Toro 20339
Wheels and drive gears for the Toro 20339
Short answer
Front drive gear 59502 in both ranges we opened. Rear high wheel 137-4837P appears only in the later one, 400000000–401999999.
Verified options
What we have verified
| Part | Serial range | Status |
|---|---|---|
| 59502Replacement Front Wheel Drive Internal Gear | All | Confirmed fit |
| 137-4837PReplacement 11 in. Rear High Wheel for Push and Front Wheel Drive Lawn Mowers | 400000000–401999999 | Confirmed fit |
| 137-4837PReplacement 11 in. Rear High Wheel for Push and Front Wheel Drive Lawn Mowers | 316000001–316999999 | Not verified |
What decides it
The numbers that matter here
- Front, both ranges
Drive gear 59502
Toro’s name calls it an internal gear and its description calls it an 8-in. wheel assembly. We quote both rather than deciding which one arrives.
- Rear, later range only
137-4837P, Replacement 11 in. Rear High Wheel for Push and Front Wheel Drive Lawn Mowers, in 400000000–401999999
It does not appear on the 316-series listing we opened. We record that as unknown rather than as a statement that it does not fit.
- Do not read across from the 20334
59502 is still listed here where that machine drops it
Two machines, one part number, different behaviour. The other model’s page will mislead you.
In detail
Choosing wheels and drive gears for this mower
Two wheel parts, and they behave differently across the two listings we opened.
Toro lists 59502, the Replacement Front Wheel Drive Internal Gear, for the 20339 in both ranges. It lists 137-4837P, which Toro names the Replacement 11 in. Rear High Wheel for Push and Front Wheel Drive Lawn Mowers, only in 400000000–401999999 — it does not appear in the 316-series listing we opened.
The front gear is worth a second look for a different reason. On the 20334, Toro stops listing 59502 in that machine's 400-series range and shows a front wheel instead. Here it is still listed. Same part number, two machines, and it stays on one where it leaves the other. Toro does not say why, and neither do we — but it does mean you cannot read the 20334's page and apply it here.
The rear wheel's name is also worth reading carefully. Toro describes 137-4837P as designed for push and front-wheel-drive mowers. That is a statement about intent, not an exclusion, and we record no incompatibility because Toro states none.
We opened two of the nine ranges Toro publishes for this model.
The mistake we see most
Method
How we established this
We recorded the wheel parts shown on Toro’s parts listings for model 20339 under both ranges we opened, and compared 59502 against the 20334 listing where that part stops appearing.
Same machine
Other parts we have verified for the Toro 20339
Other machines
Wheels and drive gears on the other mowers we cover
The answer is not the same on every machine, which is the point of checking rather than assuming.
Provenance
Sources
Last verified against these sources on August 18, 2026.
- 1
The Toro Company · Primary source · Accessed August 17, 2026
Lists 20234 (Engine Maintenance Kit for Briggs & Stratton Engine), 38990 (22 Inch Drive Belt for Recycler Mower), 59534P, 59502 and 490-2012. The range selector names eight further serial ranges for this model number.
- 2
The Toro Company · Primary source · Accessed August 17, 2026
Lists 130-8148 in place of 20234, and adds 137-4837P (Replacement 11 in. Rear High Wheel). Still lists 38990 and 59502.
- 3
Parts — 22" Personal Pace Electric Start Mower, model 20334, serial range 400000000–401999999
The Toro Company · Primary source · Accessed August 17, 2026
The later range. Still lists 130-8148 and 131-4590, so the maintenance kit does not change again here. It lists 137-4833P (8 Inch Front Wheel) and does not list 59502 — a second, separate boundary within the same model number.