should be all set. www.sabulatech.com has both in stock.

Awesome, thanks! Got those ordered up, I’m excited to get this thing running again.

Love your Andy Bernard quote, by the way.