leongkc

iTrader: (9)

Does a noisy gearbox indicates the pinion to the bevel gear is broken?

HeavyD99

iTrader: (15)

Possibly. Only way to know is to take it apart and see.

leongkc

iTrader: (9)

Just did that....

The bevel gear and the pinion on it all seem fine.
On power on the car stand, there is no noise. Only at the track, I can hear the chattering....

Do I have to take apart the diffs too to check the gears inside? Turning the outdrives by hand, nothing seems to be out of the ordinary.

Odin544

iTrader: (93)

more than likely its the gears inside the diff. Under load they are probably skipping teeth. Better open it up and find out.

gdw1963

Noise on acceleration probalbly the rear bevel or 35T diff gear, noise on breaking probably the front gears. Check them thoroughly, one teeth could be damaged just a little... If that's the case, loosen the slipper.... (and check the gear mesh, if there is to much play, shim the gears properly).

Also check the cvd pins from the centre axles front and rear. Sometimes they force them self through the plastic drivecup. If that's the case lubricate enough with black grease ore buy aluminium ones.

joeymdz

iTrader: (13)

My gear box started to make noise yesterday. It wasn't bad but wasn't good. Opened up the front and rear bulkhead blocks and found 2 small fragments from the bevel drive gear in the front one only (you will find black dust or chunks inside the bulkhead). Replaced it and no more grinding noise. It was literally only missing 1/2 a tooth. Problems when you buy a used car I guess but a simple fix.

Ps- when trying to extract the bevel 14t gear use one of the 3x14mm screws. You can thread the screw about 1/2 a turn into the front of the bevel gear and pull it out... allot easier than pulling everything out.

mjk1210

iTrader: (9)

Check inside the diffs. If all seems good there too then Check that it isnt the esc/motor cogging a bit when u pull the trigger. A bad sensor connection can sometimes sound a little like a crackling gear. A little bit anyway.

asc6000

iTrader: (15)

You toasted the spiders in the diff, one or both. Take a good look and if they look good you may be able to save them with a shimming. Or... replace them with new gears, v2 advised or NT1 metal. Depending on which combination you use the shimming will need to be checked. This is not a perfect world, a little attention is all it needs.

Hoyle

Hello Fellow XB4 owners,

I have a question to ask of the forum it is in regards to my XB4 which I build a few months ago and have only run in my backyard on grass as a test.
I noticed the other day oil pooling on the chassis and investigated, it appears to be concentrated on a couple a screws on the chassis below the front and rear differentials (please see attached pictures). I assume oil is leaking from the differentials for some reason.
I am unsure of the cause of this or how to fix it and would appreciate some help to trouble shot this problem. My apologies this is the first car kit I have constructed and I'm new to the hobby.

Regards,

Matthew.

001casey

iTrader: (31)

Did you use the blue gaskets when you built the diffs? Or maybe over fill with oil or maybe over tighten the 4 small diff screws? Was there anything left over from the packet when you built the diffs? Maybe look again at the build instruction manual in case you missed a step.

GSM Storm

iTrader: (114)

Hi Matthew

This is what I do when building the diffs
I use a automotive CV joint grease on the "O" rings and Tamiya anti ware grease on both side of the gasket, never had a diff leak ever, been building gear diffs this way for years.

Regards
Gary

GSM Storm

iTrader: (114)

Thanks Daniel, that was close to were I was going to start, I am going to have a run in stock with one of my son's XB4's, what spur are you using, AE drilled out ?, I have a 72T RW spur from a Schumacher, was going to make a spacer from 8mm to 6mm on the lathe tomorrow.

Regards
Gary

Hoyle

Thanks for the reply's. I'm pretty sure I filled with the correct amount of oil since I used a Pharmacy scale that is accurate to 0.01g to measure the amount of oil in the diffs and followed the instruction manuals suggested weight. Although I thought that the amount of oil that the manual suggested to add seems like alot, perhaps they are overfilled. I had no parts missing when I finished building the diffs its really weird. I will have to get the diffs out of their housings and see where the differentials are leaking from I guess. Thanks.

001casey

iTrader: (31)

Build them again and wipe off any excess oil with a rag. Let them sit for a few hours before putting them back in the gear case. Any leaks should show up better this way.

Hoyle

Excellent idea. Thanks.