Outdoor Power Equipment (Lawn Mowers, Snow Blowers, Chain Saws and more) Discussions

Hi all,

I just bought a 1993 (I think?) Ariens ST824. Model 924082, serial 0040XX.

The good news: Paid $150, the augers weren't turning (the belt had come off, and seems like it needs to be replaced). It starts & runs fine, and has electric start. The engine showed ~120-130 psi when cranking it with the electric starter, and ~60 psi when pulling it by hand (I don't know whether those are good or bad). It has a differential, rather than the simple pin-through-the-axle setup of my MTD. I thought that was a cool surprise, I didn't expect a differential. Is that common on the ST824's, or did I get lucky? The differential works fine. It's a weird feeling being able to just steer it.  I get the impression that the previous owner gave it some grease occasionally, since the gearbox area seems well lubricated. The person I bought it from just got it recently, so I don't know its history.

The less-good news: It has a fair bit of rust, unfortunately (may have been stored outside?). But it seems solid. There are two areas that concern me so far.

One is that the big gear on the differential can skip against the teeth of the mating sprocket. There appears to be quite a bit of play in the wheel bearing on that side (the bearing at the other end of the shaft, for the right wheel, seems a bit better). So I think the shaft is being allowed to move too far away from the mating sprocket, and it's able to skip. Is this common? It looks to me like replacing the wheel bearing should do quite a bit to help make the gears tight again. Am I right? Is that a difficult job? Special tools needed, etc? It sounds like a tapered roll pin has to come out, from glancing at the service manual. 

The other issue is that there is play between the two halves of the unit. The tractor half, and the snowblower half. The big bolts at the top of the frame, which join the two, were loose, and able to bang back & forth. It seems that it's been used like that for a while now, unfortunately. One of those bolts can't be tightened, the nut (below the frame) just spins. I'm having a hard time figuring out a part number for that nut. As a result of those bolts being loose, I assume, the bottom area, where the two halves join, has also worn. There is a rod in the tractor half which slips into a groove in the snow blower half. That groove has opened (I think) and the rod has worn smaller. So there is play down there as well. I'm not sure if there's a good way to try and take up that play, with some kind of bushing perhaps.

So I think I need at least some belts, a friction disk, probably one wheel bearing (I'd prefer to leave the right-side one alone, if possible), and I'm sure some other random parts. Maybe I can figure out some way to tighten up that rod-to-groove fit at the bottom.

Does this sound like it's worth fixing up? I'm looking for something reliable and durable to replace my MTD 8 hp, 26". I just don't know whether the issues described above should really never happen, and therefore this machine has been put through a LOT. And that maybe I should look for a different one. I don't have a problem fixing this stuff, as long as a handy homeowner can replace the bearing, and so on. I just don't want to start down a rabbit hole.

Thank you for any feedback or suggestions!

Got to do some more work on it tonight. Checked the auger gearbox oil level, using the test in the manual (raise the back 6", etc). It passed the test, has enough oil to wet the fill plug again. The augers each appear to be able to move on the auger shaft, and are not rusted in-place.

I removed both wheels and the axle. Drove out the roll pin by the right wheel. The bearings were quite worn, there is a lot of play in them. When I removed the left wheel, and went to remove the differential lock assembly, I found that the 1/4-20 grade 8 bolt, which holds it in place, had previously broken in half. I did not see any roll pins in that area that I had to remove. After sliding out the broken bolt, that differential knob assembly slid off. I have not tried to open it (have no need to).

I'm letting some PB Blaster sit on the nuts that hold the Bearing Retainers in place. I wish they had something besides flat-blade screwdriver heads on them. Very awkward to reach and hold. Now I'm waiting for the replacement bearings, etc, to ship.

Those flat head screws on the back of the bearing retainers "should" hold themselves in place.  They have little ribs on them that push into the frame similar to how wheel studs on an automobile are.  The auger bushings up front have the same type of screws on the inside.  That being said, a couple of mine were loose enough that a screwdriver was needed.

Sometimes people take of the locking hub loose the pin and put a bolt in it's place.  The pin for the hub is a solid pin.  Not a roll pin.  The bolt will work, but I would
go ahead and order a pin.  It holds the hub onto the shaft with a much snugger fit. 
Those small bolts can be a pain if they have lost their self holding power in the frame.  The good thing is once you get your new bearings installed those bolts won't
have to come out again for a long time.

Hmmm, OK. The screws that hold the bearing retainers might stay put. But I tried one last night, turned the nut, and the screw head turned as well. Tried to hold it with a screwdriver, tried again, and the screw turned again. Maybe the others will stay in-place, I don't know. If they all try and turn in the frame, is there a reason I couldn't replace them with hex heads, once they're out? At least I could hold those with a box end wrench.

On the note of the pin/bolt, maybe I didn't explain it well. I'm referring to a bolt that goes perpendicular to the axle shaft, and holds the Lockout Hub in place. It would keep it from sliding off the shaft when you go to pull the knob for locking/unlocking the differential. It's shown in the Parts Manual for 924082, as Item 42, in the Reduction Drive section, described as 1/4-20x2" cap screw, grade 8. I'm not referring to the spring-loaded pin that slips into the hub, to lock the differential.

I do see an Item 38, Bshg-Slv, listed on the drawing. I don't *recall* noticing something like that last night. Where does that bushing go? It's shown between the differential and the left-hand axle. Might it have stayed in with the bearing? I just want to make sure I'm not somehow missing a part. There is some wear on the axles where the bearings sit, unfortunately. I will try them as-is with the new bearings, since I don't want to go too crazy with just replacing everything. Thank you again for all the help.

Some models used bushings and some used bearings for the axles.  Most of the parts lists are for multiple models so they just show both parts.  That being said, there are 2 small bushings on the short side hub axle where the 2 pieces slide over each other.  These are pressed in pretty tight though as I had some trouble getting mine out to replace.  You probably could use hex bolts in place of the screws, however, I believe they will stick out too far on the side with the differential gear.  I think to remove one of my screws I had to hold the screw with the screwdriver at a 90 degree angle so instead of using the tip of the screwdriver I was actually using the side of it.

Keep in mind that mine is a 1977 model and probably a little different.

RedOctobyr wrote:  As was already stated, a regular bolt won't work because of the clearance issue with the diff.  You could try using allen cap head bolts.  They have a head that isn't as tall as
a hex head bolt.  What I have done in the past when I've had the issue with the heads spinning.  Was to remove the four bolts.  Clean the threads real well, make sure the
the nuts spin on without any effort.  Put the bolts back in and start tighten down the nuts.  Sometimes when they go back in the holes in a little different position.  They will grab in the holes once again just enough to allow the head to come in contact with the steel frame. And if you hold the heads with the screw driver.  They will tighten down fine without spinning the heads.

Sorry about the misinformation.  Yours is supposed to have a bolt holding the locking hub on the axle.  Mine which I guess is older uses a pin.

There are bushing inside both ends of the left hand short axle/housing. Slide it on the axle half way, (locking hub end first) and see if it's sloppy on the shaft. 
Then slide it on half way (correct end first) and see if it's sloppy on the shaft.  Hope that makes sense?

Tried the rest of the bearing flange screws. 3 came off (the screws stayed put, held into the frame). The other 5 just spun :) I managed to get one of them off, using a 90-degree screwdriver. The others will all probably be Dremeled off. If I can find maybe some button head socket cap screws, or possibly low head socket cap screws, I might try to install those as replacements. At least I could hold the screws with an Allen wrench, vs a screwdriver :) If the threads weren't so rusted up, they probably would have come off OK. Removed one axle bearing, it is a sloppy, worn-out mess.

I looked a bit at bushings on the axle. The outside end of the left axle is snug, when I install it backwards. It also felt OK when installed normally. I didn't dig around in the grease on the inside of the left axle, trying to see if I could find a hidden bushing buried in there :)

I have to say, the grease fittings seem to be a big help. Much of what I've tried to remove, if it's not exposed threads, has been lubricated, and came off OK. This may be my only piece of OPE with grease fittings (my Craftsman tractor might have a one or two); it's a nice feature. I'm hoping to find some good, suitable grease, which won't get too solid/sticky at low temperatures. I've seen marine and snowmobile greases mentioned. I found marine grease at Lowes. Not sure where to find snowmobile grease, or something else that's meant for low temperatures. I've used wheel bearing grease on my MTD (it's what I had), on the shaft that the friction disk slides on. That must be too sticky, because the shifter lever is quite stiff on that one, by comparison, and the grease feels tacky on the shaft.

RedOctobyr wrote:
Yea those little bolts for the bearing flanges can be a pain.  And your right, it's the rust that messes things up  I know Ace Hardware carries allen cap bolts. I've bought them there before. I wouldn't even be surprised if
you could find replacement bolts as well.  Ace Hardware has an amazing assortment of specialty nuts, bolts and small hardware.  The best I've ever run across.

A black moly grease works pretty well for the axles.  On the shaft for the friction disk slide, I guess you talking about the hex shaped one?.
 I always spray some carb cleaner on a rag and clean off the shaft real well.  Doing that alone will make the thing slide easily.  Just a light coat of white litium or even the
moly grease will work.  Your right, axle grease is too thick and sticky.  Just don't put much on it, just a light coat.  The shaft spins pretty fast and if the lube slings off it can get on the friction drive disk.  Not good.  Your going to have a nice blower when your finished.  All the parts your replacing are probably original.  So they lasted what 20+ years.  That's pretty good.

Just wanted to post an update on how this is progressing.

I cut off the remaining screws for the axle bearing retainers. Replaced them with stainless flanged button head cap screws, which have the same head height as the stock screws. So they should not interfere with the differential. You *need* to hold the heads now when tightening/loosening them, but at least an Allen wrench works nicely. Once the stock rusty ones spun in the frame, I couldn't do much to hold them still even with a 90 degree screwdriver. I did use a hex head bolt on one of the right-hand ones, since I couldn't fit an allen wrench between the auger pulley and the screw head.

Replaced the axle bearings, which were completely toast. Unfortunately, they had started to move relative to the axle shaft, and wore the shafts down from ~1.125" to more like 1.100". For the time being, I wrapped some stainless shim stock around the shafts, underneath the bearings, to try and take up some of the slop. If the machine proves its worth this winter, maybe I'll try a more permanent fix in the spring. The most permanent solution would be to weld up the areas of the shafts, then turn them back down to size. Replacing them would also work, but they're expensive :)

Also replaced the bearing for the hex shaft that the friction disk rides on. That was also worn out. I bought the bushings to replace them for the pinion shaft (the one that the mating gear for the differential rides on). But in trying to tap that shaft out of the frame, it was getting tight. I'd removed the roll pin at the right-hand side, but I was concerned that if I got the shaft out, I'd never get it back in without disassembling a bunch more stuff. And the bushings are in OK shape, so I left them for now.

Adjusted the Reduction Shaft's location to snug up the tension on both chains. Managed to find some snowmobile grease, so greased all the fittings in the transmission with that. Apologies for not using the black moly grease you suggested, jrtrebor; reading up on grease suggestions here showed a number of people suggesting marine or snowmobile grease. The snowmobile grease seemed like it ought to stay useful at cold temps, so I used that.

The new axle bearings appear to have helped tighten up the mesh between the differential and the sprocket. So that's good. I'll find out more when I can do some more testing.

Also replaced the auger belt, and tried the augers. After 5-10 seconds of running at low speed, I started seeing smoke. Immediately shut everything off, and found that the auger pulley is loose on the shaft, and had slid towards the engine/tractor half, and was rubbing against the differential. Split the halves tonight, and the auger pulley and hub slipped right off the shaft. The woodruff key is intact. The two allen setscrews in the hub are stuck at the moment, so have them soaking with PB Blaster. Is it typically the hub that people have said is difficult to remove from the shaft? I think so, but maybe I'm wrong. If so, I guess I don't have that problem, at least :) There is some play between the auger shaft and the auger bearing, but I'm planning to leave that alone for the moment. Replaced the big Nut Retainers, which were both broken. Thanks for that part number, jrtrebor.

I know it's a whole other discussion to itself, but any suggestions on something to help protect the rusted & exposed areas for this winter? If I try any repainting, it will likely be in the spring. Thank you again for all your help.

Sounds like your coming along.  You will have a good blower when your through.  As far as the rust goes for this season.  I would just remove any loose stuff.  Wire brush, wire wheel on a drill.
Whatever works.  Dust off the areas, wipe them down.  Carb spray on a rag works well.  Coat the areas with a rust stopper spray.  Auto stores have it and I believe home depot.  Comes in a spray can.
Goes on clear then turns black where ever there is rust.  Then hit those spots again with a red oxide primer that's the brown stuff.   Rust-Oleum is what I normally use. Your then good for the winter.   I may not be as pretty as you like but it will keep the rust at bay until next spring.
That's about the best you can do.