Automower 420, 430X, 440, 450X, 520, 550, 550 EPOS front wheels repair and modification

This tutorial applies also to Automower 310, 315, 315X, but since spindle shaft’s diameter is smaller (6 mm), ball bearings, shield kit and shaft lock collar are different.
Automower 105, 305, 405X, 415X, 310 mark II, 315 mark II, 435X and 535X use different type front wheels.
Tools used:
T20 Torx screwdriver
Angle grinder
Rasper / file
Milling cutter 16 mm
Allen / Hex key
Torque screwdriver (accuracy at least one decimal place)
Parts used:
Ball bearing 688 (8 (ID) x 16 (OD) x 5 (Width) mm) with contact rubber seals (types: 688RS, 6882RS, 688RZ)
Slicone grease or grease, which is safe for plastics and rubber
Oil seal 12x18x3 mm
Stainless steel lock collar T8 (8 (ID) x 14 (OD) x 7 (Width) mm)
O-ring 80x5x90 mm
O-ring 2.5x1x4.5 mm

[@cdx873v]

Thanks allot for this tutorial! I need to check my mowers now, haha. I love these kind of videos!

[@jrioscouto]

Your automower videos are the best online! Not only you know how to fix them, you know how to improve the design. I wonder why husqvarna doesn't modify some parts for better life... suppose they just interested in selling parts. The front wheels are in my opinion the element that you are changing the most, alongside with the sliding plate and cutting disc. Let's see if they can endure 2 seasons with your mod!

[@ouherizon]

This design is still flawed, since outer bearing needs to sit inside a sleeve (originally there is no sleeve), otherwise wheel will slip on the shaft over time, bearings and inner plastic will diminish, which happens due to lack of axial pressure on the bearing (there will be a significant play, before this happens though). After installing a sleeve, axial pressure on the bearing is not needed at all (which is actually preferred to keep bearings from deteriorating), since sleeve keeps wheel from slipping and tilting towards the shaft. 19 mm milling cutter is needed for honing so sleeve could fit inside an outer plastic. At the moment I am testing sleeves, which are made of copper.

[@jrioscouto]

Thanks for the update! A video would be nice if that works. By the way, I've found an alluminium lock collar which is 6mm instead of 7 mm wide. Do you think i'll be able to avoid filing the pieces with it? Again, thank you for your work.

[@ouherizon]

@@jrioscouto I might do updated video about this matter, but only if this is tested properly. At the moment this sleeve mod is in testing phase. Yes, if 6 mm wide lock collar is installed, no filing is needed.

[@jaystheone1]

Oil seal 12x18x3 mm is just to replace the original one? So I can just purchase the Husqvarna one? Im having problem finding Oil 12x18x3 one also the 2.5x1x4.5 O ring is hard.

[@ouherizon]

Try aliexpress.com