How often? Diff rebuilds.

[The Chef]

I have a B44 that I purchaced secondhand and was wondering how often I should rebuild the diffs or at least check them. As I bought it second hand and didn't build it it feels a little strange so any advice would be great thanks you.

[mpg200]

I bought mine second hand too. The best thing to do is rebuild them when they feel 'gritty' , they should run smooth, just check the tightness,not too loose. In general I rebuild because need to change the gears.

[RoyalCBR]

I have just done my front and rear diffs on my B44 for the first time.

My B44 was second hand as well - looked up 'how to' online, this is a useful vid:

http://www.petitrc.com/setup/associa...ips/index.html

Try the 2nd and 3rd video.

In the end quite easy - I need to upgrade by diff balls as well to some nice shiny ceramic ones

[smarkham]

I just re buildmine when they feel gritty as above. The first re build you can just turn the rings around and just replace the balls. Well worth going ceramic ball route with minimal diff grease just enough to hold the balls in place and loads of the black thrust grease on the thrust balls.

[The Chef]

Front diff gone stripped. Now rebuilt and better

[buhade]

Do not use ceramic balls, there surface is to flat, its only for scale racing. the ball must cut in the diff rings.

[bigred5765]

all schumacher off road cars run ceramics,

[mattybucks]

I also use silicone nitride diff ball in both my tamiya's. If fact I think if you were go to a track today the majority if people would be running them.

Why do you say not to run them?

[Col]

Originally Posted by bigred5765

...schumacher...

Originally Posted by mattybucks

...tamiya's...

Bugger off, you two! This is the associated section!

[buhade]

The wheels in offroad are bigger - so more torque on acceleration is on wheel.

The tungsten nitrid ones are more cutting the diff rings and so its more grippy - that i was told from Hupo Honigl 2 years ago. Top drivers dont use them in offroad.

On ISTC scale racing the wheels are smaller, so you want to long maintance intervalls so they choose the silicium nitrid (ceramic)

Hope I helped a lot.

[mattybucks]

This top driver uses them

http://www.trfracing.co.uk/page_1265187551237.html

Originally Posted by buhade

The wheels in offroad are bigger - so more torque on acceleration is on wheel.

The tungsten nitrid ones are more cutting the diff rings and so its more grippy - that i was told from Hupo Honigl 2 years ago. Top drivers dont use them in offroad.

On ISTC scale racing the wheels are smaller, so you want to long maintance intervalls so they choose the silicium nitrid (ceramic)

Hope I helped a lot.

[Toyman]

Can anybody comment on this:
While holding the spur gear, spin one rear wheel. The wheels should continue to spin when you let go for about 1 second.

Is this the case for AE diff? When I do the exercise with AE stock diff at stock setting (undo 1/8 turn) the wheels do not spin for 1 sec, they stop almost immediately.
Is this correct or should I loosen the diff a bit?

[peetbee]

Never heard that before, if your diff is loose enough for the wheel to spin (whilst holding the spur) then the car surely won't be going anywhere under it's own power!

[smokes]

Read this page first this will give you super smooth diffs.

http://www.teamirsrc.com/techtips.html

And if you resand the rings each rebuild the better the diff will get!
And the diffs stay smoother for longer.

[Adam F]

Originally Posted by Toyman

Can anybody comment on this:
While holding the spur gear, spin one rear wheel. The wheels should continue to spin when you let go for about 1 second.

Is this the case for AE diff? When I do the exercise with AE stock diff at stock setting (undo 1/8 turn) the wheels do not spin for 1 sec, they stop almost immediately.
Is this correct or should I loosen the diff a bit?

Are you sure this is referring to ball diffs and not geared diff's?

[RC944]

Originally Posted by smokes

Read this page first this will give you super smooth diffs.

http://www.teamirsrc.com/techtips.html

And if you resand the rings each rebuild the better the diff will get!
And the diffs stay smoother for longer.

is this not the complete opposite of received wisdom on finish of diff rings? im confused

[Toyman]

Originally Posted by x313

Are you sure this is referring to ball diffs and not geared diff's?

The quote is from Tamiya link above. The "advice" is for ball diffs for sure