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brcathy


Joined: Jan 19, 2008
Points: 2

Ariens 11528 LE Gearcase Leak
Original Message   Jan 19, 2008 6:27 pm
Hello!

I am hoping that Snowmann can give me some advice. I recently purchased a brand new 11528 Snow Thro from a local dealer to replace my 23 year old ST724 (which STILL runs!). I have used the machine twice now and I am seeing gear case oil leak from the main shaft seal on the rear of the auger gear case. The funny thing is that the first time I used it nothing leaked and the second time it leaked AFTER I parked it for a day. So, when I noticed the leak, I used a rag and completely cleaned off the gear case so that I could see where the oil was coming from. Nothing leaked out for several days, but I noticed a puddle under the machine again today, and I checked it out with a mirror and discovered that the oil had come out of the main shaft seal. I checked the oil level and it was within range, but below the Full level.

I haven't run the machine for a couple weeks now, so I am wondering how the fluid is getting up there to leak out. And I am wondering if this is a common problem?? Can I use a thicker oil (like synthetic 80-90W)? Do the PRO units have the same sealing technique? If the PRO units seal better, then I will definitely trade.

The part that disspoints me about this is I bought a new machine so I wouldn't have problems like I did with my old one every winter. If I take this in for service, my fear is that I will have a new machine that has been rebuilt - not much better than what I already had.

Any advice you could forward would be appreciated!

Bryan

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Snowmann


Joined: Dec 3, 2003
Points: 494

Re: Ariens 11528 LE Gearcase Leak
Reply #1   Jan 19, 2008 7:16 pm
brcathy wrote:
Hello!

I am hoping that Snowmann can give me some advice. I recently purchased a brand new 11528 Snow Thro from a local dealer to replace my 23 year old ST724 (which STILL runs!). I have used the machine twice now and I am seeing gear case oil leak from the main shaft seal on the rear of the auger gear case. The funny thing is that the first time I used it nothing leaked and the second time it leaked AFTER I parked it for a day. So, when I noticed the leak, I used a rag and completely cleaned off the gear case so that I could see where the oil was coming from. Nothing leaked out for several days, but I noticed a puddle under the machine again today, and I checked it out with a mirror and discovered that the oil had come out of the main shaft seal. I checked the oil level and it was within range, but below the Full level.

I haven't run the machine for a couple weeks now, so I am wondering how the fluid is getting up there to leak out. And I am wondering if this is a common problem?? Can I use a thicker oil (like synthetic 80-90W)? Do the PRO units have the same sealing technique? If the PRO units seal better, then I will definitely trade.

The part that disspoints me about this is I bought a new machine so I wouldn't have problems like I did with my old one every winter. If I take this in for service, my fear is that I will have a new machine that has been rebuilt - not much better than what I already had.

Any advice you could forward would be appreciated!

Bryan



95% of reported (Ariens) oil leaks are from the filler plug or the rear oil seal, and both are typically more from having too high an oil level than anything else. Hydrostatic pressure on either isn't preferable from an application standpoint.

The original intent with the higher oil level is to eliminate dry starts by placing the oil level at the gear pitch line. Given the duty cycle of a snowblower gear box, this is not really necessary. The cooling effects of the larger sump capacity are also not really needed as the large worm gear design is very low-stress and cool running (aluminum castings also wick off the heat well, much better than cast iron). The fill used to be 8 ounces (right at the bottom of the filler plug hole). With the metering equipment being used this could sometimes get to 9. This has since been dropped to 6 ounces to keep some of these leaks from happening. If you put 4-5 inch blocks under the wheels (to tip the unit forward), drain the oil down to the filler screw hole level, and clean and reinstall the filler screw. This will put you at 6 ounces and should eliminate any rear seal penetration.

The alternative is to bring it to the dealer to try to shore up the rear seal. This may be counterproductive as there could be further issues due to thermal expansion (pressure differentials). While it has not created any problems that I've heard of, it is better in practice to equalize the pressure (a vent would do this) to keep from potetnially belching oil through the seals (6 psi or greater would need to occur). The rear oil seal is very hard to seal due to concentricity imperfections with the vertical parting line running through the seal bore. This would be true of all worm gearboxes with a parting line through the rear seal bore. Toro uses a square cut O-ring which seals far worse than an oil seal. They claim this is their “vent”. As their oil level is much lower, they have no problems.

The filler plug requires cleaning and resealing with each install. Same with the filler plug hole (the cleaning part anyway). Sometimes the screws start coming from the supplier a little stingy on the pre-applied Dri-loc sealant. This occasionally can cause a slow leaker out fo the box. As every gear case is pressure tested at ~5psi through the filler screw hole this cannot currently be caught at assembly with the current process.

The other 5% of the leakers are from cut lips on the rake shaft seals. This occurs when seal installation tools develop a burr and the lips are cut upon assembly. Although this is relatively rare, new seal installation tools are currently in process to keep this from happening.

I hope this helps.

PK

brcathy


Joined: Jan 19, 2008
Points: 2

Re: Ariens 11528 LE Gearcase Leak
Reply #2   Jan 20, 2008 8:27 am
Snowmann,

Thanks for your fast reply! I totally understand where you are coming from with the concentricity issue. I recently replaced the gears and rebuilt the case with on my 23 year old machine and it definitely was not concentric where the shaft exited the box. In fact, I had seen some of your earlier threads on the old cases and I brought my case parts into the machine shop at work and asked the machinist to face the surfaces and make them more true. The new bushings fit better and the entire mechanism seemed to go together very easily. I could not get the Mobil Monolith grease, so I installed new rake shaft seals and main shaft o-ring and used permatex in conjunction with the paper gasket on the halves. I switched that machine to the L-2 lubricant - it seeps out the back a little, but considering the age of the machine, I don't find it to be an issue.

I will take your suggestion to lower the oil level on the 11528. I much prefer that to doing an R & R on the front end. Although my Dealer is good, I know from experience that factory assembly is almost always best!

Thanks for your assistance!

Bryan

 

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