Losi 8ight notchy gearbox

[gps3300]

Rear gearbox on my 8ight gets really tight & almost locks up at one particular point when turned by hand.

If I back off the LHS gearbox clamping screws off a few turns it frees up

Can't see anything wrong with the gear teeth on the crown or the pinion gears even on close inspection.

Gears are almost new, no wear. Car has had approx 10 runs. All I can think is the diff crown wheel is doesn't screw down evenly onto the diff casing making a "high" point? This gearbox is particularly noisy.

Anyone else ever had a similar problem?

[jimmiprice]

Hi mate,
Is the car a new 2.0 model or one of the original 8ights ?
If its a 2.0 it will probably be the shimming on the rear diff that needs setting up.
If its a 1.0 model it may well be something i have had a problem with in the past. Last year at one of the nationals i melted the rear gearbox in one of my losi truggys. This was pretty extreme but you may of done something milder still causing some distortion.
If your confident the pinion and crownwheel along with the associated bearings are good check the four bolts that bolt the crownwheel on to the diff case are tightened down evenly. Build it back up and if thats still no good bite the bullet and buy a new diff case and gearbox case, only a tenner and that should sort it out. As i would guess for some reason the back of the car has been hot and something is out of line. If the car is a 2.0 and the shimming doesnt fix the diff problem do the same as ive said for the 1.0 car. Let me know how you get on.
Jimmi......

[gramey]

Have you fitted the Losi alloy diff supports in place of the stock plastic ones? Although the normal recommendation is that you don't heed to fit these until you've put a least a gallon through it I've fitted them to my 3 8T 1.0's from new and never had a problem with the rear diff binding or locking.

[gps3300]

Cheers for the advice. It's a 1.0 with standard diff supports. It does look like the case has distorted - I'll try a new one.

Thanks,

Ian