XRAY - Model racing cars

Hi,

I drive my 808e since April now without any issues. I started with diff oils 20K/10K/10K as the kit suggests.

About 4 weeks ago, I changed to 10/7/5. Some days later, front diff bevel gear broke, see picture below.

I bought another one, but after 3 racing days, it broke again, lost a tooth like the first one seen in the picture.

So, what's wrong? It has run 5 months without any issues, so I don't believe in any faults from the assembling like shimming/spacing and so on.

I don't want to buy a third diff bevel gear because I believe it may brake, too. Loss of trust or so

Any help is appreciated!

Greetings
Sven

I had the same problem. I've 3 new diffs so I don't worry for a long time

I think I know what the problem is. Shim. I didn't shim good and my diff was damaged. Now I shimmed it very well and there is no problem. You have to shim many times. Then is your diff very good and you don't have that problem anymore.

Sorry for my bad english

I agree with Bryan. You should put shims on each side of the bearings to adjust the mesh. It's abnormal that the teeth got ripped like this! Especially on the electric version of cars, there is so much power you have to be very careful with shimming. I advise to use minimal play, it has to be free but with minimum play. Maybe also you have Reverse set? It could be very rough for the gears...

Hi Reno and Bryan,

thanks for the response.

I doublechecked the mesh several times, it as minimum play. From my point of view, the play is perfect.

What I don't understand: It worked well for months, and suddenly two gears broke within a week or so.

I have reverse, but it's only possible to use it after the car stops. So no reverse at full speed .

The current gear is fine since 8 weeks now. Maybe just bad luck? I don't want to invest more money into the 808e, expecting the xb9e in 2013

Greetings
Sven

I don't know what happened then..Maybe it was her time

Best regards
Reno