problem with 8297-B MOD

[Lauris]

Hello!

I am currently working on heavy MOD of 8297, I have sucessfully changed the front part of the model including a gearbox run by M motor, so the model has motorized winch and second output (probably for door lift), as well as servo for steering.

I didn't had problem with adding XL for propulsion. I am keeping the original suspension of 8297-B and RWD layout because I am too lazy to invent my own :D

The XL propulsion output goes to 20T-reduced to 12T, then again 12T and back to 20T and then standard 3L diff. I think it's enough reduction for XL...

But now I have noticed a glitch... when standing without pressure on suspension, the yellow shock absorbers push to the steering arm (part 57515) so much, that it generates too much friction between steering arm and CV joint (part 32494), making one wheel turn slower and sometimes almost stop. This happens also when I pick it up in the air - one wheel turns (the one in the "gear" side of differential). If i slow down the fast spinning wheel, then the other that was slow, start to spin faster as if there was no problem. Also, if I apply pressure to shock absorber, so the CV joint and universal joint go straight to the differential (instead of being in angle), the friction is less and speed of both wheels becomes somewhat similar. Here's two pics of rear suspension from underside, that might help to undersand: http://www.brickshel.../dsc_2139-2.jpg and http://www.brickshel...-B/dsc_2137.jpg

As I thought that this is due to the pressure shock absorber is creating towards the steering arm, I lifted the shock absorber one stud higher, so the angle is wider and accordingly, lower pressure (ofc, it made the chassis flat instead of the lifted rear as with 8297 B). But the problem still exist.

With current setup I noticed, that when driving or checking wheelspin while they are lifted in air, they turn fine when "driving" backwards, but loose sinergy and start driving with gear crack sound, when "driving" forward.

So the question is - can this be "cured" keeping the 8297 rear suspension setup, maybe by replacing a part (differential?) that might be faulty? Or this is going to happen anyways (some natural situation with XL)?

I had the nasty sound of slipping gear crack with my previous MOD - 9395, but in the end, I managed to make a drivetrain, that doesn't crack (http://www.brickshel...V2/dsc_0487.jpg) .

Now I hope to get an advice, as I don't have experience with XL motors, as well as suspended axles, and maybe I am doing something totally wrong...

thanks!

Lauris

[zux]

I have discovered similar issue some time ago. My suggestion would be to use 42000 wheel hubs with liftarms of required length.