Front gearbox <em>Nissan Murano Z51</em>: how it works, why it breaks and how to fix it

Nissan Murano Z51 - a crossover with all-wheel drive, where the front gearbox plays a key role in transmitting torque to the front wheels. This unit operates under high load conditions, especially when used off-road or with a trailer. Unlike rear-wheel drive models Nissan, where the rear axle gearbox takes on the main load, in Murano Z51 The front gearbox is integrated into the gearbox and requires special attention.

Owners often encounter hum, vibration or oil leaks from this unit, but do not always understand that the problem lies here. In this article, we will analyze the structure of the front gearbox, typical faults, diagnostic methods and repair nuances - from replacing oil seals to a complete overhaul. We will also give recommendations on the selection of spare parts and oil to extend the life of the unit.

Front gear unit Nissan Murano Z51: diagram and principle of operation

Front gearbox Murano Z51 (body Z51, 2015–2021) is structurally integrated with the transfer case and front differential. It consists of:

• 🔧 Main gear (hypoid pair of gears) - transmits torque from the driveshaft to the differential.
• 🛠️ Differential — distributes force between the left and right wheels, allowing them to rotate at different speeds.
• 🔄 Bearings — support shafts and gears, reducing friction.
• 🛢️ Oil seals and seals - Prevent oil leaks.

Feature Murano Z51 - use hypoid transmission (offset gear axis), which reduces noise, but requires special oil GL-5 75W-90. The gearbox works in tandem with CVT Jatco JF011E, therefore the load on it is higher than in models with a classic “automatic”.

Unlike Nissan X-Trail T32, where the gearbox is located separately, in Murano Z51 it is integrated into the gearbox housing. This complicates repairs, but makes the structure more compact. Important: when disassembling the gearbox, be sure to check the condition differential pinions — their wear leads to play and hum.

Signs of a front gearbox failure: when to sound the alarm

Front gearbox Murano Z51 rarely fails suddenly - problems usually accumulate gradually. Pay attention to the following symptoms:

⚠️ Attention: A hum or howl from the front axle at a speed of 60–80 km/h is the first sign of wear on the bearings or final drive gears. If the noise goes away when you turn the steering wheel, the problem may be in the CV joint and not in the gearbox.

• 🔊 Extraneous sounds: hum, howl or crunching sound when driving (increases during acceleration).
• 💧 Oil leaks: traces of oil on the gearbox housing or under the car (usually the oil seals or gasket are to blame).
• 🔄 Vibrations: noticeable shaking in the steering wheel or body during acceleration (may indicate an imbalance in the driveshaft or bearing wear).
• 🚗 Deterioration in handling: The car “pulls” to the side when driving in a straight line.

If you ignore these signs, gear wear will lead to gearbox jamming — in this case, a complete replacement of the unit will be required, which will cost 80–120 thousand rubles. For comparison: timely replacement of oil and seals costs 5–10 thousand rubles.

Symptom	Probable Cause	Repair cost (approx.)
Noise when driving	Worn bearings or gears	15 000–40 000 ₽
Oil leak	Worn shank seal or gasket	3 000–8 000 ₽
Vibrations at speed	Driveshaft imbalance or differential play	10 000–30 000 ₽
The car pulls to the side	Wear of differential side gears	25 000–60 000 ₽

Front gearbox diagnostics: how to check it yourself

Before going to the service center, you can carry out preliminary diagnostics:

1. Check for leaks: Inspect the gearbox housing (located under the hood, next to the variator). Oil on it or puddles under the car are a signal to action.
2. Listening to Noises: On a flat road, accelerate to 60–80 km/h and listen. A hum at the front is a sign of problems with the gearbox, at the rear - with the rear axle or wheel bearings.
3. Checking the backlash: Jack up the front wheel and rock it horizontally. Play of more than 1–2 mm may indicate wear of the differential bearings or gears.

For an accurate diagnosis you will need:

• 🔧 Removing the engine protection - for access to the gearbox.
• 🔍 Checking the oil level - its lack accelerates wear and tear.
• 📏 Backlash measurement - a special tool (play meter).

Repairing the front gearbox: step-by-step instructions

Gearbox repair Murano Z51 - a labor-intensive process that requires experience and tools. If you are not confident in your abilities, it is better to contact the service. However, some operations (for example, replacing oil seals) can be performed independently.

Drain the oil from the gearbox|Remove the driveshaft|Disconnect the axle shafts|Prepare new oil seals and gaskets|Clean the housing from dirt-->

Main stages of repair:

1. Oil drain: Unscrew the drain plug (24mm wrench) and drain the oil into a container. B Murano Z51 The volume of oil in the gearbox is about 0.8 liters.
2. Removing the driveshaft: Disconnect it from the gearbox flange (you will need a 12mm wrench for the bolts).
3. Disassembling the gearbox:
   • Remove the shank flange (a puller will be required).
   • Remove the outer bearing and seal.
   • Disassemble the differential, check the condition of the satellites and gears.

Replacing worn parts: Bearings, seals, gears (if necessary).

Assembling and filling oil: Use only original oil Nissan Differential Gear Oil Hypoid Super GL-5 75W-90 (article KE900-90132).

⚠️ Attention: When disassembling the gearbox, be sure to mark the position of the gears and bearings - incorrect assembly will lead to accelerated wear. Also check the condition cardan shaft crosspieces — its backlash can simulate a gearbox malfunction.

What to do if there is still a hum after the repair?

If the hum does not go away after replacing the bearings or seals, the reason may lie in:

- Incorrect adjustment of the gap in the main pair (special tool required).

- Wear of differential gears (needs replacement).

- Damage to the gearbox housing (in this case, only replacing the assembly will help).

Selection of spare parts: original vs analogues

When repairing the front gearbox Murano Z51 It is important to use quality spare parts. Original parts from Nissan guarantee compatibility, but are expensive. An alternative is proven analogues.

Detail	Original article	Analogue (brand, article)	Approximate price
Shank seal	38340-4M000	SKF VKBA 3639	1 200–2 500 ₽
Differential bearing	38100-4M005	NTN 6206LLU	1 800–3 000 ₽
Gearbox gasket	38371-4M000	Victor Reinz 71-34500-00	500–1 200 ₽
Gear oil	KE900-90132	Mobil Mobilube GX 75W-90	600–1,000 ₽/l

When choosing analogues, pay attention to:

• 🔍 Compatible with hypoid gears - not all oils GL-5 fit.
• 🛡️ Seal quality — cheap seals quickly begin to leak.
• 🔧 Availability of guarantee - original parts from Nissan They provide a 12 month guarantee.

Prevention: how to extend the life of the front gearbox

Front gearbox life Murano Z51 depends on operating and maintenance conditions. Follow these guidelines:

• 🛢️ Change the oil every 60 thousand km - even if the manufacturer claims that it is “for the entire service life”. Under Russian conditions (temperature changes, off-road conditions), oil loses its properties faster.
• 🚗 Avoid sudden starts and towing heavy trailers - this increases the load on the gearbox.
• 🔧 Check the oil level at each maintenance - its leakage leads to dry friction and accelerated wear.
• 🛑 Don't ignore the first signs of trouble — hum or vibration is easier to eliminate at an early stage.

Pay special attention to the choice of oil. For Murano Z51 suitable only GL-5 75W-90 with approval for hypoid gears. Use of oil GL-4 or universal transmission fluids will lead to premature gear wear.

If you often drive off-road or tow a trailer, reduce the oil change interval to 40 thousand km. It is also recommended to install gear protection - this will protect it from mechanical damage.

Common repair mistakes and how to avoid them

Even experienced craftsmen sometimes make mistakes when working with the front gearbox Murano Z51. Here are the most common:

1. Incorrect adjustment of the gap in the main pair - leads to hum or jamming. To adjust, you need a special tool (indicator and probes).
2. Use of low-quality oil seals - cheap analogues begin to leak after 5-10 thousand km.
3. Incomplete oil change — if you do not rinse the gearbox before adding new oil, old deposits will accelerate wear.
4. Ignoring the condition of the driveshaft — play in the crosspiece or shaft imbalance can simulate a gearbox malfunction.

⚠️ Attention: When assembling the gearbox, never use sealant instead of a gasket - this will lead to clogging of the oil channels and overheating of the unit. Original gasket 38371-4M000 It is inexpensive, but prevents serious problems.

If you are not confident in your skills, entrust the repair to professionals. Errors when assembling the gearbox can result in its complete failure and costly replacement.

FAQ: Answers to frequently asked questions

Is it possible to drive with a noise in the gearbox?

In the short term, yes, but the longer you put off repairs, the more the gears and bearings wear out. In the worst case, the gearbox may jam, which will lead to an accident. At the first sign of a hum, check the oil level and contact service.

What kind of oil to fill in the front gearbox Murano Z51?

Only GL-5 75W-90 with approval for hypoid gears. Original oil Nissan (article KE900-90132) or analogues: Mobil Mobilube GX 75W-90, Castrol Syntrax Long Life 75W-90.

How much does it cost to replace a shank seal?

The cost of service work is 3,000–6,000 rubles, plus the price of the oil seal (1,200–2,500 rubles). If you change it yourself, it will take 2-3 hours and you will need a puller.

What is the difference between a gearbox Murano Z51 from X-Trail T32?

B Murano Z51 the gearbox is integrated into the variator housing, and in X-Trail T32 it is issued separately. The gear ratios and differential design are also different.

Is it possible to repair the gearbox or just replace it?

In most cases, the gearbox must be repaired (replacement of bearings, seals, gears). A complete replacement is required only if the case is damaged or all internal parts are critically worn.