Icon Shocks - What Am I Doing Wrong? (NOT another leak thread)

[ajsmcs]

After a year of waffling back and forth, I finally made the leap and bought myself a shiny new SCX10 (II) builders kit. I'm currently about halfway through the build, but I'm having trouble with the Icon shocks.

Mind you, this is NOT the first time I've ever built/re-built shocks. I've done the ones on my Traxxas Rustler and T-Maxx many times.

I built them exactly per the instructions. I lubricated the o-rings (I used Labelle 106 that I had on hand for my model trains. Apparently its designed for this purpose) I made sure they were the specified length with my caliper.

3 out of 4 slide nicely down their shaft. One of them sticks badly, despite the lubricant.

That is not my biggest problem, though. I filled the body with oil up the the top edge - per the instructions - worked the shaft up and down (teehee...) to release bubbles, let it sit a few minutes, and installed the cap.

But when I go to compress it all the way, it gives a LOT of resistance before eventually blowing the cap off. Additionally, it looks like the plunger/damper extends past the top edge of the cap when fully compressed. Meaning that there would be no way to fully compress it with the cap installed. Does that seem right?

What am I doing wrong here?

Any help is gladly appreciated. Thanks!

 

[badhoopty]

by sticks do you meant it feels notchy or is just stops and cant be compressed any further?

will the shock compress all the way w/o fluid? sounds to me like you may need to check the shock body, piston, and shaft for any ridges or burrs for the notchy thing and use a little less fluid for the locking and popping thing.

 

[QuesoDelDiablo]

RE: the binding:
Is it binding because of the shaft or the piston, can you tell? I had to lightly sand one of my pistons to get it to move freely, that or you clean out the inside of the shock with a flapper wheel and some 600grit. If it's the shaft, try chucking it in a drill and polishing it with some emery cloth.

RE: the compression:
When you put the cap on, have the piston at the very top of the shock in a fully compressed state. This may result in a little negative rebound, to adjust it just play with the pistons position when tightening the cap. (this allows room for the oil to displace and allow the shaft to enter the shock body without resistance)

 

[ajsmcs]

OK, Update
1) The Compression - I think I misinterpreted the instructions. I filled it to the top, worked the piston, wiped the shock body, and then topped it back off. I just assumed the last part, but it turns out that was what was biting me in the butt. When I tried it again without topping it back off, it worked fine.

What distance do you guys prefer them to rebound after compression?

2) Binding - At this point I'm pretty sure its either the piston or the shock body. I slid the o rings out so that they wouldn't restrict anything, and the piston still hung out.

In related news, I need two new o-rings. X_X

Thanks for your input!

 

[LSXGMC]

Sounds like too much oil in the shock, which causes them to hydrolock. Fill it up and leave about 1/16 inch from the top. Work the shock shaft up and down to release bubbles, ensuring that the piston isn't pushed past the top of the oil (it will "grab" air and pull it into the oil if you do this). Once you're satisfied the air bubbles are out, start to thread on the shock cap (should have the rod end on it already, as well as the bump stop if you are using one). Compress the shock shaft completely, and oil should start leaking between the cap threads. Fully tighten the shock cap with the shaft fully compressed. You should have about 1/8 inch rebound after its all assembled.

Sent from my mobile device

 

[allanon1965]

as said earlier, sand the piston edges down slightly, you have a burr or rough edge..happened to mine...once sanded it works like butter.

 

[XSRCdesign]

It's the piston, one of the 4 were too large on mine. Same exact thing on my buddies also

 

[ajsmcs]

Sounds like too much oil in the shock, which causes them to hydrolock. Fill it up and leave about 1/16 inch from the top. Work the shock shaft up and down to release bubbles, ensuring that the piston isn't pushed past the top of the oil (it will "grab" air and pull it into the oil if you do this). Once you're satisfied the air bubbles are out, start to thread on the shock cap (should have the rod end on it already, as well as the bump stop if you are using one). Compress the shock shaft completely, and oil should start leaking between the cap threads. Fully tighten the shock cap with the shaft fully compressed. You should have about 1/8 inch rebound after its all assembled.

Sent from my mobile device

This is one of the most helpful answers to any question I've ever asked on a forum. THANK YOU.

 

[1967Typhoon]

I had to sand all 4 pistons down on my kit and they still stick all the time. I was not pleased. The machined pistons are going in soon.

 

[JayGreig]

Yeah, same issues with the shock bodies being just a little on the rough side. Mine were binding at full droop, so I cut up a felt polishing wheel, locked it into a cut off wheel spindle, then chucked it in my drill. Little metal polishing compound followed by some Mother's aluminum polish and they're like butter. I also opted to go with a little heavier silicone than what came in the kit to minimize the bounce...40wt Lucas silicone.

 

[jeepgeek2002]

i filled mine up 60% so when you push the piston up .. the oil doesnt flow off..
Those instructions suck..

 

[ajsmcs]

It's probably uneven clearcoat inside the body thats causing it to bind. I ended up sanding down the piston enough that it works fine, but IMO it's definitely a much better idea to smooth out the body and leave the pistol alone.