Thinning of Transmission Fluid

[Dale J. Swanson]

The Transmission fluid in my l952 Ford 8N had a brownish color in it. I went to Tractor Supply and bought some All Mineral SAE 90 Ford Tractor Fluid. As I was pouring it in it appeared to me that it was very thick. It seems to me that you would have to run your tractor for quite awhile to let it warm up before you could begin to plow. I only put in 4 Gallons because I wanted to check with the experts on The Forum to see if it would be possible to thin this fluid out. Has anyone heard of using mineral spirits as a means of thinning it out? Will this thick fluid slow down the reaction time for raising & lowering my plow? I only use my tractor in the winter months when the temperature is below freezing. We are dealing with Lake Effect Snow at the moment here in Michigan. I would appreciate any help you can offer. Thanks
 

[Dean]

Ford originally specified 90W GL-1 "straight mineral oil" for the 9/2/8N tractors.

It is, indeed thick, when cold and you will need to operate the tractor for some time in cold weather before the hydraulic system responds normally.

CNH now specifies CNH 134D or equivalent, which is a much more modern oil and much less thick when cold. Use of 134D will result in much better cold weather performance.

Dean
 

[POPGUN]

I have ran a bushhog on 90 degree days for hours, pulled the dipstick touched the oil on it and well the oil was only 75 degrees. LOL,It takes more then I ever done to get the temp up so you would never get it in the winter.
 

[Machine249]

I just checked out a jug of the Tractor supply universal hydraulic fluid I have here. It meets the Ford 134d specs so I would, and I have, just put that in there and forget about it.
 

[wes(MI)]

Dale, I live in Midland, 45 min west of the bay, and run 80/90 ep gear lube all year. Winter operation on fire up is disengage PTO, depress clutch start and run, then walk away for 10-15 mins. Go back, engage PTO and go away for another 10 mins. It'll still be slow for awhile after that, but not nearly what it could be.
 

[TheOldHokie]

[tractorfix]

Just remember that whatever leaks you have with the thick stuff will turn into torrents with 134d
 

[Indiana Ken]

Well you already paid for it and have 4 gallons in the tractor. You can't take it back and ask for a refund...I would pour another gallon in and see how it works.

Dad had a 1952 8N and he/we never changed the trans/hyd lube for the winter. I am sure that would have been 90wt year round, for Northern Indiana. When I bought my 1950 8N I used it the first winter before I changed out the trans/hyd lube. I suspect it had 90 wt in it and I had no problem in the winter, or did I have to allow it to warm up before using. When I changed out the lube I went to CNH 134D based on the dealer's recommendation and that has not given any problems.

Back in 1950 the 8N Operators Manual stated: SAE 90 wt for temperatures above 32 F and SAE 80 wt for temperatures below 32 F. But ask yourself how many farmers drained out 5 gallons of lube to replace it with something a little lighter. I think - very few - they had better things to do.
 

[Jim in Eastern North Caro]

Must be one those fancy refrigerated bush hogs that can cool the oil from 90 to 75!
 

[rlpintx]

A few oz of marvel mystery oil might help. Used it in a VW gear box with 90 w helped those mornings it got down into the low 30s.
 

[souNdguy]

the thick stuff is the oem oil it was designed for.

if you fdon't like the cold weather properties.. switch to a utf.

I'd do that before thinning it.. however.. the idea of thinning gear oil has been used before.

i have a JD-B manual that states to add a pint of kerosene to the gear oil for winter use..
 

[POPGUN]

No such thing, the gears are cooler cause their kept in the shade,snicker.