Picked up the 80w-90 that it should take from the shelf but there was oil all over it so I put it back and grabbed the one behind it. Didn't even think to look. Got home put it in and then grabbed the bottle to put it up and saw that it was 85w-140 instead of the 80w-90 that I needed. Do I need to drain this out and put 80w-90 in or will it be ok until the next change?
Accidentally put 85w-140 in my rck48-15bx (48" Mower) gear case.
- Thread starter O'boy
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It will be fine. Gearboxes aren’t real picky. Put something slippery in and go.
RCW
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BX2360, FEL, MMM, BX2750D snowblower. 1953 Minneapolis Moline ZAU
Matt and Ford will know better, but don’t some folks use “corn grease” in gearboxes? Helps avoid leaks, and still does the job if memory serves.
I’d never heard of it until I got on OTT.
I’d never heard of it until I got on OTT.
Magicman
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No problem with the 85W140 and yes, OO 'corn grease' is the go-to if/when you have a weeping seal.
torch
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B7100HSD, B2789, B2550, B4672, 48" cultivator, homemade FEL and Cab
A mechanic once told me that he has seen a lot of blown differential seals in pickup trucks when people put in 85w-140 instead of the specified 80w-90. I don't know how that crosses over to a mower though.
NCL4701
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I have an old Howse 500 (not a high end machine but serviceable). Manual specs Shell Alvania 00 (cornhead grease), 85W140, or 140. My Dad ran it maybe 20 hours a year for 30 years after buying it well used. When I got it, I pulled the check plug and nothing came out. Asked him when he last changed the oil in the gearbox. He had never changed the oil or even checked the oil. I flushed it with kerosene and put 85W140 in it. That was about 50 hours ago. It runs just fine.
Agree with those who suggest so long as it has something in it, it should be fine. It’s not as sophisticated as even a differential.
Agree with those who suggest so long as it has something in it, it should be fine. It’s not as sophisticated as even a differential.
armylifer
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Heck, I did exactly that, on purpose. This part is opinion but I believe that the 85w-140 is a better lube than the 80w-90.
It's the end of the world, time to sell the mower and buy a new one.
I wouldn't dream of draining out the half quart of gearbox oil and replacing it with new 80W90. Think of the cost and time involved.
I'll give you $50 if you ship me the mower. FIRM. You can throw in the quart of 80W90 since you won't be using it anytime soon.
I wouldn't dream of draining out the half quart of gearbox oil and replacing it with new 80W90. Think of the cost and time involved.
I'll give you $50 if you ship me the mower. FIRM. You can throw in the quart of 80W90 since you won't be using it anytime soon.
I recently purchased a rototiller, which as you of course know has a similar gear box as a mower, driven by PTO. My rototiller actually calls for 85w 140 in the manual, in both the pto gear box and the larger side gear box. I think you will be fine. The oil is a little "thicker" than 80w 90, and will handle heat better. many 85w 140 gear oils also have "EP" or "extreme pressure" additives. a lot of 80w90 gera oils have "L/S" or "limited slip" additives. So the real differences as I see it are as follows:
80-90 gear oil is not as thick, so it is more fluid. (only slightly though - hard to tell difference dipping your finger in it) because of its lighter/thinner weight it isn't as good in high heat or perhaps in areas where the gears in a box are experiencing a lot of stress. This is likely why my rototiller calls for 85w140 and your mower calls for 80w90. Rototillers tend to hit things like rocks and can encounter a lot of resistance and knocks, causing this to transfer some of that force into the gears of the unit, so they recommend a heavier oil that is better under heat and extreme pressure. Mowers by contrast shouldn't be encountering the same resistance and "jolts" to the rotational system, so less heat, less stress, and so they recommend a slightly lighter, more slippery, more fluid oil. I have seen some rototillers, especially older ones, that did call for 80w90 oil however, so really the differences in these oils is likely fairly small.
So really gear oil is gear oil. One is just a tad heavier, tad thicker, tad better under heat and extreme pressure. The other is a little lighter, little more fluid, little more "slippery". They could largely be interchangeable in rototiller / mower gear boxes. If you want to play it super safe and are concerned about the oil, then you know the main concern with using this oil over the recommended oil is that the oil you have in there is heavier. Let your mower idle a tad before using it. Put it up to 540 pto and let it run for a minute before mowing. May not help much, but the idea is of course to let that slightly thicker oil warm up a tad, so it is moving better, and get the gears nice and coated, before dropping it down and go to cutting.
80-90 gear oil is not as thick, so it is more fluid. (only slightly though - hard to tell difference dipping your finger in it) because of its lighter/thinner weight it isn't as good in high heat or perhaps in areas where the gears in a box are experiencing a lot of stress. This is likely why my rototiller calls for 85w140 and your mower calls for 80w90. Rototillers tend to hit things like rocks and can encounter a lot of resistance and knocks, causing this to transfer some of that force into the gears of the unit, so they recommend a heavier oil that is better under heat and extreme pressure. Mowers by contrast shouldn't be encountering the same resistance and "jolts" to the rotational system, so less heat, less stress, and so they recommend a slightly lighter, more slippery, more fluid oil. I have seen some rototillers, especially older ones, that did call for 80w90 oil however, so really the differences in these oils is likely fairly small.
So really gear oil is gear oil. One is just a tad heavier, tad thicker, tad better under heat and extreme pressure. The other is a little lighter, little more fluid, little more "slippery". They could largely be interchangeable in rototiller / mower gear boxes. If you want to play it super safe and are concerned about the oil, then you know the main concern with using this oil over the recommended oil is that the oil you have in there is heavier. Let your mower idle a tad before using it. Put it up to 540 pto and let it run for a minute before mowing. May not help much, but the idea is of course to let that slightly thicker oil warm up a tad, so it is moving better, and get the gears nice and coated, before dropping it down and go to cutting.
I just came in from getting my new Sicma tiller ready to go tomorrow for a 1st run. 'Just because' I checked the gearbox. Not a drop in it. I would normally check something like that as a matter of course but the pto yokes came well lubed and I thought I was wasting my time.
The manual says 80-90 wt oil. I have a container of Mobil 1 synthetic 75-90 and in it went.
I'm pretty much in the camp that the gearbox needs oil and anything close will work fine. Especially when you change oil more often than necessary like I do.
The manual says 80-90 wt oil. I have a container of Mobil 1 synthetic 75-90 and in it went.
I'm pretty much in the camp that the gearbox needs oil and anything close will work fine. Especially when you change oil more often than necessary like I do.