 The problem with open transmission cars like the 501X, Yokomo BX and all their forerunners is that dust and debris can, and does, enter the drive train - requiring more maintenance and attention than more 'sealed' designs. There is little that can be done to stop dust getting around the belts and differentials. Indeed, the rear of the 501X is open to allow dirt to exit at the rear. In all my running I've yet to have a problem with dirt, water or debris damaging anything. Dirt and fine dust will get into the diff no matter what you do however, especially at the rear. And this is the weak point. |
 |
 |
Nice! the 501X differentials are exposed to dirt which rapidly builds up and coats everything. |
 When it came to cleaning my 501X for the first time since I got it (second hand), I'd already run it at a few meetings, so I knew it wouldn't be pretty. The differentials had been fitted with KANZEN ceramic balls, and were actually very smooth indeed still, but with the diff's out of the car it was clearly not very pretty. The whole side and all around the balls was covered in dirt - yuck.
To cut down on maintenence various companies sell these vinyl stickers, pre-cut to fit around the diff pulley and better seal things up to give a longer life between maintenance. |
I didn't want to go out and buy some over priced tat and it didn't exactly look hard to do. So I fired up Adobe Illustrator and measured the diff I'd just rebuilt.
With the outside diameter of the pulley measured with my digital calipers, I 'guessed' at a good internal diameter which would, hopefully, cover enough of the diff so as to provide a good seal. |
  |
 |
Hmm, not bad - the 'first pass' diff covers still had a small gap to allow dust to enter. I ran the diff for a fully race meeting which included some severe rain. On closer inspection it was clearly better than it would have been without a cover, but not perfect since there was still a small gap that allowed dust in.
The problem of having a smaller inner diameter is of course that the vinyl cover can stick to the diff half and cause havoc. To solve this and better seal up the diff, I made the inner diameter a couple of mm smaller but put a thin layer of silicone grease on the side of the diff half where the vinyl would end up touching.
 Making sure the pulley is perfectly clean and dry (so the vinyl would stick well), and with the diff half coated in grease - the eventual seal is near perfect. |
|
Here are the install steps of fitting the final diff covers. The grease is important otherwise the vinyl covers will completely lock up the diff.
|
 |
This was much better. With the greased diff halves, the vinyl didn't stick - but I was a little scared that the grease might 'dry up' and eventually cause some failure. I gave the diff a couple of meetings in the rear of the car and despire having plenty of dirt around the outside and stuck to the think layer of grease - there was no dirt or grime inside the diff what so ever. Result.
Left: This is the diff after one meeting - the seal is pretty much perfect here.
Making your own dirt shields with a knife and some vinyl / a sticker sheet you don't need, shouldn't be too hard, though probably not quite as neat as using a plotter like I've done. If you'd like some of these then get in touch with Mrs.oOple and ask her for details. :)
|
|
