Never a good time for the mower self drive to quit, my yard is hilly and I just can’t imagine pushing my Honda for an hour and a half.
So can you push a self propelled lawn mower? You can push a self propelled lawn mower, it won’t damage the transmission in any way. However, it may be difficult to do so, self propelled mowers are a little heavier than a regular push mower.
In this guide I will help you diagnose why your mower won’t drive, if you can fix now, or if you need to take to a shop.
Sure you can push it, but lets first see if we can fix it. Pushing a self propelled mower is though work, especially on a hot day.
Self propelled mowers are built more robustly than a regular push mower, obviously being self propelled the weight of the mower is less important. They use stronger materials and pack them with extra features.
It’s no surprise that regular push mowers are built like a desert when it comes to extra features. If you need video help, check out “Common self drive faults video”, it walks you through self drive common faults and how to fix them.
How Does A Self Propelled Lawn Mower Work?
Self propelled systems are pretty simple really, of course the more expensive higher spec mowers may be fitted with more sophisticated Hydro-static drive system. (More on Hydro-static later). Lets begin with a brief out line of how a basic lawn mower self drive system works. This may seem unnecessary but I think it will help you diagnose and fix your fault more quickly and accurately.
For a drive system to be effective it must have a power source, it must have an assembly that converts engine torque into propulsion and to make it really useful it must be controllable.
Trans-axle and belt setup
The engine supplies the power for the drive system. The power is transferred from the engine to the trans-axle using pulleys and a drive belt. The pulley’s and belts are crucial to the whole operation, any slip here and available power is lost. More on belts and pulley’s later.
If the engine runs poorly, your drive system will feel sluggish and slow, but if the engine runs, your drive will still work. A mower should be serviced once a year, check out “Mower engine tune-up” (internal link).
Engine to Trans-axle – Trans-axle driven by belt which is driven by the engine pulley.
This is a fancy word for a transmission and an axle that is combined into one assembly. Basically, without getting too far into the deep end, it’s what makes your mower move. I wrote a complete explanation of trans-axle here (Internal link). The power from the engine is transferred to the trans-axle and it in turn sends the power to each of the powered wheels but only when the operator applies the drive lever.
Trans-axle – Trans-axle is the business end of moving your mower.
To make all this power at the wheels work, you need to be able to turn it off and on, otherwise it’s useless. A bail lever is used to apply the drive to the wheels on most mowers. A bail lever is also known as the dead mans lever, basically means if your hand slips from the lever the mower will stop moving.
The same type lever is also used on most mower starting systems. The bail lever is connected to the trans-axle control lever, using a braided cable inside a shielded plastic outer, same as a bicycle brake cable. If your bail lever lacks tension, it’s a good indication the cable has broken, detached or needs adjustment. it’s all covered in this article.
Drive Control – Most mowers use a bail lever.
Drive Belts & Pulley’s
Drive Belt – Most important that the belt is in good condition and is the right size.
Drive belts are the most likely reason a self drive system isn’t working. The belt as you know transfers the power from the engine pulley, (located just above the blade) to the trans-axle. A faulty or worn belts may cause no drive, slow drive, throwing the belt, noise and smoke. A belt can often cause other damage as it’s thrown, it can wrap around other components.
Belt fault are most common root cause of self drive issues.
A belt that’s too long or worn, can be a real pain. Often it’ll work fine when cold but as the belt heats up, it can slip. The only fix here is to fit the correct belt. Pulley’s are equally important, but give less trouble, commonly made from metal or plastic, you know which one lasts longer.
Self Propelled Lawn Mower Wheels Won’t Turn?
Now we’ll ge to the business end of this post – finding and fixing your self drive fault. Most mowers are rear wheel drive, that means the power goes to the rear wheels. But some mowers like Craftsman are front, and some higher spec models are four wheel drive. The first job, know which wheels do the driving.
To check, we’ll need to tilt mower over. But before we can do that, we’ll need to remove the spark plug and turn the gas valve off if fitted. You can read more about tilting your mower correctly here. Or check out the video here.
Turn Mower Over – Now we’re ready to turn mower over, remembering to tilt it air filter side up.
Check – Check where the trans-axle is located, most will be rear drive.
Test 1 – Stat the mower and with drive engaged lift the driving wheels off the ground.
Two outcomes are possible:
1 – The wheels turn, even slowly – indicates the drive system itself is likely OK. It may just need drive cable adjustment. I wrote a post on adjusting a drive cable here (Internal link). Or you’ll find the subject covered in the “Self drive troubleshooting video” here.
2 – The wheels still don’t move, we’ll have to go deeper, see test 2.
With all wheels on the ground again and the the mower engine off.
Test 2 – Apply the drive lever, and pull the mower back ways.
Two out comes are possible:
1 – The driven wheels (usually rear) lock up – indicates your drive cable is in place. However it could still need adjustment, so check out adjusting a drive cable post here (internal link). It could also indicate a problem with the drive belt. (see below)
2 – The rear wheels don’t lock up – likely indicates the drive cable is out of adjustment, detached or broken. The mower will need to be disabled, turned over and the cable inspected.
Test 3 Check Belt – Check the belt is on both pulley’s…
…and that the drive control cable is connected at transmission.
- If you find the drive cable is detached, then it is likely broken and will need replacing. Covered here in “Fix self drive cable”.
- If after inspection you find a drive belt issue, common problems include – loose, broken, worn or jumped off. The solution to all of these problems is replace the belt, it’s all covered in the “Self drive troubleshooting video” here.
- If on inspection you find both belt and drive cable in place, the problem may lie with the axle pins, drive gear, wheels or the axle may have failed. Testing and repairing axle pins, gears and wheels are all covered in the “Self drive troubleshooting video” here.
Can you pull a lawn mower backwards? You can pull a mower backwards, but the quality of cut will be poor. If your mower drive cable is over adjusted, the mower won’t pull backwards. Release drive cable tension by turning the adjuster until the mower will pull backwards.