The John Deere GX20072 belt, which replaced GY20570, is the 42 inch mower deck belt: Deere lists it at 2635 mm (103.7 in) effective length, 12.7 mm (1/2 in) wide and 8.89 mm thick. Our replacement belt for GX20072 / GY20570 is listed at 13 mm wide and 2635 mm (103.75 in) outside, made with Kevlar.
If that's your number, you can stop here. The 48 inch deck belt (GX21833, Toro 119-8820) is further down.
| John Deere GX20072 (genuine) | Our pn165 (non-genuine) | |
|---|---|---|
| Replaces | GY20570 | GX20072 and GY20570 (John Deere and Sabre) |
| Deere's name | Mower Drive Flat Belt | Belt, V-belt type |
| Length | 2635 mm (103.7 in) effective | 2635 mm (103.75 in) outside |
| Width | 12.7 mm | 13 mm (1/2 in) |
| Thickness | 8.89 mm | not stated |
| Cord | not stated | Made with Kevlar |
| Deck | 42 inch | 42 inch |
Source: shop.deere.com GX20072 and GY20570 pages, and the John Deere D105 42 inch deck Replacement Parts Guide, read 28 September 2026; our product data for pn165.
GX20072 belt size: match the millimetres, not an A number
Deere quotes GX20072 by its effective length. Our listing quotes the outside length. On this belt they're the same figure, 2635 mm, so the two match without any conversion.
That matters because A-section belts are numbered by inside length, and 2635 mm outside doesn't land neatly on one A number. Comparing another belt? Compare outside or effective length in millimetres. Our guide to 1/2 inch mower belt sizes explains inside, outside and effective lengths.
Deere calls GX20072 a "flat belt", but it titles GY20570 a "V-Belt", and 12.7 x 8.89 mm is close to the 13 x 8 mm of a standard 1/2 inch V-belt. Our pn165 is a V-belt.
Which John Deere mowers use GX20072?
Deere's parts site lists GX20072 for these models: 102, 105, 108, 115, 125, 135, 1442, 1642HS, 1742HS, 1742PR, D100, D105, D110, D120, D125, D130, E100, E110, E120, E130, L17.542, L100, L105, L107, L108, L110, L111, L118, L130, L1742, LA100, LA105, LA110, LA115, LA120, LA125, LA135, S100, S110, S120, X105, X106, X107, X110, X120, X125, X126, X127 and X145.
Our pn165 listing also names the Sabre 42 inch 14.542GS, 17.542HS, 1642HS and 1742HS. Check the belt number in your operator's manual first: some models take a different belt with a different deck.
The 48 inch deck belt: GX21833, GX20571 and Toro 119-8820
Deere lists GX21833 as the 48 inch deck belt at 3599.4 mm (141.7 in) effective length, 14.2 mm wide and 11.4 mm thick. Its guides show it on the D140 with a 48 inch deck and the Z255 EZtrak, and shop.deere.com adds models including the 145, 155C, D150, D160, E140, E150, E160, E170, L120, L130, LA130 to LA165, S140, S160, S170 and X140.
Our replacement for GX20571 / GX21833 and Toro 119-8820 is listed at 12.7 mm (1/2 in) wide, 139 in (3530.6 mm) inside and 141 in (3581.4 mm) outside, made with Kevlar. That's narrower and 18 mm shorter than Deere's genuine belt. On the L120 and L130, our listing covers only some serial ranges, so check your manual.
The same belt replaces Toro 119-8820, which Toro sells as its "50 Inch Deck Belt for TimeCutter Mower". Don't confuse it with Toro 119-8819: our listing gives that one as the 42 inch TimeCutter deck belt, 111 in inside and 113 in outside.
Which Bearings Express belt fits
- Pick the GX20072 / GY20570 replacement belt (pn165) for a John Deere or Sabre 42 inch deck that takes GX20072 or GY20570.
- Pick the GX20571 / GX21833 / Toro 119-8820 belt (pn431) for a John Deere 48 inch deck or a Toro TimeCutter 50 inch deck that takes one of those numbers. It's narrower and 18 mm shorter than Deere's genuine GX21833, so check your manual first.
- Pick the Toro 119-8819 belt (pn501) for a Toro TimeCutter with a 42 inch deck.
Other John Deere belts we carry are in the John Deere collection.
Questions people also ask
What is the GX20072 belt cross reference?
GY20570 is the older Deere number it replaced, and Sabre used the same two numbers on its 42 inch mowers. Our aftermarket match is pn165.
What is the GY20570 belt length?
GY20570 was replaced by GX20072, which Deere lists at 2635 mm (103.7 in) effective length. Our replacement is 2635 mm (103.75 in) outside.
What is the GX21833 belt length?
Deere lists GX21833 at 3599.4 mm (141.7 in) effective length. Our pn431 replacement is listed at 141 in (3581.4 mm) outside.
Is A-GX20072 the same belt?
Yes. shop.deere.com lists A-GX20072 under the same name, "Mower Drive Flat Belt, Effective Length 2635 mm (103.7 inch)".
Related reading
- Mower belt listed as "1/2 x 95"? How to turn it into an A or AK belt size
- Mower belt buyer's guide
- Do I need a Kevlar mower belt?
Sources
- John Deere, shop.deere.com: GX20072 "Mower Drive Flat Belt, Effective Length 2635 mm (103.7 inch)", GY20570 "V-Belt", A-GX20072, and GX21833 "Mower Deck Drive Flat Belt, 3599.4 mm (141.7 inch)", read 28 September 2026.
- John Deere Replacement Parts Guides on deere.com: D105 with 42 Inch Side Discharge Deck; D140 with 48 inch Deck; Z255 EZtrak Mower, read 28 September 2026.
- Toro, toro.com product pages 119-8820 and 119-8819, read 28 September 2026.
- Gates Australia, Industrial Power Transmission South Pacific Catalogue (2018), printed p. 29 and the A-section length table, p. 31, read 27 and 28 September 2026.
Checked against John Deere's and Toro's own parts pages, Deere's replacement parts guides and Bearings Express product data on 28 September 2026.
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