Transfer Case Oil

[gnpenning]

Some good points about overlooked things for oil.

As a side note I like to run manufacturers recommend non detergent in my compressors, mower, etc. Our local tractor supply carries it as does Walmart. Walmart has it on the same side as oil filters. It's not with the rest of the oil selection.

 

[nvrstuk]

I just am getting better on what not to do!, with the help of everyone here!

Valvoline 50 wt works good. (Update: non detergent which I forgot to add earlier)

 

[ntsqd]

I long ago read that 50 wt non-detergent engine oil is the spec for the Dana 20 in Broncos. No idea what was spec'd for the Dana 20's in Jeeps etc.

If those thrust washers in the Bronco D20 have exactly the same Dana p/n as the the thrust washers in a Jeep or IH D20, then whatever is spec'd for them should be acceptable.

If the p/n is not the same, then I'd stick with the Ford recommendation. If that can't be found I'd talk to the tech folks at Redline or Amsoil or Royal Purple or Torco or Swepco (pick your poison) about what they would recommend instead.

 

[DirtDonk]

Can’t say this is any guarantee about the part number, but when I rebuilt my Dana 20 many years ago, I couldn’t find “Ford“ thrust washers. So I bought thrust washers for a “Jeep” Dana 20.
They were the same as the ones I took out.

Hmm, I wonder if the thrust washer is listed in one of my bearing books. One more thing to look up…

And for the record, my transfer case had always had 50 weight non-detergent motor oil in it, up to the point that I rebuilt it. Didn’t need a rebuild, but I had it out to work on the transmission. So what the heck…
This was at approximately 105,000 miles if I remember correctly.
From the rebuild on, I used a Redline 75w/90 synthetic. I chose this because I wanted one lube for the differentials, the transfer case, and the transmission.
At the time, I knew about the reasons for not using gear oil, but the Redline brand (at the time and for that specific type) said it was compatible with yellow metals.
Shifted like butter and did everything right and was quiet for all those years from 50,000 to 175,000.
Sold the transfer case to member 904Bronco here for a project.
Maybe he can add some info if he took it apart. I think he just installed it as-is, but maybe he put in some new gaskets and looked it over.

Either way, the key for me was that the bottle specifically said “safe for yellow metals“ or words to that effect.
The mechanicals worked beautifully for both 50 weight and synthetic gear lube.

 

[ep67bro]

Well this thread has me questioning everything!!!

Every bronco I have ever had had Gear oil of some kind in the t case. You could tell just by the smell of it! I could see using the 50 weight oil but like other have said not the easiest to find! When I took my Tcase out to fix the adaptor I think I put 75 90 W synthetic blend in it. My 67 has had gear oil in it since I got it 20 years ago and I know I used gear oil in the NP 205 that was in my 68 high boy and never had a problem. Now I am questioning if I should drain the T case and use 50 weight. What about a NP-435 trans? I used gear oil in that too!

 

[Torkman66]

Boy, sure did open up a can of worms (or oil) here. Great discussion. I went ahead and ordered the Valvoline VR1 50wt from Amazon. $10 a quart. I think after all the discussion, this is is safest route to take.

 

[ntsqd]

As far as I know the Bronco Dana 20 is the only anomaly requiring 50 wt. engine oil. Until you get into the alum cased t/c's (NP's & BW's) all others want gear lube.

If you REALLY want to open a can of worms, ask this question on the BobistheOilGuy.com forum.

 

[nvrstuk]

Another thing that we probably haven't addressed much is the evolution of oils since mid '60's or prior when the Dana 20s were first made and how some of these newer oils it might be absolutely fine for the alloys in the thrust washers now but others aren't???


The Dana 20 requires for its straight cut teeth (climbing/cling-i-ness) oil that will adhere. Old gear tooth designs, old thrust washer designs, etc make a huge difference for oil characteristics that you want for a 60+ yr old design. That's why synthetic's aren't the best for that application.

Anyway, love learning...

 

[ntsqd]

I'm not sold on the "no synthetics" thing. I bought a yota t/c case to build a doubler out of for Patch. It had the distinctive pinkish Redline gear lube in it (I asked the seller & he confirmed that it was Redline). That t/c sat for over a year in my garage waiting for me to get to it. The whole time that it sat there it continued to dribble pink gear lube onto the floor. I figured that it would eventually stop, but it never did. This was a t/c that was drained before it was removed from the truck. When I tore it down it still had pink gear lube in it's nooks and crannies.

I think that the general assumption is that because synthetics feel more slippery that they lack in clingyness when those two properties are distinctly different from each other.

 

[ba123]

I'm not sold on the "no synthetics" thing. I bought a yota t/c case to build a doubler out of for Patch. It had the distinctive pinkish Redline gear lube in it (I asked the seller & he confirmed that it was Redline). That t/c sat for over a year in my garage waiting for me to get to it. The whole time that it sat there it continued to dribble pink gear lube onto the floor. I figured that it would eventually stop, but it never did. This was a t/c that was drained before it was removed from the truck. When I tore it down it still had pink gear lube in it's nooks and crannies.

I think that the general assumption is that because synthetics feel more slippery that they lack in clingyness when those two properties are distinctly different from each other.

+1. I'm a synthetics guy. Ever since I worked in a race shop for a short time as a kid. It has never let me down.

Also, I found an old post...I'll try to find it again, but it was Paul (DirtDonk) mentioning that he ran synthetics in his D20 from 50k=175k miles and then sold it to Doug (904Bronco).

I'll try to find that again.

Oh, nvm, that was THIS thread, haha!