- Serpent S411 - James Reilly - Tricks regarding differential, shocks o-rings & suspension blocks -
All the kits come with the 2.25 chassis and the 2mm top deck now. The chassis is easy to identify it doesn't have the cut outs on the outside for a lipo with tabs.
The gear diff is not as smooth or as "free" out of the box as some of the others are. I suspect that in its original use, the 733, a little notchyness goes away very quickly with the prolonged run time of gas qualifiers and mains.
However I have figured out a couple tricks to free up the diff quicker.
1. Assembly the diff without orings put some very fine lapping compound (found at automotive stores for valve lapping) inside this will remove any of the high spots on the gears. If you have a worn out dogbone you can make a little drive for a drill OR if you have a drill press you can lightly clamp one out drive in the chuck and hold the case to run the gears in. Be careful, you need your fingers. Run until smooth. Clean out very well.
* Do not get any lapping compound on the out drive shaft.
2. The X-ring is a little tight again in the gas car I think that is best. In electric I think it is a little too much drag as the X-ring has double the friction surfaces. I trimmed and of the legs of the X down to decrease the compression on the X-ring. This felt much better, time will tell if it leaks sooner but I'm also looking for a O-ring to try as well. One of my teammates gets his car next week, when we build his car I'll take some pictures and show you guys.
That all equals a really smooth diff very quickly without waiting for it to break-in.
Suspension Blocks, I really like to know the actual width of the blocks so I measured the center to centers so I'll share that too.
0 = 41mm
1 = 42.5mm
1.5 = 43.25mm
2 = 44mm
2.5 = 44.75mm
3 = 45.5mm
3.5 = 46.25mm