TO-30 Ferguson hydrolic oil

I have a 1953 Harry Ferguson TO-30. I am currently changing the fluids for the first time. What weight hydrolic oil can be used in the trans/rear cases? I live in Michigan. I believe the spec is 90 weight but I can only find 75/90 weight. I appreciate any help or advise.

I would put 75-90 in it and call it good... Those old
transmissions weren't very sensitive.

Check on the Harry Ferguson forum for info on using
15w40 engine oil instead of the original
recommendations. I have used it for about 5 years
and it works great.

Don't put 75/90 gear oil in it, it is way too heavy. Any good 15W-
40 engine oil will do.

(quoted from post at 18:14:56 02/10/15) Check on the Harry Ferguson forum for info on using
15w40 engine oil instead of the original
recommendations. I have used it for about 5 years
and it works great.

Click to expand...

In the transmission and rear end?

(quoted from post at 18:14:56 02/10/15) Check on the Harry Ferguson forum for info on using
15w40 engine oil instead of the original
recommendations. I have used it for about 5 years
and it works great.

Click to expand...

In the transmission and rear axle

In the trans and rear end ? 15w40 m ok tor oil in the trans and rear end?

Yes, 15w-40 engine oil works well. The original
90w gear oil proved to be too heavy. In cold
weather the 3 point will go into slow motion
until the oil gets warm.

The transmission, hydraulics, and rear end are
all connected. Fill both through the plug by the
shifter. Thinking it holds about 6 to 8 gallons.
Proper level is just to the bottom of the round
inspection covers below the seat. Fill it slowly
though, it takes a while to flow from the
transmission to the differential. Fill it too
fast, oil can come out the front seal and get in
the clutch!

Was there water in the transmission? Common
problem if stored outdoors. It gets in around the
shifter boot and condensation.

I don't know that I would use motor oil in it. At one time
that would have been fine, but gears need zinc, which has
been mostly eliminated from even diesel oil. I would call a
major oil company and see what universal hytran type fluid
they have in approximately the same weight as 15w40.

(quoted from post at 05:22:07 02/11/15) I don't know that I would use motor oil in it. At one time
that would have been fine, but gears need zinc, which has
been mostly eliminated from even diesel oil. I would call a
major oil company and see what universal hytran type fluid
they have in approximately the same weight as 15w40.

Click to expand...

Thank you very much, you have really helped me.

You can't use modern GL-4 or GL-5 hydraulic oil unless they are labeled yellow metal safe. The sulfur in some of them will eat away the bushins and stuff in your transmission because they are bronze. The original GL-1 is still available at Napa in 5 gallon buckets or at TSC in two gallon jugs. The oil at TSC is labeled Ford tractor mineral oil. When the Ferguson tractors were to be used in cold climates Ferguson recommended that a 10w30 engine oil be used. I have heard of some using the 15w40 diesel oil but remember that you hydraulic system does not have a filter. The pump was designed to let dirt fall into the sump, where it would remain until the pump was removed and cleaned out along with the housing. If you use a detergent motor oil it keeps the dirt in suspension and because you do not have a filter it will keep running the dirt thru the hydraulic pump and transmission. Lots of us are still running the GL-1 because it is safe for the transmission and hydraulic pump. Yes it is thick in cold temperatures, but I let my tractors warm up before using them, which is something that should be done anyway. I use GL-1 in both of my TO-20's.