Upgrading sb401 gearboxes

[cheapskate]

Apart from the gearboxes and bearings, is there anything else needed to upgrade the gearboxes on the sb401

[tonydevon]

nope thats it

I put so much time and effort into the original setup, that it was quieter than others, did the swap and didnt notice a huge difference LOL

order the bearings from a bearing supplier as the PR packed ones are a bomb

[cheapskate]

How much lash should there be between the pinion and crown gear?
I checked the diffs the other night and there was quite a lot of movement on the diffs

[Top Dollar]

As a guide I look for a little movement, somewhat like the pinion and spur gear. On our 401 gearboxes I have two shims the gear side and one/none the other, plus one behind the crown gear. That works for us. Check the mesh on yours to see how snug it is and adjust as needed

[tonydevon]

I just went back to my manual, thats where I make build notes, and I have the same 2 shims gear side and one behind the input gear

I had only raced it indoors and really noticed the noise, ran it outside on Sunday for first time ever, and couldnt hear anything different to other 4wd buggies