Changing diff fluids and had a couple questions... (1 Viewer)

[Malleus]

IMHO, it depends on the size of your wallet. There's nothing wrong with using non-synthetic gear oil and, there's a good case to be made that, under normal driving conditions, it's a waste of money.

The only reason to "flush" the gearcase with oil is to remove any contaminants that haven't settled to the bottom of the case or stuck on the magnet. If you follow a regular maintenance schedule and change when you get the diffs wet (I mean under water, not driving in the rain), you'll be fine.

 

[Malleus]

I wish I knew more about synthetic vs dino - there are some real experts out there that swear by certain fluids. What I can say is that having switched to synthetic in my 100, 1st Gen Tundra, Tacoma, and FJ Cruiser, I noticed no difference in performance or debris at changes but my wallet is lighter.

I did notice this year that I was hearing a light whine from my t-case on cold mornings (under 10*) and switched to synthetic in it. The whine was still there but seemed to go away a bit quicker with the synthetic. While the motor, trans, etc. all get to heat up as the vehicle idles in the driveway, the diffs and transfer case don't warm up as much so I just take it easy for a bit. It's probably just a function of having put quieter (newer) set of tires on it and actually hearing the whine.

The synthetic stuff is stickier, that's why your whine disappears faster.

 

[AlpineAccess]

The synthetic stuff is stickier, that's why your whine disappears faster.

My neighbor (chemist) was explaining that most synthetics have a much lower pour point and don't have waxes that cause it to thicken as much - at the end of the day I don't know/care as it seems to work to quiet the gear lash quicker.

 

[Hokie99]

Interestingly enough, Blackstone Labs, says that after thousands of oil analyses they do not see any difference in wear metals after continued use between conventional vs synthetic.

I ran 10k miles on conventional in my Tundra and then 10k on synthetic and had both analyzed and no difference at all on wear metals. I was pretty shocked.

I am sure in extreme circumstances where tremendous heat is introduced that would change things, but for most of us I am guessing it doesn’t really matter.

Just my 10 cents.