Shock oil

[Lukas666]

So I had to disassemble and shorten some shocks I ordered for a lunchbox. I had no shock oil but I did have some Penzoil 10w30 so that’s what I re assembled them with after shortening them with some of that black hose from the stock friction dampeners. Anyone use engine oil in they’re oil filled shocks? And if so for how long and have they still remained dry?.... about 3 weeks later I built a Tamiya buggy with oil shocks and never used even close to 1/2 the bottle they supply you with in the kit so now I do have some. Tamiya yellow is what I have and from reading that’s soft/light oil. Should I bother changing it now or is there any negative effects from using the 10/30?.... I can’t see it breaking down seals as engines are full of rubber seals. The shocks seem to work great, they were very stiff from shortening them but that was due to the heavy springs the shocks came with being compressed more. I’ve  since changed those out to much lighter ones and now they work great. I’d say they’re medium to light shocks now. I haven’t noticed any difference with the 30 weight oil I think it’s fine but would like to hear from others.

[Willsls1]

Well just going off what I've noticed, motor oil is way thiner viscosity than RC shock oil. I'm using 27.5 wt in my shocks and stuff is like molasses compared to 10/30 wt oil. But whatever works! 

[mike in pa]

I figured that maybe it was mineral oil for shocks.  

[87lc2]

You can use motor oil in shocks, many have done it with no issue.  It will break down the silicone seals a bit faster than a silicone shock oil due to the detergents added, but not so often that it would be a huge problem.  Using motor oil for racing would be better since they contain less detergents/additives.  I would still recommend just using silicone shock oil, it's cheap enough and won't damage the silicone seals.

[SupraChrgd82]

10w30 is relatively thin, and changes viscosity with temperature, hence the “10” and “30”.  That will result in inconsistent handling.  

Motor oil will also deteriorate any silicone or polymer components in the dampers.

It is advisable to disassemble the dampers and wash all of the components well, then reassemble with silicone damper oil.  As a general rule for stiff springs, a medium or heavy damper oil would be appropriate to prevent it from acting as a pogo stick.  Softer springs are often desirable to increase traction, and can be coupled with heavier oil for jumping.

If you have pistons with smaller or fewer holes, those can be substituted for heavy oil.

[Lukas666]

10 hours ago, SupraChrgd82 said:

10w30 is relatively thin, and changes viscosity with temperature, hence the “10” and “30”.  That will result in inconsistent handling.  

Motor oil will also deteriorate any silicone or polymer components in the dampers.

It is advisable to disassemble the dampers and wash all of the components well, then reassemble with silicone damper oil.  As a general rule for stiff springs, a medium or heavy damper oil would be appropriate to prevent it from acting as a pogo stick.  Softer springs are often desirable to increase traction, and can be coupled with heavier oil for jumping.

If you have pistons with smaller or fewer holes, those can be substituted for heavy oil.

I’ll change it out soon... dunno if I wanna use the Tamiya 400 that’s leftover from my hornet it is pretty light and to be honest didn’t feel like it did a badword of a lot. What’s a good medium wt to go with? I noticed my local shop doesn’t have any Tamiya silicone oil on hand so it won’t be Tamiya brand if I choose to go heavier.

[Lukas666]

11 hours ago, SupraChrgd82 said:

10w30 is relatively thin, and changes viscosity with temperature, hence the “10” and “30”.  That will result in inconsistent handling.  

Motor oil will also deteriorate any silicone or polymer components in the dampers.

It is advisable to disassemble the dampers and wash all of the components well, then reassemble with silicone damper oil.  As a general rule for stiff springs, a medium or heavy damper oil would be appropriate to prevent it from acting as a pogo stick.  Softer springs are often desirable to increase traction, and can be coupled with heavier oil for jumping.

If you have pistons with smaller or fewer holes, those can be substituted for heavy oil.

I’ll change it out soon... dunno if I wanna use the Tamiya 400 that’s leftover from my hornet it is pretty light and to be honest didn’t feel like it did a badword of a lot. What’s a good medium wt to go with? I noticed my local shop doesn’t have any Tamiya silicone oil on hand so it won’t be Tamiya brand if I choose to go heavier. My local shop has Team Losi oil anywhere from 20WT-100?

[87lc2]

Losi & Associated oils are good, that's what I primarily use in all of my vehicles.  If you're unsure of the weight, start out with 30 and go from there.  If you're not racing and don't need to fine tune your setup 30wt will be good for just about anything.

[Lukas666]

Ok so my next question is what wt is the Tamiya 400 then roughly? I read it’s not rated as per weight really. I found this tho so maybe that is a good starting point the Tamiya yellow.

[87lc2]

400cst Tamiya oil is very close to the 30wt equivalent.  Here is a chart that compares CST to WT:

[Lukas666]

I’ll just be driving it in dirt fields around here and camping not racing it but I’d still like it to handle the best it can with those oil shocks I upgraded it to.

[nel33]

1 hour ago, 87lc2 said:

400cst Tamiya oil is very close to the 30wt equivalent.  Here is a chart that compares CST to WT:

Thank you very much for posting this. i went with 40wt on my TT02D hopup aluminum shocks and wasnt sure where my Losi 40WT oil compared to Tamiya in more precise weights.

[Jonathon Gillham]

4 hours ago, Lukas666 said:

I’ll change it out soon... dunno if I wanna use the Tamiya 400 that’s leftover from my hornet it is pretty light and to be honest didn’t feel like it did a badword of a lot. What’s a good medium wt to go with? I noticed my local shop doesn’t have any Tamiya silicone oil on hand so it won’t be Tamiya brand if I choose to go heavier.

I went with TLR oils since they sell packs like this (they do another one which fills in the gaps so I have 17.5wt to 45wt in 2.5wt increments).

https://www.rchobbies.co.nz/team-losi-tlr74020-certified-silicone-shock-oil-6-pack-2oz-20-25-30-35-40-45wt/?gclid=Cj0KCQiA962BBhCzARIsAIpWEL0PJm2vuD61ls8oun-acOhUzgnnJgBlbaOwDOgI1YXURxRn_0peQ5kaAkmLEALw_wcB

While expensive its about half the cost of buying individual bottles and then you have a range.

Tamiya oil is measured in CST which is an actual measurement. Losi, Associated etc use their own measurements they refer to as Wt which is only useful to compare between their own range. Its best to buy a range from the same supplier as the gaps between the oils should be consistent, but when looking for setup sheets you'll need to find a conversion between brands as illustrated by the table above (400CST is 32.5 in TLR and 30 in Ae)

[Lukas666]

2 hours ago, nel33 said:

Thank you very much for posting this. i went with 40wt on my TT02D hopup aluminum shocks and wasnt sure where my Losi 40WT oil compared to Tamiya in more precise weights.

Just went to the hobby shop snd got this. Little heavier than what I got but nothing crazy. They had a Tamiya Bruiser there....$1000 holy crap. 

[nel33]

49 minutes ago, Lukas666 said:

Just went to the hobby shop snd got this. Little heavier than what I got but nothing crazy. They had a Tamiya Bruiser there....$1000 holy crap. 

500 CST/40WT was a tad bit heavier than i was expecting to see on the conversion charts but its not over kill on a  road drifter so im content on that. 35WT oil might be a future purchase but given winter and covid i havent had many places to take mine out for a run outside of underground parking areas... i have yet to see how it handles though once spring comes...

[Lukas666]

Well I did the front shocks.... way more resistance compressing the shock now compared to the 10w30 even just without the spring installed. I noticed the quantity of oil you add determines the stiffness too. I’d say I filled it about 90-95% full? Would that be correct?