Royal Purple Synchromax in Transfer Case

Does anyone have any experience using Royal Purple Synchromax fluid in their transfer case? I recently went through a mud pit in Apple Valley, CA and got stuck in that mucky stuff well above the front and rear axles for near an hour. I drained the fluid on the rear diff and transfer case and both fluids looked surprisingly clean. I decided to drain and replace any ways just to be safe. I used

$30 Mobil 1 75w-90 Synthetic Gear Lube - 1 Quart (Pack of 2)

Mobil 1 75w-90 for the rear and Royal Purple Synchromax on the transfer case. Maybe I'm just imagining things but I took my tacoma onto a dirt road it seems like my transfer case is engaging smoother, quieter, and slightly quicker than ever before. I know its not miracle oil. Only had 23k miles and never exposed to mud or water in the past. I do light off roading and engage 4wd about every other month.

The company's website says its compatible with transfer cases and a few members have said they used it in the past but does anybody have any opinions as to why or why not I should continue using? I used the search bar but not much really came up. So far I only have about 400 miles on the Synchromax.

 

Eh...

It may be compatible with *some* transfer cases, I know some GM use auto trans fluid in their transfer cases, however auto fluid is thinner typically mineral oil based and doesn't have the same shear or compression properties or film strength.

Your transfer case probably is engaging smoother as auto trans fluid does have a crap ton more detergents and friction modifiers so the fluid itself is actually slicker (has more lubricity) it may have cleaned some accumulated junk from being neglected prior also but at the cost of not protecting your internals as well.

You should run a high quality GL IV (GL V is okay) in your transfer case such as Redline MT90 (what I use) or Amsoil

$30 75w-90 Synthetic Gear Lube - 1 Quart (Pack of 2)

75w-90 or similar. (Mobil, Royal Purple etc.)

 

Thanks for replying. Should I be replacing this immediately or is it fine to leave for the time being and change out in a few thousand miles?

 

3rd gens call for some ridiculously expensive toyota LF75 wt fluid. Only thing compatible is some Ravonol stuff that is from Europe. I wouldn't stray to far from those.

 

I imagine you're fine especially if you're not using 4wd much, however being a nice shiny new 3rd gen you may want to use stock fluids to not void any potential warranty.

Also transfer case fluid should be good for like 40k miles before needing serviced. (Drained and filled with new fluid.)

It was probably a good idea to do a drain and fill especially since brand new gearboxes do produce quite a bit of metal particulate as things wear into each other during break in but again I wouldn't worry too much about it.

 

Redline makes a transfer case oil that is compatible. I've been in contact with their company and it is equivalent to the expensive Toyota oil. You can get it for around $20-$25.

Red Line Synthetic Oil. MT-LV 70W/75W GL-4 Gear Oil (redlineoil.com)

 

Engineers determine the lubricant specifications, trust the engineers.

Often it seems lubricant specifications bring up a conspiracy theory -- "...Toyota calls for a special oil so they can make huge dollars..." -- This really doesn't make much sense.

If you think about how often transfer cases get serviced in the real world (outside of enthusiast circles) Toyota (or any other manufacturer) would make a lot more money by just adding 1$ to the cost of every set of brake pads.

NOTE: Any (brand) lubricant that meets the specifications is acceptable, in the case of the 3ed gen transfer cases there seem to be very few products available other than Toyota OEM.

 

You don’t need to change diff and trans oil that often.

 

I know it's a bit soon change the fluids at only 23k but having been submerged in mud for almost an hour I just wanted to play it safe incase there was any mud or water in the housings. I extended the breather tubes and they seemed to have done their job well but. I have heard that some people have still taken in water.

So what's everyone's take - should I just leave the Royal Purple Synchromax for a while or should I change out for a more appropriate gear oil ASAP? I appreciate everyone's input on the matter and will take it all under serious consideration.

 

Key-Rei already said he thinks I should be fine for the time being, but unless anyone else thinks otherwise I might leave it for a short while.

 

Personally I'd change it but it's your truck

 

I would change it. The transfer case chains are still turning in 2HI, you don't want anything wearing prematurely.

 

You asked:
Engineers determine the lubricant specifications, the Synchromax is not on that list, I would change it out.

 

Nearly the same for the ATF these automatics use. Been told one needs to be careful about adding another brand ATF even if it claims it meets the manufactures specs., it still may not be be totally compatible with whats already in there, causing issues down the road.

 

What I was ment to get across was that, you probably haven't done any damage to it yet, but I would still change it out at your earliest convenience to be on the safe side.

Any lube is better than no lube but the right lube is the best lube.

 

Agree - change it out to approved OEM fluid.

 

I ran syncromax for a bit, the shifts definitely seemed slower and sluggish, after some talks on here I decided to switch it out for ravenol. That was many many miles ago. No issues now

 

Modern vehicles are built to much tighter tolerances and with different materials than in 1970 for example, the specific lubricant specifications reflect that.

Some folks seem to have a difficult time accepting that what they always used or what their dad, neighbor, the guy at the store, even a mechanic said isn't right if it goes against what the engineers said to use.

Chrysler introduced the Ultradrive transmission in the late 80's, it required a special fluid as noted in the owners manual, service manual and on the dipstick. Many failed because the popular reasoning of the day was "we always use Dexron in Chrysler".

 

Thanks for all the input guys. Based off the overall consensus I think I'll be switching out the Synchromax for OEM or something close to OEM spec. Probably this week or next, before that long drive from Socal to Vegas.

It was free fluid given to me by a friend and it was interesting to see the difference in how the transfer case acted. Seemed like things ran slightly smoother and quieter in regards to engaging 4wd, but I know some people said they felt otherwise.

 

I purchased mine from OEM Parts Source, just under $60/quart, best price I found.
Transfer Gear Oil LF 75W - Toyota (

$91 08885-81080 TOYOTA Genuine Transfer Case Gear Oil LF 75W 1 Litre 08885-81080

08885-81080)