Sticking shocks help

[theone13]

I know, another thread about shocks, but I need some help here. I have a Marlin and ever since I got it out of the box, the shocks have resisted compression at first but then move freely, until it's left to sit for a minute or two, then they're back to sticking. I've taken them apart, removed the internal springs, added a little oil just for lubrication, and everything else looked ok, so do you all have any ideas on how to remedy this?

[teamreedracing]

Check the orings at the bottom of the shocks where the shaft comes out

[theone13]

Originally Posted by teamreedracing

Check the orings at the bottom of the shocks where the shaft comes out

Check em for what? I've taken two of them apart and they looked fine. I think I have some o rings from other shocks I could try switching in.

[teamreedracing]

Sometimes when you tighten the bottom to tight it squeezes the orings to tight and the shaft sticks

[theone13]

Yeah, I'd messed around with not tightening the bottom all the way, and did notice it improve from that. I didn't want to leave them that way because, idk just seems wrong, but if that's what it's gonna take.

[58_Willys]

Since these shocks are not oil filled, you could remove one of the O-rings to free up the shaft a little. Also, an old trick from the off-road racing days, is to polish the shafts by putting them in a drill with some ultra fine sandpaper.

[HumboldtEF]

I recall RC4WD shafts are coated with something so sanding them down would remove this and they may oxidize or have unwanted effects.

Green slime is something I use to lube up the O-rings in my shocks https://www.rpphobby.com/product_p/asc1105.htm

Another trick to free up the O-rings is to get a slightly thinner spacer. Typically shocks will have an O-ring, a spacer and then another O-ring. The job of this spacer is to add some "crush" to the O-rings once the bottom cap is screwed on. In some cases this spacer crushes too much making the shaft feel sticky as it moves which is why not fully screwing on the bottom cap helps. The idea of swapping in a thinner spacer is to get less crush. Since you arent using oil in this type of shock if the O-ring ends up loose it wont matter because it doesn't need to hold oil (otherwise it would likely leak).

[theone13]

Thanks for all the tips guys, since the shocks aren't really functioning as normal shocks I at least want them to not hinder performance at all. I've unscrewed the bottom one full rotation and lock threaded it to keep it at that point, so we'll see if that does the trick, if not I'll try a smaller spacer.

[Flud unlimited]

Mine is doing the same thing, I’m going to try the slime.

[theone13]

Originally Posted by Flud unlimited

Mine is doing the same thing, I’m going to try the slime.

Good luck, hope it works for you, it didn't have any affect on mine.

[theone13]

Alright, so I thought my "unscrewing the cartridge some fix" was gong to work, but sure enough they were still sticking more than I liked. So I took the suggestion of a smaller spacer between the two o rings. I took out the stock spacer and rubbed it around on some 400 grit sandpaper for a bit, maybe took off a 1/4 to a 1/3 of the original size. Put it all back together, and they might just be good. Time will tell though, but thanks for the ideas and help.

[Natedog]

Originally Posted by theone13

I have a Marlin and ever since I got it out of the box, the shocks have resisted compression at first but then move freely, until it's left to sit for a minute or two, then they're back to sticking. I've taken them apart, removed the internal springs, added a little oil just for lubrication, and everything else looked ok, so do you all have any ideas on how to remedy this?

Stiction like you described is normal in most RC shocks that I've ever had, once they get an up/down cycle, start driving and it's not a problem.

Originally Posted by HumboldtEF

I recall RC4WD shafts are coated with something so sanding them down would remove this and they may oxidize or have unwanted effects.

Green slime is something I use to lube up the O-rings in my shocks https://www.rpphobby.com/product_p/asc1105.htm

Another trick to free up the O-rings is to get a slightly thinner spacer. Typically shocks will have an O-ring, a spacer and then another O-ring. The job of this spacer is to add some "crush" to the O-rings once the bottom cap is screwed on. In some cases this spacer crushes too much making the shaft feel sticky as it moves which is why not fully screwing on the bottom cap helps. The idea of swapping in a thinner spacer is to get less crush. Since you arent using oil in this type of shock if the O-ring ends up loose it wont matter because it doesn't need to hold oil (otherwise it would likely leak).

X2

The Marlin shocks are coated with some very low quality chrome that usually peals off within first couple crawl sessions ime. The standard TF2 shocks are not coated with anything, just plain steel shafts. Disassembled mine, one of OG TF2 RTR shocks had an oversized o-ring that wouldnt' hold any oil, found some HPI Savage o-ring leftovers and used them instead. Green Slimed all shock seals and reassembled with 3000wt diff fluid, works great! Over time and a good bit of crawling they have seeped some oil, but not a lot. If they get bad, I'll rebuild with all new rings.

BTW, I did not use thinner o-ring spacers, but that is a valid trick in some cases.

[theone13]

Originally Posted by Natedog

Stiction like you described is normal in most RC shocks that I've ever had, once they get an up/down cycle, start driving and it's not a problem.



X2

The Marlin shocks are coated with some very low quality chrome that usually peals off within first couple crawl sessions ime. The standard TF2 shocks are not coated with anything, just plain steel shafts. Disassembled mine, one of OG TF2 RTR shocks had an oversized o-ring that wouldnt' hold any oil, found some HPI Savage o-ring leftovers and used them instead. Green Slimed all shock seals and reassembled with 3000wt diff fluid, works great! Over time and a good bit of crawling they have seeped some oil, but not a lot. If they get bad, I'll rebuild with all new rings.

BTW, I did not use thinner o-ring spacers, but that is a valid trick in some cases.

Yeah, I'm used to a little bit, especially if the truck's sat for a while, but this was so extreme and would affect the suspension while out crawling, so I needed to do something. That's interesting about the shock coating, I notice a definite color variation on the part of the shaft that actually passes through the cartridge on bottom. I've only done a quick backyard test since all this, but it worked much better, so hopefully next weekend I can actually take it out to a real spot and see how it does.

[theone13]

Got it out today for a couple hours and the difference was night and day. Very pleased with how it works now.