KC ball diff loosening
 

Has anyone experienced their ball diff loosening? It did it with me straight out of the box. I've removed it and rebuilt it but the same thing happened! Any ideas or advice would be appreciated.

have you bed it in...as they need tightening after first few runs

Ah no, think I missed that step. Thanks for the reply.

I allways set mine too tight from a rebuild and they readjust, you are locking the grub screw onto the bolt after rebuild?

I'm sure I did lock it in after the rebuild. I think I'm going to rebuild it again just to make sure that's done, then I'll run it in and check it again.

I've personally not had any issues and that's even without fully running it in.

Just make sure the locking grub screw is in place.

Its not the same diff but this video explains how to build Schumacher Ball diffs pretty well.



What I have found that in the area when you are tightening a few turns at a time, I use my Bosch iXO cordless screwdriver to bed the balls in with a about 10-15 seconds each time, then when the diff is fully tight with all springs compressed, then back off 1/4 of a turn (it says 1/8th in the video anywhere between will suffice) and then put a cone point grub screw in the other side.

Then when the grub screw is up against the end of the diff screw, against it but not very tight at this point, tighten the main screw down onto it, I normally use a spanner in the slots of the outrider to hold the other side.

Other tips include making sure that you have the Small Race Washer in the end of the thrust assembly correct, if you have the large one in the wrong place it will bind against the outrider causing the diff to come undone, I have seen this when rebuilding other diffs.

Some people have been tempted to put thread lock on the screw, I personally wouldn't do this, the locking of the main screw with the cone point grub screw is sufficient enough.

My KD Diff initially I made some mistakes, however I have rebuilt many diffs, now and confidently say that they do not come undone and perform well, and ultimately are the same each time.

Hope this helps :thumbsup:

the ball diff in the KD has been a nightmare for me and many drivers I race with.

It doesn't help that the diff plates are made of what appears to be a very soft steel. If someone could recommend an oil for the gear diff which matches the consistency of the ball diff, that would be great!

It wouldn't be so bad if Schumacher had engineered the gearbox casings to open at the rear, allowing access without dismantling half the car....

From what I understand there are some harder plates in the pipeline, after a few runs, the current ones wear quite significantly, and do go "scratchy"

I don't know if it works as well with the KC, but if you take 2 of the gears out of the diff, it will act similar to a Ball Diff :thumbsup:

I can get a KD ball diff feel from a gear diff by removing all the gears!

what oil do you run when you remove the gears - or does this not matter and just run it empty?

I haven't run without gears, I generally use a ball diff, however, I think you just use the oil that you would normally use.