paraletic

iTrader: (13)

My rear diff-dust covers seem to scrape on the rear bearing cap when rotated
in the manual it shows a distinct gap between the two after assembly yet mine didn't seem hav that
I've checked 3 times an the bearing shim is in place

any ideas?

Also the drive train doesn't seem very "free"
I havnt ran it yet - no elecs in it yet - plus it's not finished
will it loosen up after a few runs?
Front belt seemed excesivly tight on kit settings so I've loosened it up by rotating diff cams
this seemed a tad better on the freeness of drive train but still very stiff/tight

Bishop

iTrader: (5)

Pull apart the ball diff and flip the plastic pulley, in theory it's suposed to be symmetrical but in practice it's been punched out of a mold at some point, creating a bias to one side, I have the same issue and took a closer look, flipping mine and no more rub.

You may want to check a few things, shimming of the center spur being one, they changed the pin design so the plastic shims are now too thick, remove one and replace with some thin metal shims, also make sure to actually shim it dead center as well, takes some trial and error but that also stops the spur gear pulleys from rubbing on the top deck as well.

And yeah front belt seems tight on stock cam setting, I also set mine looser, just small details like that and mine was very free once sorted.

paraletic

iTrader: (13)

Cheers
was almost tempted to put both bearing shims on the diff pulley side
I'll flip the pulley tommorrow

yea I noticed the spur pullies ran very close to top deck was gonna take a file to the deck

yea I took one shim off an fitted with just one so maybe I need to recheck the shimming - I left no shim on the side with the "leg" of the shaft an one kit shim on the otherside, will check that also

thanks for input

stiltskin

iTrader: (103)

Couple of things on the center pulley. Make sure that the bearings are completely seated in the housing. It may LOOK like it is, but not be fully seated. That will definitely tighten up the drivetrain. I also filed the top deck a little bit to prevent any rubbing and ease in the removal and replacement of the pulley. For the diffs: make sure that both bearing caps are pointed in the same direction and they are fully seated in the notch. If the camber link plates are hard to put on, STOP and check the caps. Don't force them on. If you're still having issues, let us know. The drivetrain will wear in, but it shouldn't be tight.

MikeXray

iTrader: (73)

Tony, did your gear diffs free up after some use? I just got mine, part of me wants to use some old school diff breakin techniques, part of me wants to just run it

stiltskin

iTrader: (103)

Hey Mike. I've only got about 20-30 minutes on mine. We've been working on the track and I haven't had any time to run the car. It did wear in a little bit in that time.

Tenkuro

What kind of techniques do you use to break in the car?

MikeXray

iTrader: (73)

We used to use a mild abrasive for plastic gears, not sure if it works on metal.

paraletic

iTrader: (13)

When u say about the bearing cams(diff) fully seated and ease of fitting camber plates....

My camber plates had approx 0.5-1mm gap between the bulkheads and the bearing cams/caps
should the have been flush? I tried pushin them in further an checked but that was bout as good as it got

I'll give the topdeck a kiss with the file I think then double check the spur/pulley setup
also flip diff pulley

Tenkuro

Cool. Can I get the name of the specific abrasive you use? I always thought that breaking in something means using it. I didn't know you had to use other products to break it in.

vabroom

When I was racing nitro wwaayy back in the 80's, we used toothpaste to lap/break-in a new engine or a rebuilded one. Even ran it on the track with the toothpaste and fuel for one tank to help break-in the engine. Toothpaste probably help break-in the gear diff. Break-in by holding one wheel and slowing applying power to 1/3-1/2 throttle for 30 seconds, repeat on the other side just like breaking in a ball diff.

dbmartin

iTrader: (11)

Do any retailers in the US have the gear diff?

Does Top USA offer them and if so, how do I order it.

Thanks.

stiltskin

iTrader: (103)

TOP USA offers them. Call them or send them an email to place the order.

stiltskin

iTrader: (103)

I'm talking about the notch in the bottom of the bearing cam, where it sits on the tab of the bulkhead. I've seen these not fully seated and even though the camber plate won't seat properly, the guy just cranked the screws down and deformed the bearing cam. It really binds the drivetrain.
If the bearings on the center pulley are not seated fully, it will also put alot of drag on the drivetrain.

AdamD

iTrader: (6)

Just give Michael a call at TOP Racing USA I'm sure he can hook you up with a gear diff. 650-583-8898.