# Old Ariens gear box leaking



## bmac2985 (Nov 30, 2008)

I have an old Ariens snowblower (model 922018). Changed the gear box fluid (used mp80/90ep gear lube) and started it up and its leaking out of the shaft that turns it but not the seals to the augers. 

The parts list at Ariens shows a seal that may have worn out. Wondering how hard it is to change it. 

Or, is the oil to lightweight (Ariens recommends mp90 gear lube) and is flushing past the seal.

Any ideas???

Brian


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## Basementgeek (Feb 7, 2005)

Hi and welcome to the forum :wave:

A few questions first.

Why did you change it to start with?

Now did you drain it ?

Could you possible over filled it ?

Does it have a vent and is it clear?

80/90 weight gear lube sounds about right.

Guessing that it require total disassembly to replace the seal.

BG


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## MrChooks (Apr 19, 2008)

:wave: I agree with BG - if the seal is gone, whilst they are inexpensive - you will likely need to dismantle the gearbox to replace it - not hard but a bit of a PiA:sigh:

These gearboxes are usually worm and gear drives and the input shaft is the high speed shaft, so if a seal is likely to go - that will be the one :sigh:, BUT if it wasn't leaking before you added oil - then it should still be sealing OK, as a slightly different oil grade shouldn't make much difference to the seal's sealing properties.

The important issue is that as the gearbox operates, the oil inside heats up quite a bit and expands - so if you have overfilled the gearbox - the excess oil will be forced past the seal until the level falls back to its design maximum and then it should stop leaking alll by itself :grin:. Similarly, if the "breather hole" is blocked, then the expanding heated air inside the gearbox can force oil past the seal. So if the gearbox wasn't leaking beforehand - then I would suspect an overfill and / or blocked breather.

If it was leaking and you haven't overfilled, then you will need to get the g/box out and replace the seal :sigh:


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## bmac2985 (Nov 30, 2008)

Thanks for the replies guys. Good info.

I bought the old machine from a guy that inherited it. So I changed the oil
not knowing when it was last changed. Figured it only help it. And I don't think it was leaking either.

This design is pretty solid-I drained all the old gear lube out of two square head drain plugs (2 of them) right in the front /lower front of the gear box.

I put about 5 ounces in-manual called for it-I could have overfilled- but pretty sure I didn't. I'll drain and refill again.

Not sure if it has a vent hole. If it does I don't know where its at-do you???

What do you guys think about going over to a thicker bentonite based grease to solve the problem??? 

I'm not worried about taking out the gear box just don't want to have to open the box itself. Looking at Ariens Parts locator, that seal looks like it could be grabbed and replaced pretty easily- 
of course it could be a whole can of worms too.


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## MrChooks (Apr 19, 2008)

:wave: Hi bmac.

OK the easy questions 1st - the breather hole (if the gearbox has one) will be at the top of the gearbox - probably in the filler plug or somewhere nearby at the very top of the gearbox.

If the seal is really shot - then changing to thicker oil probably won't do a lot of good and you *CANNOT replace the gear oil with grease*. The worm drive (input shaft) spins very fast (probably about 3000+rpm) and the mating gear surfaces need a constant lubricant film that grease generally cannot provide to fast moving parts. The oil also acts as a heat transfer mechanism - helping to keep the gears cool. - So if you just filled it up with grease - it will work for a while - but ultimately you will trash the gearbox :4-thatsba

If the gearbox was full of oil initially - then that would indicate that the seal was working OK. The only issue here is if the machine had been standing idle for a very long time (like years!!), then it is possible that the seal was "bound" to the input shaft and when it was started - that can tear the seal. - BUT as I said - that usually only happens if the seal and shaft were idle for a very very long time.

I wouldn't bother changing the oil again - just check the level (if you can see into the filler hole, about 3/4+ full should be enough) and use the machine for a while and at the end of each use - check the oil again. If you have overfilled it - then once the surplus oil is expelled - the leaking will stop by itself :laugh:

If it keeps leaking and the levels keep dropping - then its a new oil seal I'm afraid :sigh: but it's not that bigger deal, -just a bit fiddly:sigh:

If you are worried about doing the seal change yourself - then once you have the box out - getting you local outdoor equipment / mower shop repair guy should be able to do it fairly cheaply - especially if you delivery the gearbox to him, so all he has to do, is put it on his bench and do the seal change :smile:


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## bmac2985 (Nov 30, 2008)

thanks Mr. Chooks.

Sounds like good advice. I see a lot of people are using the grease to pack 

the gear box. Was actually going to do that myself since the 

manufacturers recommend it for this application. Now I might reconsider.

I think I'll do exactly what you said...Look for a vent-clear it if I find one- 

and watch the oil level. Not sure how long it sat, but it only started leaking 

when I changed the oil. And there was plenty of oil to drain. 

Lets see what happens, I'll keep you posted.

Thanks again, Brian


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## MrChooks (Apr 19, 2008)

:wave:bmac - happy to help - 

If the manufacturers actually recommend packing the gearbox with grease then I guess it would be OK - but I have never heard of this before - so would want to see the recommendation in writing from the g/box maker before I even entertained the idea. 

I guess it would be a viable option if the input shaft speed was quite low (such as on a different application -like industrial pot stirrers etc) - but where the input shaft speed is high I would be very careful about relying on grease to lube gear faces. (see my PS at end of post)

Anyway - lets see what happens after a few more uses of your machine - if it wasn't leaking before and was going OK - I wouldn't be at all surprised if it "spat out" a little more oil then stopped leaking altogether:grin:

Let us all know how you get on

PS - A bit on the theory behind gear oil - Gear oils are designed and spec-ed to ensure they have very high film strengths even at high temperatures and operating speeds. They are designed to ensure that there is NO metal to metal contact between the gear faces :4-thatsba - They do this by having a film strength that is so high that the gear faces are unable to squeeze the all oil film out from between the gear teeth mating faces as they engage. Grease will do a similar thing, but at high speeds it is much harder to ensure that the entire gear face has an adequate film to prevent metal to metal contact - and it is metal to metal contact that destroys the hard facing on the gear teeth and once that happens - it's bye bye gears


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## Basementgeek (Feb 7, 2005)

Thinking about this again, there is probably is no vent . There should be no heat build up as the gear box is always in the snow. That ought to keep it cool.

If the input shaft comes in on the top part of the gear, it will probably quit leaking once the level drops some. Just keep an eye on it. If it calls for 5 oz, it will probably be ok on 4oz.

If you decide to replace it make sure that there are parts available for it first. 

I would try to live with it, adding a couple Ounces of lube is certainly easier that shoveling snow.

BG


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## bmac2985 (Nov 30, 2008)

I like you guys, you speak reason (and actually give answers).

Ok, after talking to a mechanic on diesel engines he states pack with grease as a last resort. It will hold up but is only a temp fix. He said simply to watch the oil and see if it drops-like you guys suggest- and change the seal if things go south. He stated however, if there was no vent to vent it by drilling a hole in the plug or leaving it out until the grease found its level-I'm not going to pusuh out point- then cap it. 

I agree with you...It makes no sense why it would leak now-after 30+ years- until I change the oil.

I'll watch it and report back.

Thanks guys, got more ?'s coming...especially about bushings.

Brian


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## MrChooks (Apr 19, 2008)

:wave:No probs Brian - that's what we're all here for.

We all await with "baited breathe" for the next challenge!!!:laugh:


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## SABL (Jul 4, 2008)

If the seal did not leak until you changed the gear oil, you may have commited the ultimate sin when dealing with older engines and drive-train components. I, myself, performed this very sin many years age and have never repeated it since. The victim was a Ferguson TO20 tractor.... the sin was changing the oil and filter. OK, oil and filter are routine maintenance so that was not the real problem. What turned it into a sin was the replacement oil that I used.... detergent oil!! My poor old "ferkuson" leaked from every place possible.... even the valve stem oil seals which made spark plug fouling occur within an hour or so of use. The clutch disc became saturated with oil from the rear seal. That's what I call a major boo-boo..... 

The seals in older machines were made of different materials than what is used today and were prone to wear. Non-detergent fluids would stick to any dust or grime that settled around the seal as it wore so slowly that it was not noticeable. Kind of like a scab on a wound. The introduction of detergents in today's oils will break the "clotting" action of the scab that took many years to form on the seal and you get leakage as an after-effect. 

I'm willing to bet that the owner's manual for you machine recommends 90 weight non-detergent oil for the gearbox and the 80/90 might have detergents that have destroyed the "sludge" that kept the unit reasonably sealed.

If and when you replace the seal on the mainshaft, it might be wise to also replace the seals on the output shafts as well. The cleansing action has not reached those seals, yet, but will do so eventually with use.

You mentioned bushings. If you're talking about the same machine, I would finish the season while keeping an eye on the gear oil level and make the snowblower an off-season project. Also, if the replacement seals are identical in material for the originals use the same fluid that was recommended and kept it going for many years.


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## MrChooks (Apr 19, 2008)

:wave: SABL - I bet I would have heard you "cussing" from here about your poor old Fergie! at the time:laugh: - and I am afraid that's what happens if you put "diesel engine oils" into gasoline engines.

Brian - hopefully you used "Gear Oil", as gear oils generally DO NOT contain detergents. These are put into engine oils (especially diesel engine oils) to keep combustion by products in suspension so as not to sludge up the sump and oil passages and to ensure they are carried to the oil filter/s for removal from the engine oil flow

I absolutely agree with my colleague SABL, in that if / when, you do have the input shaft seal replaced - replace them all. The seals cost just a few $s each; but the labour costs / effort to put them in is much more - so if you strip the g/box down - do ALL the seals and they will last you a lifetime.

Anyway - let's see if your oil leak problem subsides - you might be lucky and once any surplus oil is expelled - it might stop by itself :grin:


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