Running gear fluids

[preaction]

I am changing all fluids and the shop manual states 90 weight for the transfer case is there a modern equivalent that can be used ?

[Dutch]

I plan to just use valvoline 80w-90 gear lube, or pick the brand of your choice. They all make 90 weight gear oil. The same stuff that goes in the differentials and transmission.

[CSCameron]

I'm using Valvoline 85-140 in my diffs/transfer/tranny.

[712edf]

It seems like I read either here or on one of the other PW/dodge forums that the synthetic stuff like Royal Purple will lower the operating temperature of these old transfer cases.

Valvoline is what I use, my truck doesn't get driven daily nor long distances.

Bucky

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So its only the winch that needs a special lube ?

[Desoto61]

Yes, most modern lubricants are way better than their old counterparts, and will easily work in the old stuff (usually better) as long as the viscosity range is similar.

However the worm gear setup in the winch is far different than the rest of the gearboxes, as there's a lot of sliding friction. Plus the bronze bull gear can react badly to sulfur containing lubricants.

[CSCameron]

Several (including me) are running Corn Head Grease in the winch and steering box.

Clark

[Desoto61]

There was a really good write up about different winch lubricants posted here a while back. May be in the archives now though.

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Gl-5

I wasn't sure about this rating for the heavy weight oils.

[Doc Dave]

The TC is notorious about leaking. Thinner oils will leak out unless yours is really "tight". I just rebuilt mine with Wayne in MD's help and it leaks very little now, but due to this tendency I use the 85-140 oil in it.
In the transmission, I use straight weight engine oil, 50. This is the same "weight" as 90 weight gear oil, but without the sulfur in the gear oil lubricants.
This was a tip by Charles Talbert of M series rebuilds company.
I use corn head grease in the steering box, but use the Lubriplate winch oil lubricant in the winch. I am concerned the corn head grease might not flow across and around the different areas as well as necessary in the winch. Might not be an issue though.

[Nick]

The TC is notorious about leaking. Thinner oils will leak out unless yours is really "tight". I just rebuilt mine with Wayne in MD's help and it leaks very little now, but due to this tendency I use the 85-140 oil in it.
In the transmission, I use straight weight engine oil, 50. This is the same "weight" as 90 weight gear oil, but without the sulfur in the gear oil lubricants.
This was a tip by Charles Talbert of M series rebuilds company.
I use corn head grease in the steering box, but use the Lubriplate winch oil lubricant in the winch. I am concerned the corn head grease might not flow across and around the different areas as well as necessary in the winch. Might not be an issue though.

Thats funny, I have 85/140 in my transmission, transfer case and both diffs. The only thing that leaks, other than the rear diff due to the stripped studs at the bottom of the case, is the transmission and PTO. Transfer case is bone dry. I also have corn head grease in the steering box. I put a zero in the cap and grease gunned it in there.

[preaction]

85-140

Is this the same oil that's labeled for use in rear diffs ?