Shredded rear crown gear in B44!
 

Hello Chaps

Had a great days racing today. Unfortunately after the final, I noticed that that the teeth on the rear crown gear and pinion (within the rear gearbox) had shredded. This has happened once before.

The slipper wasn't too tight, and the gears were shimmed as per manual.

Anybody else had similar issues?

Also on a side note for those using Lipo, have you benefitted from extra weight? If so, where about on the chassis have you placed it?

Thanks.

Had the same problem as you, it happened to me almos every two races. Tried everything, loose slipper, reshiming etc. At the end it was the gearbox, wich was default. Change it, maybe it is the same for you.

Cheers,

I had the same problem on my car on both ends. I changed the gearbox housings but no luck, the problem was still there.
It appears that my car needs more shims than stock. I had to add 2 or 3 shims on the diff to stop lateral play and I don't have any breakage since.

So shimmage is the way to go :thumbsup:

Manuals are only an indication, you should always make sure your gears are shimmed properly, with minimum amount of play and no tight spots. This is true for any shaft car.

Same here 1 pair of rear gears per 2 races today!!!

WHY!!!!:mad:

I did some rear gears today. They had done around 5 or 6 hours of running so wasnt too bothered. Make sure that you mesh them tightish! I think ive got 7 shims on the long outdrive side :blush: and 4 on the other. Also make sure that when you change the gears you clean the gearbox casing out of any dirt!

BJ

Alright Bud

Yeah well the first pair today that went had been in ages!!!!!!!!!!!!!!!!

Ive got just factory so i think its 3 (short) and 4 (long)

When you say tight how are you checking the tightness etc.

Thanks bud

I would say that the mesh will be too loose with 3 and 4 shims. Try what im running and see what the backlash is like.

A rough guide to setting all shaft drive gearboxes is

keep adding shims until all lateral movement of the diff is eliminated
starting with all shims on long outdrive put diff in gearbox and check backlash
move shims onto short outdrive checking backlash each time
once all backlash is removed transfer thinest shim available back onto long outdrive

it is also worth checking the movement of the pinion gear as this might also require shims

What is backlash?

Slight movement between the gears, you should have some between motor pinion and spur as well!

HTH