Fluids Question

[ng19delta]

I have a quick question regarding fluids for the WC51 Transmission, Transfer Case & Differentials-

Owing to the relative disappearance of GL4 90wt., (Available, but through specialty suppliers), I am seeking a viable alternative. One friend said he uses 90wt GL1 pure mineral oil for his Willys MB T-84 transmission, which has the synchros in it. He uses this based on it being the approved lubricant for all Ford tractors(!) through 1950 or so.

I am considering using the same for the WC transmission, as it does not need to be hypoid. I don't know if GL5 would affect the transmission at all(does not appear to be any yellow metal in it) but I'm trying to avoid issues. (I have had GL5 in the trans since I put it back together, about 3 years ago)

Also, I think GL5 is ok/necessary for the differentials, as it needs the Hypoid element for the high pressure of the gears...

Am I correct? What would be the recommended juices? I'm planning to refill the transmission(need to regasket the side plates) and differentials...

Thanks!
Scott

[Richard Starr]

Interesting that no one has replied - I am also looking for an answer to this question!

I was pretty sure there would be lots of responses and some kind of consensus answer. I have a vague recollection that bronze bushings require a certain type of gear oil and there is a difference between what you should put in the transfer case, and in the diffs, but as I say, no more than vague...

[Andersun]

I have been using 80W-90 Gear Oil for many years in Florida. No problems at all except for some of it ends up on the garage floor.

[Lang]

I don't think it is as critical as all that - requiring particular brands etc.

Modern oils are far superior to the originals.

Toyota Landcruisers and Nissan Patrols use auto transmission fluid in their mechanical transfer cases and normal oil in the gearbox.

Morey's oil stabiliser recommends 100% in transfer cases, no oil, and I have had great success with that in my WC53 over 10,000km high speed highway running. Seems to run cooler and definitely much quieter.

I think any code modern gear oil of the right grade would be more than adequate for a WW2 Dodge transfer. The multi grades keep their consistency constant over a very wide heat range while the old single grade was all downhill. If you read the fine-print on the bottle label you will find nearly everything covers both straight and hypoid gears these days.

Lang

[June J]

Hi Scott,
GL5 is fine. GL5 contains an extreme pressure additive that contains sulphur. This sulphur will attack any yellow metals so it is not recommended where there ate synchro units and or bronze thrust washers present, fortunately there are none in the Dodge gear box or transfer case. This oil is also fine for your differentials and steering gear.

Cheers

Ian

[Kaegi]

napa can order GL4 if you want. the oil weight needed depends on your climate. if you live in Alaska then you need to run 30 weight in the winter and 80/90 in the summer. in TX you can run 140 year round. I likehte GL4 better than GL 5 as the GL 4 doesn't thin out as much when hot. the stores just have GL5 because it is needed in anti spin differentials which have been very common for decades