Dagr

iTrader: (4)

Ok, so I've seen many threads recommending various setups for various vehicles, etc, etc... which makes perfect sense in terms of performance adjustments.

For a more basic question which I have been wondering... how often do you need to replace the oils in the shocks/diffs as a normal basher/sometimes racer? How can you tell when its in need of a rebuild?

Since coming back to the hobby its one of the areas of my vehicle that I just haven't really ventured into yet...

Thanks in advance!

GizmoJunkie

iTrader: (5)

I rebuild shocks as they leak.

Every few heavy race days, i flush old shock oil with new. Basically flushing out the dirt that has gotten pulled in there. It makes rebuilds last a lot longer.

Or i will change the weight of the oil which takes care of the flush

As far as diff oils, i can see that lasting much much longer. Those gear diffs are pretty tough.

KingdomRacer

iTrader: (5)

This tends not to be true at all.
Shocks tend to need way less rebuilds as compared to diffs.
Diffs should be rebuilt every 3-4 race days and others will even recommend less than that.
I found that diff case size also determined when it needs a rebuild.
In my experience larger diff cases held their consistency longer than their smaller counterparts.

Rufus2010

iTrader: (3)

Kingdo--, are you talking about ball diffs, gear diffs, or all diffs? I believe the thread is about gear diffs.

Dagr

iTrader: (4)

Yes, I meant gear diffs, thanks.

Super Coupe

iTrader: (1)

Why would you need to change the fluid in a gear diff that often?

Dirt-Doggy

i ran 20k in my dif. man that truck was hooked

BuggyKing

iTrader: (17)

I rebuilt my shocks everyweek and diffs every 2 weeks. I ran my car quite a bit so I like to keep up on the maintainence for performance reasons.

KingdomRacer

iTrader: (5)

I was talking about gear diffs and personally have never had to rebuild my shocks more than my diffs.
On second thought, I will change oil in my shocks due to temperature but not because it needs a rebuild.

racer1812

iTrader: (31)

What exactly do you need to "rebuild" in a gear diff.? If it doesn't leak what's the issue? The fluids not going to "wear out"

KingdomRacer

iTrader: (5)

Really not so, the oil gets gummy and inconsistent and does in this sense "wears out"

Here is a paragraph from an article explaining diff tuning.

OIL CHANGE
Fluids wear out. Even though you really cannot judge the effectiveness of any oil by the color, it is a good indicator that it's time for a change. Chad usually changes his diff oil every three to four club races, and rebuilds his diffs before any major event, and if he's comfortable with the setup he generally doesn't change it. Regular rebuilds are a cheap way to make sure the differentials stay consistent.

And here's the rest of the article:
http://www.rc411.com/pages/howto.php?howto=24

KingdomRacer

iTrader: (5)

Another thing I forgot to mention is that shock oil tends to retain it's consistency way longer than diff oil (because it's light silicon oil) and there really shouldn't be a reason except for temperature and chasing a setup that you should have to rebuild or change oil in your shocks more than your diffs.

GizmoJunkie

iTrader: (5)

+1 This isnt engine oil.

Fluid does wear out, Ill give you that. It collects particles of metals wearing and such also, this is the bigger kicker. I can see a diff fluid change shortly after building to remove small shavings and particles after a good break in.

Beyond that, i can only see changing it to change your setup, just like shocks.

Diff oil is really similar to shock oil, it is all silicone. It doesnt break down so easy, and its not like it comes into contact with 450-500+ deg moving parts.

I rebuild a ball diff about every 6-8 race days, i certainly would not recommend a similar maintenance interval for a gear diff...