RM11000 Rovic Mulcher Blade Carrier Nut Locking Mechanism Installation Guide

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

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