K1 Diff build question
 

Hi all,

Just bought a K1 today from Steve Webbs Models in Frodsham. I was building the kit and have come across a slight problem. I built both diffs together and one of them is silky smooth and the other is really notchy!

Anyone have any idea what might of caused it. I am worried that the biff balls are faulty straight out of the packet?!

Has this happened before to anyone?

You'll get this feeling if the diff gear is the wrong way round. Take it apart and ensure that the gear is in the correct orientation in relation to the male outdrive. The lip on the gear fits into a groove on the male outdrive.

Hi,

I have tried splitting it all down and cleaning it then rebuilding (many times) to have the exact same result.

Sand the rings and see if it helps....A 600 or 800 grit paper will do.

So, let me get this straight. You want me to sand my ring? :o

have a look at this,

http://www.youtube.com/watch?v=bv3AC-Jjhbk

Hi,

Yeh already watched this. Done exactly what he did including the Schumacher bearing blaster (racers best friend). I will have to give the sand paper idea a go!

Did you run it this way? sometimes my SV2 Diff feels notchy, after a quick run, or a few acceleration in the living room it's gone and it runs super smooth.

I have spun it up on the bench. I tried holding one wheel to engage the diff but it its still very notchey!

Adrian,

When you say 'notchy', can you feel every ball as it were, or is it just quite rough? Is the notch very pronounced each time? Does it occur at a consistent frequency?

Initially it was very frequent. After slackening it off a touch and running it on the bench it is not as noticeable but still feels very gritty. the front diff is as smooth as butter though, it just feels COMPLETELY different to the rear as if the rear diff has been run for a year.

Hi Adrian
If your still having problems call in the shop and ill take a look at it for you.
Mat

Use ceramic balls. They are more consistent with less imperfections so more chance of getting it right first time. Over tighten steel balls and flat spots will ruin the diff action. Ceramics don't flat spot

Regards

Buds

The kit comes with ceramic balls.

Ceramics are smoother agreed. But they're also more brittle and slip more easily than carbide.

Hi Matt,

I would but it will not be until next Saturday again due to work.

no problem Adrian see you then

Well I stripped it down completely and cleaned it all using bearing blaster. I used 600 grit sand paper on the metal plates with a little machine oil then re-built the entire thing back up again.

Guess what, still not smooth at all. It is just the same as it was before. The only thing I can guess that is wrong is that one of the diff balls in knackered with a manufacturing fault as its done this from day one of the cars build and it has never been run.

Sad times!

Its lucky I have a very good model shop where I bought it from who can take a look! Matt and Robin this means you guys :-)