I have a D7F 92E and I mistakenly put 5 gal of hydraulic fluid in the transmission. I simply grabbed the wrong bucket and I'm wondering if anyone here can tell me if this is going to cause problems and If I should drain 37 gal out and replace the fluid. Based on the information below, I don't see how this could cause problems, but I'm not an expert on these older D7F machines as a lot of you members are and I would appreciate your inputs. The Trans holds 37 gal of oil so 5 gal is only 14%. From my manuals I see the Powershift Trans takes SAE 30 weight oil and the Hydraulic system takes SAE 10W if above 32 deg. If below 32 Deg the transmission and hydraulic system both take SAE 10W. So if I lived where it was below 32 deg, It would not be an issue, but I don't live in a colder region. What do you think I should do? Thanks in advance, Chuck
It all depends on your 10W "hydraulic" oil. If it is 10W oil that meets TO-4 specification then by mixing it with the oil already in there you still end up with a powertrain oil that maybe has a viscosity somewhere around SAE25, nothing to worry about. However if your hydraulic oil is not rated TO-4 then it does not contain the necessary additives for powertrain service and so the oil mixture in your transmission could have an additive package that is below the required level. The worst possible scenario could be a premature clutch failure.
Nige, Thanks for the info. The oil I normally use in the transmission has a TO-2 rating. I'm not sure of the rating on the hydraulic oil. I was going to buy the TO-4 oil but could only find it at the Cat dealer and the cost was twice as much as the TO-2 rated oil. I checked with the oil supplier and he said that back in 1975 when the machine was built they didn't have TO-4 rated lubricants. He said the materials they used in the clutches did not require the additives the new machines require and the TO-4 oil was not really necessary. What do you think? I hate to spend the money on 37 gal of oil, but I even more hate the thought of a transmission problem. Regards, Chuck
My apologies. The current specification is TO-4 and I quoted it without thinking. The transmission on your machine will run fine on TO-2 because that's what it was built to run on. However TO-2 as a spec to which manufacturers refer doesn't really exist any more and the modern-day replacement is TO-4. Your oil supplier is correct that TO-2 was the current spec back in 1975, however I would still ask the question if your hydraulic oil complies with TO-2 or not. If not the resulting mixture currently in your transmission may just be a bit short of additives even to make it TO-2 compliant. Depending on how you use the machine you might well be fine until the next oil change at which you could drain and refill with an acceptable specification of oil. Ask yourself this though, what's the comparative cost of 37 gallons of oil + a filter versus a transmission repair..? One question: How did the oil come to be 5 gallons low..? That seems an awful lot for just a top-up. You can buy TO-4 specification powertrain oil from every one of the major oil companies. As an example Mobiltrans HD series, Conoco Powerdrive series, Texaco Transmission & Drive Train series, Shell Spirax S4 series - all of them meet TO-4 spec so you don't have to buy it from your Cat Dealer. All of them list 10W, 30, & 50 viscosities of TO-4.
Run it, it's not enough to make a difference. You're splitting hairs with a 40 year old machine. Keep it clean and you'll be ahead of 90% of the other D7F's.
Nige, this is a good question. I don't use the machine much but I have noticed each time I have used it over the last 5 years or so, after starting in the morning, I would have to wait a while before I could shift it into forward or reverse. This wait had increased lately to maybe 5 minutes or so. I got on this forum and was told to make make sure the oil level was ok and to even add several extra gallons over the full mark. This is how I got to 5 gal to top it off. I also noticed the left final drive case was over full of oil. I found a thread on this forum where someone had the same problem. The over fullness of this guy's final was thought to have been caused by a leaky spur pinion seal or another seal. Since the final drive uses SAE 50 weight, I suppose getting transmission oil of a much lesser viscosity in the final drive case is not good. Any thoughts on what is going on here? Regards, Chuck