Hi, this is my first post. After looking endlessly for information on how to adjust the friction drive transmission on my Toro 824, I ended up doing it the old fashioned way; I just got in there and figured it out!
My problem was that my Toro slowly lost drive power to the wheels. It got to the point that it would only move in first gear forward and barely in reverse. I got this machine used and had no manuals to refer to for adjustments so I tried some of the no brainer approaches (lengthen/shorten the shift rods) and only made things worse. I checked and dressed the drive belts. That part is important, a slipping belt will give some of the same symptoms I was experiencing. The Traction drive belt is adjusted (and easily treated with belt dressing) from beneath a plastic cover located between the motor and the auger housing; two bolts to remove. The lower of the two bolts holding the idler wheel is slotted, allowing you to move the wheel forward to tighten the belt. Note: None of the adjustments to the transmission rods or levers has any affect on the traction drive belt tension. The auger/impeller belt on the other hand is adjusted ONLY by the actuating lever; lengthen or shorten the clevis below the handlebars.
When you're satisfied that the belts are snug and not slipping, take it for a test drive; you shouldn't be able to hold the unit back without the wheels spinning or the motor stalling. If the drive is still weak (as mine was) it's time to go underneath. I learned from studying an exploded picture from an online parts book how this friction drive system works: There are two rotating friction disks which are hardmounted to the mainshaft. The larger disk, just behind the impeller, provides forward movement. The smaller disk which gives us reverse is located at the opposite end of the shaft near the rear of the drivecase. There is a drive wheel with a rubber surface that shuttles between the two disks and when it engages one of the rotating friction disks, it turns the hex shaft and by way of a gear-reducing chain, the axel shaft. Don't be afraid to drop the bottom cover (four bolts) and take a look; it's a devilishly simple setup.
As I mentioned, I had already monkeyed with the adjustments available on the transmission lever/rods; didn't help. Once I had the bottom opened up and watched what happened when the levers were moved, I was easily able to see why I wasn't getting solid drive. The drive wheel, the one with the rubber cover, had come to the limit of it's travel and was just barely contacting the friction disk. While this would give weak forward drive in first gear, any strain or a higher gear, the machine would stop due to the drive wheel slipping on the friction disk. I don't know how much meat (rubber) the drive wheel has when new, but looking at mine there was still a quarter inch or so of usable driver left so I thought "how do I increase the travel and make solid contact?". I was about to the end of the adjustment on the clevis at the rod and the pivot that moved the wheel back and forth was hitting the limits of the slot in the case. I could see that the pivot would move more if it were allowed to, so I increased the length of the slot in the case. This by itself, did let the drive wheel travel closer to the friction disk and I couldn't make it slip by hand. I think, ok, It's gonna go now. I left the covers off and tried an in-shop smoke test. I fired it up and tried to take off in third gear, nope. Second, yeah, kinda. First, yes and a lot stronger; but I could still stop it without to much effort. Back to the drawing board.......
Ok, so I flipped her up again (by the way, I found that a pair of jack stands under the axels will make the bottom end accessible without repeatedly draining the gas) and looked some more. I studied the way the drive wheel engaged the forward friction disk as opposed to making contact with the reverse disk. When the drive lever is moved to the forward position (and left there) pressure between the drive wheel and the friction disk is maintained by a heavy spring. When you engage reverse, you hold it there manually, with as much pressure as you need. When I increased the length of travel to the forward disk, I DECREASED the amount of spring pressure holding the drive wheel to the friction disk; thus, it was still slipping. Simple fix? Shorten the spring. Now, for as long as the drive wheel lasts, I have rock solid drive.............
Has anyone had luck at buying a replacement drive wheel?
