Katahdin
Platinum Member
I replaced a broken axle on my 2006 Toro Z420 this week, it wasn't a bad job. I spread the work over three evenings.
Note that this job is actually an axle upgrade. You're removing the old 3/4 inch axle and replacing it with a one-inch thick one. The kits are on Amazon and Ebay for about $100, part number #115-5039. I am very impressed with the kit, it comes with the axle, bearings, new gear, clips, hub, and seals.
First night I dropped the transaxle, pressure washed it, and drained the fluid. Besides the bolts holding up the tranaxle and all the linkages, I disconnected the drive belt tensioner spring. I did not have to drop the electric clutch, once you have the bolts off you can move the transaxle towards the center of the mower and free it from the drive belt. I did not replace any belts as part of this repair.
I didn't think the oil looked too bad for a 9-year-old mower. The oil is 20W-50 motor oil.
Second night I took the transaxle housing apart and replace the axle, gear, bearings, clips, seals, and sealed it all back together with Ultra Black RTV.
The only special tools needed were snap ring-pliers, and one of the bearings I stuck in the freezer for about an hour to make it tap in easier with a dead blow hammer. It was also handy to have some tools to hook on and stretch the belt tensioner spring.
Finally, last night I filled the transaxle with new 20W-50 oil and installed it back into the mower, purged the air out of the system, and took the Z420 for a victory lap around the lawn.
The new hub and axle design is much stronger than the original. Note that hub nut gets torqued on at 240-260 ft-lbs.
This is the service manual best fits the model of transaxle and is very helpful guide when undertaking this repair. The kit also comes with a printed diagram on how the axle parts go together.
EZT (ZT-2100-2200)
Enjoy, I hope this post helps out my fellow Toro Z owners with broken 3/4 inch axles, :thumbsup: and there may be other makes and models that use this same Hydro-Gear transaxle.
Note that this job is actually an axle upgrade. You're removing the old 3/4 inch axle and replacing it with a one-inch thick one. The kits are on Amazon and Ebay for about $100, part number #115-5039. I am very impressed with the kit, it comes with the axle, bearings, new gear, clips, hub, and seals.
First night I dropped the transaxle, pressure washed it, and drained the fluid. Besides the bolts holding up the tranaxle and all the linkages, I disconnected the drive belt tensioner spring. I did not have to drop the electric clutch, once you have the bolts off you can move the transaxle towards the center of the mower and free it from the drive belt. I did not replace any belts as part of this repair.
I didn't think the oil looked too bad for a 9-year-old mower. The oil is 20W-50 motor oil.
Second night I took the transaxle housing apart and replace the axle, gear, bearings, clips, seals, and sealed it all back together with Ultra Black RTV.
The only special tools needed were snap ring-pliers, and one of the bearings I stuck in the freezer for about an hour to make it tap in easier with a dead blow hammer. It was also handy to have some tools to hook on and stretch the belt tensioner spring.
Finally, last night I filled the transaxle with new 20W-50 oil and installed it back into the mower, purged the air out of the system, and took the Z420 for a victory lap around the lawn.
The new hub and axle design is much stronger than the original. Note that hub nut gets torqued on at 240-260 ft-lbs.
This is the service manual best fits the model of transaxle and is very helpful guide when undertaking this repair. The kit also comes with a printed diagram on how the axle parts go together.
EZT (ZT-2100-2200)
Enjoy, I hope this post helps out my fellow Toro Z owners with broken 3/4 inch axles, :thumbsup: and there may be other makes and models that use this same Hydro-Gear transaxle.