Mastering Your MF135 Multipower Transmission Oil Change

Owning a classic Massey Ferguson MF135, especially one equipped with the legendary Multipower transmission, is a truly rewarding experience. These robust tractors are workhorses, built to last, but even the toughest machines require diligent care to perform at their best. One of the most critical maintenance tasks for an MF135 with Multipower is a regular transmission oil change. If you've noticed your hydraulics acting sluggish, jerking, or failing to lift heavy loads, or if your Multipower system isn't engaging as it should, there's a good chance your transmission oil is past its prime. Often, a visual inspection reveals oil that resembles 'milky coffee' – a clear sign that water ingress and contamination are compromising your system's efficiency and longevity. This guide will walk you through the process, including locating and cleaning the often-overlooked Multipower filter, ensuring your tractor runs as smoothly as it did when it rolled off the production line.

Safety First: Preparing for the Task Ahead

Before you even think about reaching for a spanner, safety must be your absolute priority. Working underneath a tractor can be incredibly dangerous if proper precautions aren't taken. Ensure your Massey Ferguson MF135 is on level ground. While slightly lowering the left side can aid oil draining, make sure it remains stable and secure. Engage neutral in the gearbox and the high/low range selector. Crucially, apply and lock the brakes fully, then secure the wheels with sturdy chocks both front and back. Remember, you'll be spending time underneath the tractor, so take every measure to prevent any unexpected movement. Finally, ensure the PTO selector is firmly in Neutral. This seemingly small step is vital for safe operation and subsequent reassembly.

Gathering Your Tools and Materials

To make this job as smooth as possible, it's wise to have all your necessary tools and materials laid out before you begin. Preparation saves time and prevents frustrating interruptions. Here's a list of what you'll need:

• Two large oil drain containers (one with ~30-litre capacity, one with ~20-litre capacity)
• Socket set and spanners (for drain plugs, PTO cover bolts, mudguard, footboard)
• Wire cutters
• New locking wire (essential for the main hydraulic filter)
• Degreaser spray
• Clean rags and cloths
• Air gun (optional, for filter cleaning)
• New transmission oil (approximately 31 litres, meeting MF1129A specification or better)
• Funnel
• Flashlight or head torch (for inspecting internal components)
• Wheel chocks
• Safety glasses and gloves

Draining the Old Oil and Preparing for Access

With your tractor safely secured, you can begin the process of draining the contaminated transmission oil. First, lower the hydraulics completely. This ensures that all hydraulic fluid is returned to the reservoir and will drain out with the rest of the transmission oil. Next, you'll need to remove some external components to gain access to the drain plugs and internal filters. Carefully remove the left-hand mudguard (fender), the left footboard (note that its rear mount is often bolted through the PTO cover plate), and if fitted, the handbrake rod. Keep all bolts and components organised, perhaps in separate containers, to ensure a smooth reassembly.

Now, position your two large drain containers beneath the tractor. You'll find two primary drain plugs for the transmission system. The first is located at the rear, just below the PTO selector. The second is situated just in front of the front footboard mount. Carefully loosen and remove both plugs. Be prepared for a significant volume of oil – the rear plug typically drains around 30 litres, while the front plug accounts for approximately 20 litres. Allow ample time for all the old, contaminated oil to drain completely. The milky, coffee-like appearance of this old oil will likely confirm your suspicions about its condition.

Table: Transmission Oil Drain Capacities

Accessing and Cleaning the Filters: The Hydraulic Pump and the Elusive Multipower Screen

Once the oil has fully drained, it’s time to tackle the filters. This is where attention to detail pays off. Start by removing the PTO cover. This usually comes off as one piece with its selector arm. As you remove it, take careful note of the selector arm's position and the groove it mates with inside the gearbox. This observation is critical for correct reinstallation, as failing to align it properly will result in a non-functional PTO selector.

The Main Hydraulic Pump Filter

With the PTO cover removed, locating the main hydraulic pump filter should be straightforward. It sits just in front of and slightly below the PTO cover opening. You'll immediately notice that this filter is secured with a thin locking wire, running from the top of the filter to a small hole. This wire serves a vital purpose: preventing the filter from undoing itself and potentially causing catastrophic damage to your gearbox. Carefully cut this wire, ensuring no small pieces drop into the gearbox. Then, unscrew and remove the filter. Be gentle, as it's often made of three parts and can come apart if not handled with care.

Thoroughly clean the filter. These filters are typically reusable unless visibly damaged. Use a good quality degreaser spray and, if available, an air gun to dislodge all accumulated sludge and debris. Inspect it for any tears or damage; if compromised, replace it with a new one. Set the clean filter aside for reinstallation later.

Unveiling the Multipower Filter Screen

Now for the part that often puzzles MF135 owners: the Multipower filter. The genuine service manual and online resources often provide little to no information about its location. However, it is there, and it's crucial for the proper functioning of your Multipower system. Just behind the main hydraulic pump filter, you'll find a small rectangular screen – this is your Multipower filter. It's typically hidden behind a half-circular baffle. (Note: Later MF135 models might have an external filter, and this internal screen may not be present). The original author found his covered in crud, which is a common finding and a major contributor to poor Multipower performance.

To access it, gently bend one side of the half-circular baffle to expose the screen. Once exposed, clean it thoroughly using a spray degreaser and a clean rag. A long-nozzle spray can (like from a bug spray can) can be very effective for directing pressure and degreaser precisely onto the screen. Once one side is clean, carefully bend the baffle back into position and then gently bend the other side to expose the remainder of the Multipower screen. Clean this side equally thoroughly. After cleaning both sides, carefully reform the baffle back to its original shape. This step is often overlooked but is absolutely essential for restoring your Multipower system.

Final Cleaning and Reassembly

With both filters cleaned, take a clean cloth and some degreaser and give the bottom of the gearbox a good wipe out. Remove any remaining sludge or debris that might have settled. If the inside of your gearbox is exceptionally cruddy, you might consider an optional flushing procedure. This involves adding about 15-20 litres of diesel or a suitable flushing degreaser into the gearbox, driving the tractor slowly for a few minutes (with minimal load), and then thoroughly draining it again. This can help dislodge stubborn deposits, but ensure every trace of the flushing agent is drained before adding new oil.

Now, begin reassembly. Reinstall the main hydraulic pump filter. It only needs to be finger-tight, but here's the critical part: you must reinstall a new locking wire. Do not forget this step, as it prevents the filter from vibrating loose and causing severe internal damage. Secure the wire firmly.

Next, carefully reinstall the PTO cover. This is where your earlier observation of the selector arm's position becomes vital. Ensure the selector arm correctly engages with its selector track inside the gearbox. If it doesn't, your PTO selector will not work. Double-check its movement and engagement before tightening the cover bolts.

Finally, clean both drain plugs thoroughly and reinstall them, ensuring they are tightened to the manufacturer's specifications to prevent leaks. Reinstall the footboards, handbrake rod, and fender that you removed earlier.

Refilling with Fresh Oil and Final Checks

With everything reassembled, it's time to introduce the lifeblood of your transmission system: fresh, clean oil. The filler hole is conveniently located next to the gear selector. For an MF135, the transmission system typically requires around 31 litres of oil to reach the maximum level on the dipstick. However, it's always best to fill cautiously to avoid overfilling.

A good approach is to add approximately 20 litres in one go. After this, add the remaining oil one litre at a time, checking the dipstick after each addition. This methodical approach ensures you reach the correct level without exceeding it. The type of oil is paramount: you must use oil that meets the Massey Ferguson MF1129A specification or better. The original author used Hydralink Farmlube 15/40, which is a suitable choice, but any oil meeting or exceeding the MF1129A spec will suffice. Using the correct specification oil is crucial for the proper operation and longevity of your hydraulic and Multipower systems.

The Transformative Results

The immediate difference after performing this comprehensive transmission oil change can be truly astonishing. The original author reported their Multipower system now working great, hydraulics operating much faster, no more jerking, and the ability to lift almost anything. It's a testament to the fact that clean, fresh oil can dramatically improve the performance and responsiveness of your classic MF135. This job, while taking around four hours for a first-timer, is an incredibly worthwhile investment in your tractor's health and capability.

Frequently Asked Questions (FAQs)

Q1: How do I know if my MF135's transmission oil needs changing?

Common signs include sluggish, slow, or jerky hydraulics, the hydraulics struggling to lift heavy loads or dropping when the PTO is off, and the Multipower system not engaging correctly. A visual inspection of the oil on the dipstick revealing a 'milky coffee' appearance is a definitive sign of water contamination and indicates an urgent need for an oil change.

Q2: What type of oil should I use for my MF135 Multipower transmission?

You must use an oil that meets the Massey Ferguson MF1129A specification or a superior equivalent. This specification ensures the oil has the correct properties for both the hydraulic system and the wet clutches within the Multipower transmission. Do not use standard engine oil, as it lacks the necessary friction modifiers and hydraulic properties.

Q3: How much transmission oil does an MF135 with Multipower take?

The entire transmission and hydraulic system of an MF135 with Multipower typically requires approximately 31 litres of new oil to reach the 'Max' level on the dipstick after a full drain. It's advisable to add in stages and check the dipstick frequently to avoid overfilling.

Q4: Why is the Multipower filter so hard to find information about?

Many genuine service manuals and online resources often omit detailed information about the internal Multipower screen. This is likely due to its somewhat hidden location behind a baffle and the fact that later models might have transitioned to external, more easily accessible filters. However, as demonstrated, it is a crucial component that requires cleaning during the oil change process for optimal Multipower performance.

Q5: Is it really necessary to replace the locking wire on the main hydraulic pump filter?

Yes, absolutely. The locking wire prevents the filter from unscrewing itself due to vibrations during operation. If the filter comes loose, it can disintegrate, sending debris throughout the transmission and hydraulic system, leading to severe and costly damage to your gearbox and pump. Always replace it with a new locking wire.

Q6: Can I flush the transmission system with diesel if it's very dirty?

Yes, an optional flush with 15-20 litres of diesel or a dedicated degreaser can be beneficial if the gearbox interior is exceptionally cruddy. Drive the tractor slowly for a few minutes to circulate the flushing agent, then drain thoroughly. Ensure all traces of the flushing agent are completely removed before refilling with fresh transmission oil, as residual diesel can dilute and compromise the properties of the new oil.

Q7: My hydraulics are still a bit slow after the oil change. What could be wrong?

While an oil change significantly improves hydraulic performance, persistent sluggishness could indicate other issues. These might include a worn hydraulic pump, sticky relief valves, internal leaks within the hydraulic system, or even issues with the hydraulic lift cylinder seals. If symptoms persist, further investigation by a qualified mechanic may be necessary.

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