Going to Service the Transfer case soon. Probably going to use Redline.

[sag2]

ATF 4 is a licensed product and should be the same from any source if they have it packaged as ATF+4. It is already synthetic.

 

[NIsaacs]

that sure is correct from dealers sight, but if you check out the others like Ford & Gm that used the same TC, one calls for Mercon something and the other wants to see Dexron VI in the same TC.
See the point?

Exactly, I agree they all use the same t-case and spec their own fluid, mostly ATF. Since there is interest in using what is best for the t-case and not what is best for the manufacture, I decided to do some research. This is just for fun and not a recommendation on anything. It may or may not apply for you.

ATF has an additive in it to make it less slippery, to grab and hold automatic clutches. Same thing for motorcycles/ATV clutches, they spec the engine oil accordingly. No oil with the "fuel savings" logo, too slippery. With this in mind, "maybe" manual transmissions and t-cases spec ATF for the syncros. Same with Syncromesh type oils, it helps the inexperience drivers shift a manual transmission. I noticed this when I went from my factory fill on my NV5600 to 15/40 engine oil. The shifts are slower which is the way I shift anyway, so I don't need or want the syncromesh.

Ford and GM might have a better oil for the t-case, than ATF+4. They both (now) use oil "not for use in automatic transmissions" hummm……

Ford:https://torqueking.com/product/737/1-quart-ford-motorcraft-xl-12-transfer-case-fluid/

GM:https://torqueking.com/product/794/...ual-transmission-transfer-case-fluid-1-quart/

 

[DaveHess]

I listened to Cerb about two years ago and switched from ATF+4 to Pennzoil Synchromesh in my T-Case. Not a single issue and I sleep better at night!

 

[nibroc]

ATF 4 is a licensed product and should be the same from any source if they have it packaged as ATF+4. It is already synthetic.

worth noting

 

[cerberusiam]

ATF+4 is not a true synthetic, which is really secondary to the discussion which is the t-case and lubrication efficacy. There are a lot of builders that will tell you it doesn't make a very good lube for even the automatic transmissions it is used in. No one running hot and heavy and using these trucks to the limit is very impressed with ATF+4 in the manual trans or the t-case, that is just the way it is.

 

[KATOOM]

ATF+4 is a group III hydrocracked synthetic. Yes...most synthetic lubricants you buy over the counter are of a petroleum base too.

Really I find humor in the semantics too because all oils are synthetic if you want to consider the fact that its all synthesized by man after being mined from the Earth.

 

[cerberusiam]

It all depends on the group they belong to and that is determined by their content. PAO's which compromise group IV and V are synthetics, group III have a highly refined base with synthetic additives.

There is a marked difference in the meaning of synthetic and synthesize., No semantics can change that, only incorrect usage in content.

Group II and III oils are refined not synthesized, there is a marked difference there also. Claiming a group II engine oil is synthesized is factually wrong, it is refined petroleum period. Claiming a group III base stock is synthesized is technically incorrect also. It is simply refined beyond what can occur in nature, and then the marketing fights began.

 

[RVTRKN]

TDR Member "CKelly1" switched his CTD fleet transfer cases over to Synthetic 50wt Trans fluid a couple of years ago, after tearing down a failed transfer case and rebuilt it using that oil. He now has his fleet now running synthetic 50wt Trans fluid last I heard. Even though its a bit to early to tell, I switched over to Mobil1 synthetic 50wt Trans fluid in my transfer case and it seems to be just fine. BTW that is the same oil in my G56, that has over 30K plus miles on it now. I guess its time to change that oil.

 

[Northfork]

Well now I am glad I posted this, looks like it was of value to others as well.
I have an extra gallon of the 50wt. Mobil 1 trans fluid I bought when I serviced the G56, I will pick up a quart of the Pennzoil Synchro this week, mix up a couple of quarts, and change it out soon. Thanks for the tips guys.
Sometime this winter when we get a break in the weather I will do the front and rear axles. Sorta watching the Gale Banks you tube series on diff covers right now. I am considering an aftermarket cover for the rear but want to see where this goes before deciding.
It is an interesting series for sure.

 

[dsldude]

I have been running 50wt in my t case for about 6000 miles now. It slowed the leak down at the front trans to t case seal to almost nothing. Runs a bit quieter now too. Im sold on this. A t case is just a gear box really. I would never run ATF in any gear box so why this? No clutches. ATF is a great cleaner and is mildly abrasive. Maybe this is why all auto transmission's have such short life spans.