RM11000 Rovic Mulcher Blade Carrier Nut Locking Mechanism Installation Guide
- June 13, 2024
- Rovic
Table of Contents
RM11000 Rovic Mulcher Blade Carrier Nut Locking Mechanism Installation
Guide
Prerequisite Technical Bulletin
MU-TB-0001 (if applicable)
Brief Description
Add a nut locking mechanism, to secure the central castle nut, at interface between gearbox output shaft and blade carrier – Thus increasing the vibration tolerance of the interface
Affected Models
1.8m Mohorovicic Mulches using the AFTGBG130_1.146/MU0081 (Bearing Man) gearbox, namely:
- MU180-0001 – MU180S – 1.8m Side Mulches
- MU180E-0001 – MU180R – 1.8m Rear Mulch
Affected Build Date
Inception – December 2021
Problem Area Reference Image
Relevant Kit/Parts
Per Mulches
- MU0227 (x1)
- Locate Thread locker (Medium Strength [Blue]
Kit/Parts Image
Castle nut shown for clarity and not included (c/w gearbox)
Approx. Fitment Time
1-2 hours
Complexity
2/5
Tooling Required
- Large breaker/power bar
- 50mm heavy duty socket
- M10x1.5 thread tap (ISO Coarse)
- Tapping drill bit for M10x1.5 (8.50mm recommended)
- Large sledge hammer
- Large wooden block
- 8mm Allen head bit (For M10 Allen cap screw)
- Small grinder with slim cutting disc installed
- Torque wrench (73 Nm capable)
- Sharp-nosed plier
- An overhead crane would be beneficial
- Requisite PPE Instruction
- Ensure that the machine is completely detached from tractor for safety
- Orient the mulcher upside down (blade carrier facing upward)
- Ensure that the machine is well supported and it is stable enough to be worked on
Step 0.0 – Verify Gearbox
Ensure that the gearbox fitted is the latest generation Bearing Man unit – to check this, measure the diameter of the threaded shaft where the castle nut is fastened
If ø = 32mm –> Implies that the gearbox is either from Prodist or is an old Bearing Man unit. Refer to MU-TB-0001.
If ø = 35mm –> Implies that the gearbox is the correct Bearing Man unit, and one can proceed.
Step 0.1 – Check condition of interface
Check that the blade carrier is securely attached to the gearbox output shaft. There should be no relative play between the output shaft and the blade carrier. The castle nut should also be secure. If this is not the case, then the output shaft of the gearbox may already be compromised and require replacement. Output Shaft – AFTGBG130-1; Castle Nut – AFTGBG130-22
Instruction
Step 1 – Loosencastle bunt
Should Step 0, above, pass scrutiny – use the sharp-nosed plier to remove the split pin which interlocks the castle nut to the gearbox output shaft. Then, use the breaker bar with 50mm socket to loosen, and then subsequently remove, the castle nut.
Step 2 – Add serration to castle nut and washer
Use the grinder (with slim cutting disk) to add fine serrations to the underside of the castle nut as well as both sides of the washer (MU0228 – found within MU0227). Serrations should be numerous and radially oriented. Do not cut too deep.
Step 3 – Install washer and castle nut
Place the now-serrated washer in place and thread the (also serrated) castle nut over top. Use the breaker bar and socket to torque the nut down tightly
With the wooden block placed over the center of the blade carrier, use the sledge hammer to impact the wooden block and thus force the blade carrier onto the gearbox’s splines output shaft.
Repeat a torque > impact > torque sequence until the castle nut no longer rotates under significant force application to the breaker bar and the blade carrier is no longer “settling” down further onto the gearbox output shaft splines. Fastening torque of the castle nut is in the order of 2000 NM for reference.
Step 4 – Install locking mechanism
Now that the blade carrier and castle nut are in their final positions – insert the welded nut locking assembly such that it slips over, and engages with, the castle nut. This has occurred when the plate section meets the blade carrier itself.
Use the plate as a template and mark out 4 opposing holes. The chosen holes
should be as near to the existing bolt heads as possible, as this offers an
additional layer of protection against impacts – see below image.
Remove the welded assembly and drill and tap these 4 locations in the blade carrier to a depth of approximately 13mm.
Reinstall the welded assembly in the same orientation as before (when using as a template).
Apply Loctite to, and torque down, the Allen cap screws (73 Nm).
Cape Town
Tel: +27 (0)21 907 1700
Fax: +27 (0)21 907 1760
Email: admin@rovicleers.co.za
Johannesburg
Tel: +27 (0)11 396 6200
Fax: +27 (0)11 396 6220
Email: infojhb@rovicleers.co.za
Pietermaritzburg
Tel: +27 (0)33 346 2727
Fax: +27 (0)33 346 2746
Email: infopmb@rovicleers.co.za
