These do not always hold their shape well in rough terrain. Currently, you have a wheel clutch issue that maybe made worse by the deck or pivot arm flexing. When this happens, you get an accelerated wear on the gear and shaft. A constant grind would indicate the trans is saying goodbye once again as you suspect.

The left axle is still rotating because it's a one-piece axle. tomplum is right; find out how to service the spur gear and internal ratchet at each rear wheel. It's easy and rewarding. The so-called 'transmission' isn't one - it serves the same function as the rear end in a RWD car - it changes the axis of rotation and provides a gear reduction. A further reduction is taken at the wheels, as well as another at the drive and driven pulleys. I think the current and previous problems are associated with the axle-end assemblies and drive wheel maintenance. If the drive wheels are not regularly cleaned and greased under severe use (like side-loading on hills), the steel bushing and axle bolt will suffer excessive wear which allows the wheel to tilt, possibly causing the gears to skip and grind. Just as a wild guess, I think I could fix it by servicing the axle ends and replacing the drive wheels and axle bolts. It may just need to be cleaned and greased.

I took the left wheel off and oiled the spur gear and checked the internal ratchet. Upon re-assembly I tightened the axle bolt as tight as I could. There is still a little more play in the left wheel than the right. At least it runs, but I have to further test it under side-loading. Also, I found the Toro service manual as a PDF file for the drive train in a Toro site. It includes the 20070 someplace. I wish they would have these manuals for the home operator specific to the model number and not all the others. Possibly a real DIY person could do all the drive train work themselves? The replies are a big help in pointing me towards what maintenance I need to do and that I don't have to dump the 20073 and get a commercial grade mower.

Sax a car rear end includes the differential which is not included in Toro type transmissions. (I know you probably know that)Anyway that is a common point of confusion with people because they fail to understand the way the wheel ratchets take the place of a differential by allowing one wheel or the other to rotate faster than the other one if needed like in a corner.
Richard904 I do not subscribe to the evaluation of Toro transmissions that customer service gave you. Something else is wrong. Perhaps an unusual defect or an excessive clearance problem. Toro transmissions would not routinely just fail because of some side loading or hills.

It's the wheels - the bushings/axles are worn out. Plus, the ratchets are gummy. He's doing the right thing, just needs to do more of it. If I'm reading it right, he got the LH wheel driving.

The 20073 (and 20017/18, 20041, 20047, etc) Toro rear wheel drive units are notorious for having the rear wheel hubs crack/break, having the pinion gears on the drive shaft ends wear out prematurely, and for having gear case failures. It all boils down to poor materials used in the manufacturing and poor design. This style of unit is very popular in my area, and I replace 15-20 of the 105-3036 wheels and 105-3040 pinion gears each per month (both in/out of warranty). Gear case assemblies are more sporadic, but the primary failure is the cheap input bearing, which then allows the input and mating gears to strip.

Moral of the story is - unload the mower, it is not suited for mowing anything except a flat yard, and even then, they don't last long.

The Toro Super Recyclers are MUCH better in their durability, and if you don't want one of those, buy a Honda.

Well, there you have it.

When I checked the left rear wheel there was a slight toe-in (front points in slightly) and there was run-out (wheel moves slightly in housing), but the right side was fine. This issue was buried in a previous posting on FWD vs. RWD. If the little spur gear is replaced and the wheel is replaced, then should some attempt be made to get the rear wheel support realigned to be more parallel to the long axis of the mower? If not, would this not further induce this problem aside from the poor quality of some of the parts?

Parenthetically, when I bought the 20073 a little over two years ago from Home Depot, I just thought the quality and serviceability would be equivalent to any new Toro out there. Consumer Reports never really talks about robustness, maintainability, or longevity; they do talk about quality of cut and ease of use.

My lawn tracter starts slowing down after it gets hot, like the transaxle is starting to fail. Someone said that you could remove the shock, and it would help. Can anyone tell me where the "shock" is located, and how to remove it?

The toe-in is very common to that machine, but isn't the cause of your problems. Toro actually came out with a pivot arm update kit for us service techs to install because there were some alignment issues, particularly in the 2005 model year units, however I have just as many units with the better aligned system come in with broken wheels and stripped gears.

The wheel hubs will break no matter how nicely aligned it is to the drive shaft simply because they are extremely weak, both in design and in material choice. The drive shaft gears wear out because they are made from very soft metal. Your front wheels are the same as the rear, just without the gear and the bushings in the hub. If you look closely at them, you might find that they are cracked as well.

As for the problems you are having now, call your local Toro authorized service shop and provide them your date of purchase. If it falls between April 1, 2007 and July 1, 2007, (if I recall the dates correctly) your unit should have a promotional extra year warranty (3 year total) through Toro. Have them fix it for you.

After you get it fixed, sell it and buy something more durable, because I promise you it will have the same problem again, especially knowing you are mowing decently steep inclines.

Having problems with my lawn tractor. the peerless transaxle model # 205-027b starts to slow way down after an hour or so of mowing. Sometimes seems it's going to stop. Any suggestions?

Yeah, try starting a new thread named "Peerless Transaxle Issues."

I've used Toro 22040's in my lawn care business for 15 ears. The trany/drive system is probably similiar if not identical to the commercial mowers. If they weren't problem free workhorses, I would not have kept making the same mistake for 15 years

Here are the secrets to the rear wheel miseries on Toros.

1. USE ONLY Marine Grade grease on the rear wheel height adjuster grease zerks. You will be amazed at how something so simple can make such a dramatic performance difference. I found out accidentally when I grabbed the grease gun for the outboard by mistake.

Causes of Rear Wheel Slippage.

1. The pinion gear is worn down. They are softer metal than the geared wheel rim. They are supposed to wear down because they are easier and cheaper to replace than the wheel rim itself. You probably don't have split rims which are on the commercials. Or, you allowed a worn pinion gear to grind to long on the geared wheel half and now both need to be replaced.

2. The drive shaft is slotted for a key. The key is rounded over OR you have been using the machine in muddy conditions and the slot is filled with mud, the spring under the key is broken or compressed with aforementioned mud and you haven't been giving the wheel a shot of grease after using it in the mud. The drive shaft is designed so that when grease is pumped into the zerk, the dirt and gunk is washed out of the keyway. Clean the keyway, buy a new spring and key reinstall and give it a few pumps of grease.

3. You been grinding away so long that the keyway on the drive shaft has been wallowed out and the key now sits sideways more or less and doesn't catch the pinion gear.

4. You disassembled the wheel, removed the pinion gear and reinstalled the pinion gear backwards. Yes, there is a right way and a wrong way for the pinion gear to go on.

5. The e-clip that holds the pinion gear in place is missing and has been chewed up by the pinion gear and geared wheel half.

6. And finally, from the symptoms you have provided either the roller bearing or needle bearing or both is shot. When ever you have excessive play either side to side or it looks like the rear wheel drops down when you lift the rear of the mower up, this is what you problem is. The rear wheel adjuster ran about 40.00 bucks the last time I checked but they are easily and cheaply rebuilt by punching the bearings out, taking them to a bearing shop and getting non Toro bagged bearings for under 8 bucks. You don't need a press to get them back in. Just a vice, small hammer and the old needle bearing to use a a seat to get the new one in. the roller bearing can just be hammered in with a piece of wood flush with the adjuster. You will also need a split ring pliers to remove the adjuster

After getting hot, the peerless tranaxle on my poulan garden tractor slows down to a crawl. Any sugestions on cause and cure?

You'll get a better answer over in the tractor forum.

I have exactly the same problem with my Toro 20041. Bought in October 2005. Left rear has no drive, right does, lots of grinding noise. It was fixed under warranty last year, but seems to have the same problem again after less than a year. Repair shop replaced wheels and pinion gear. Warranty is expired now. I also have a hilly lawn. The manual doesn't say it is unsuitable for hills or I never would have kept it! Thanks for all the info, I will take it apart as soon as I get a break from mowing. I usually can go 2 weeks between mowings in August but this year it is twice a week!
Bob B.

I know this discussion is a few years old now but have now struck similar problems twice. First happened when mower got to 18 months. On I got Toro dealer to fix - they replaced transmission. Told me I can't use it on hills if I want it to last because Toro build quality is average. Anyway, not sure why you would use a SP mower on anything but a hilly property. Anyway it seems to have gone again in just 6 months. Wish I had spent the extra and got the Honda.