I have a cub cadet model 1420 with hydrostatic drive that will not go forward or reverse. The drive belt is moving and the hydrostatic unit was replaced 3 years ago. I still have to engage the lever to push the mower. I had just mowed my yard and after washing the mower I started it up and moved 5 feet and stopped. Motor kept running but would not go either way.

If your 1986 Cub Cadet Hydro 1210 is experiencing difficulty moving forward but works fine in reverse even after changing the transmission filter and fluid, there could be a few potential reasons for this issue. Here are some steps you can take to troubleshoot the problem:
1. **Check Drive Belt:** The drive belt is responsible for transferring power from the engine to the transmission. A worn or damaged drive belt can affect forward movement. Inspect the drive belt for any signs of wear, fraying, or damage. If the belt is in poor condition, consider replacing it.
2. **Check Tension of Drive Belt:** Ensure that the drive belt is properly tensioned. A loose drive belt can lead to slipping and difficulty in forward movement. Adjust the tension according to the manufacturer's specifications.
3. **Inspect Linkage and Connections:** Examine the linkage and connections between the control lever, transmission, and the drive system. Loose or misaligned linkage can result in improper engagement of gears, affecting forward movement.
4. **Hydrostatic Transmission Issues:** Since your Cub Cadet Hydro 1210 uses a hydrostatic transmission, there could be issues with the hydrostatic unit itself. Check for any signs of leaks, damaged hoses, or worn components in the hydrostatic transmission system.
5. **Transmission Oil Level and Quality:** Ensure that the transmission oil level is correct and that you're using the recommended type of oil. Poor-quality or incorrect transmission oil can lead to performance issues.
6. **Air in the Hydraulic System:** If there's air trapped in the hydraulic system, it can cause issues with the hydrostatic transmission. Bleed the hydraulic system to remove any air bubbles.
7. **Transmission Pulley and Sheaves:** Check the transmission pulley and sheaves for wear or damage. If these components are not functioning properly, they can affect the movement of the drive belt.
8. **Check for Obstructions:** Inspect the underside of the mower deck and the drive system for any debris, obstructions, or objects that might be interfering with the forward movement.
9. **Professional Inspection:** If none of the above steps resolve the issue, it might be a more complex problem requiring the expertise of a professional technician. They can perform a more in-depth diagnosis of the hydrostatic transmission system and identify any underlying issues.
Keep in mind that working with mechanical and hydraulic systems requires knowledge and expertise. If you're not comfortable performing these checks and repairs yourself, it's recommended to consult a qualified technician who has experience with Cub Cadet or similar equipment.

You don't by size, you buy by make and model.

https://www.google.com/search?q=cub+cadet+1450+hydrostatic+replacement+belts

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https://www.cubcadet.com/wcsstore/CubCadetCatalogAssetStore/Attachment/owners%20manuals/residential/LTX1045_769-04349.pdf

First check hydrostat bypass, see page 9 from above link. Transmission is sealed so there's no simple way to check fluid level and if you don't suspect it has leaked there little reason to check. If hydro-bypass is off, then the most likely cause is the traction drive belt. See parts diagram.


https://www.partstree.com/parts/cub-cadet/mowers-lawn-garden-tractor/ltx1045-13wx91at056-13wx91at010-cub-cadet-lawn-tractor-2011/drive-system/


Applying brake causes drive belt to go slack, while releasing brake puts tension on the drive belt. So likely the belt has broken, or brake linkage moved out of place, or belt is so worn it no longer turns the transmission drive wheel.

Assume it's a hydrostatic transmission - most probably the drive belt has come off or broken. Be sure to replace it with a Kevlar belt as changing the belt isn't easy and you don't want to have to repeat the process too soon.

Which model cub? Hydrostatic??

If this is a hydrostatic transmission, one of 3 things:
1. Drive belt off pulleys (recommend replace belt if so)
2. Belt broken (obviously, replace)
3. Hydrostatic transmission failed (least likely, but this is an expensive repair shop issue if so)


This happened to my GT1554 two weeks ago - fortunately, replacing the belt resolve the problem.

CK TO SEE IF THE BYPASS LEVER IS STIKING IT MY NEED TO BE FREED UP

check the drive belt for ware could be slipping or might need to add oil to rearend

you didnt say what model this is, but i assume its hydrostatic because it has a drive shaft. is the hydrostatic unit filled with oil¿ if its ok, check the linkage from the pedal to the rearend (hydrostatic drive) make sure its not broken or loose.. if that l@@ks ok, check both ends of the drive shaft making sure the couplers are not broke and the drive shaft is ok. hope this helps.