<em>Nissan Murano Z51</em>angular gearbox: device, diagnostics and do-it-yourself replacement

Nissan Murano Z51 is a crossover that has gained popularity due to its reliability and comfort, but even it has weaknesses. One of them is bevel gear, responsible for transmitting torque from the driveshaft to the wheels. This part experiences enormous loads, especially when used in difficult conditions: off-road, sudden starts, overloading the vehicle. As a result, the gearbox wears out, backlash, noise and vibration appear, which over time can lead to complete failure of the unit.

In this article we will analyze bevel gear design Murano Z51, typical malfunctions, methods for diagnosing and repairing them. You will also learn how to choose a high-quality analogue or original spare part, how much a replacement costs in the service, and whether you can handle the work yourself. We will pay special attention a unique feature of this generation gearbox - a weak point in the bearing assembly, which is often ignored even by experienced craftsmen.

Design and principle of operation of an angular gearbox Nissan Murano Z51

Angular gearbox (aka cross-axle differential or transfer case in all-wheel drive versions) in Murano Z51 performs two key functions:

• 🔄 Changing the direction of torque transmission at an angle of 90° from the driveshaft to the wheel axles.
• ⚙️ Reducing the gear ratio to increase traction (in models with all-wheel drive).
• 🚗 Power distribution between wheels of the same axle (differential).

Structurally, the unit consists of:

• 🔧 Housings (aluminum alloy, less often - cast iron).
• ⚙️ Drive and driven gears (hypoid gear for smooth operation).
• 🧲 Bearing units (a common cause of breakdowns!).
• 🔄 Differential (open type in basic versions, lockable in Murano with the system All-Mode 4x4-i).
• 🛢️ Oil seals and seals (leak when worn).

Feature Murano Z51 - use hypoid transmission in the gearbox, which reduces noise, but requires special oil with extreme pressure additives (for example, GL-5 75W-90). Ignoring this rule leads to accelerated wear of the gears.

Signs of a bevel gear malfunction: when to sound the alarm?

The first symptoms of problems with the gearbox are often attributed to wear of the suspension or transmission. However there is characteristic features, which directly indicate problems in this node:

Symptom	Probable Cause	Danger level
🔊 Hum or howl when driving (intensifies at speeds of 60–90 km/h)	Worn bearings or gears, lack of oil	⚠️ Medium (may lead to jamming)
🌀 Vibration on the body or steering wheel during acceleration	Play in bearings, shaft deformation	❌ High (risk of differential destruction)
🛑 Clicks when turning (especially in parking lots)	Wear of differential pinions or spline joints	⚠️ Average (progresses over time)
💧 Oil leaks under the gearbox	Worn seals or crack in the housing	❌ Critical (will lead to oil starvation)
🚗 The car "steals" to the side when moving in a straight line	Seized bearing or differential	❌ Critical (emergency!)

⚠️ Attention! If you hear when driving backwards metallic grinding, this is a sign critical wear of hypoid pair gears. In this case, operating the vehicle is prohibited - the gearbox may jam at any time.

For an accurate diagnosis, perform a simple test:

1. Raise the car on a lift or hang the rear (front) axle.
2. Spin the wheel manually - play or extraneous sounds will indicate a problem.
3. Check the oil level in the gearbox (through the filler plug).

Bevel gear diagnostics: step-by-step instructions

Before sinning on the gearbox, rule out other possible causes of noise and vibration:

• 🔧 Suspension (racks, silent blocks, balls).
• ⚙️ Cardan shaft (crosspieces, outboard bearing).
• 🛞 Wheel bearings.
• 🔄 CV joints (crunch when turning).

If these components are in order, proceed to diagnose the gearbox:

Method 1: Listening on a lift

Start the engine, shift into gear and listen to the sounds coming from the gearbox. A hum at all speeds is a sign of bearing wear. If the noise disappears when the wheels are hanging up, the problem is in the differential.

Method 2: Checking the play

Grasp the driveshaft flange with your hands and rock it up and down. Backlash more 0.5 mm indicates wear in bearings or seats.

Method 3: Oil Analysis

Drain some oil from the gearbox. The presence of metal shavings or a black color indicates wear on the gears. Normal oil is transparent with a slight amber tint.

⚠️ Attention! B Murano Z51 with the system All-Mode 4x4-i a faulty gearbox can block the switching of drive modes. If the indicator on the panel is on 4WD ERROR, check first wheel speed sensor (located on the gearbox housing).

Original articles and analogues: what to choose for replacement?

When purchasing spare parts for Nissan Murano Z51 important to consider year of manufacture And drive type. Gearboxes for 2WD And AWD differ in gear ratios and differential design.

Detail	Original article	High-quality analogues	Note
🔧 Gearbox assembly (AWD)	38410-4M50A	Febi 38410, GKN 515004	Includes differential and bearings
⚙️ Drive gear	38411-4M50A	Koyo VKBA3405, NSK 513050	Requires paired replacement with slave
🧲 Differential bearing	38430-4M500	SKF VKBA3641, Timken HM89449	Replace only as a set!
🛢️ Flange seal	38426-4M500	Corteco 20033401, Elring 500.130	Use with sealant Loctite 574
🔄 Differential (lockable)	38405-4M51A	GKN 515005, ZF S5-46	Only for versions with All-Mode 4x4-i

💡 Selection advice: If your budget is limited, you can buy remanufactured gearbox (for example, from Cardone or Dorman). However, such nodes serve 30–50% less than the original. For durability, it is better to take new parts from GKN or Febi.

Critical nuance: in gearboxes Murano Z51 2009–2012 model years, the plastic differential bushing often breaks (part number 38406-4M500). Its wear leads to backlash and accelerated destruction of gears. When replacing the gearbox, always check this part!

Replacing the bevel gear Nissan Murano Z51 with your own hands

Replacing a gearbox is a labor-intensive procedure, but if you have tools and an inspection hole, you can do it yourself. You will need:

• 🔧 A set of sockets and keys (especially 24 mm And 32 mm for flanges).
• 🔨 Bearing puller (for disassembling the differential).
• 🛢️ Oil GL-5 75W-90 (volume - 1.2–1.5 l).
• 🧴Sealant Loctite 5980 (for the body).
• 🔧 Torque wrench (flange tightening torque - 120–140 Nm).

Step by step instructions:

1. Drain the oil from the gearbox (square plug 10 mm).
2. Disconnect the driveshaft from the flange (mark the position of the bolts!).
3. Remove the axle shafts (on AWD drives will need to be disconnected).
4. Unscrew the gearbox mount to the bridge (6 head bolts 14 mm).
5. Install a new gearbox, having previously applied sealant to the mating surfaces.
6. Tighten the flange torque wrench (torque - 130 Nm).
7. Fill with oil to the level of the filler plug.

⚠️ Attention! During assembly do not confuse the axle shafts — the left and right have different lengths of the spline part. Installation “the other way around” will lead to vibration and damage to the CV joints.

📌 Service life a new gearbox depends on:

• 🛢️ Oil qualities (change every 60,000 km).
• 🚗 Driving style (abrupt starts reduce the resource).
• 🌡️ Operating conditions (off-roading accelerates wear).

What should I do if there is still a hum after replacing the gearbox?

If the hum persists, check:

- Correct installation of the axle shafts (loose nuts cause vibration).

- Condition of the driveshaft (worn crosspieces also make noise).

- Oil level (underfilling leads to oil starvation).

- Quality of spare parts (defective bearings can hum from the first kilometers).

Cost of work and spare parts: where is it cheaper to repair?

The cost of replacing a bevel gear varies depending on the region and type of service station:

Service type	Cost (RUB)	Note
🔧 Gearbox diagnostics	1 500 – 3 000	Includes play and oil check
🔄 Replacement of gearbox assembly	8 000 – 15 000	Without cost of spare parts
⚙️ Repair (replacement of gears/bearings)	12 000 – 25 000	More expensive than replacing a used unit
🛢️ Changing the oil in the gearbox	1 000 – 2 000	Oil cost - 800–1,500 rub./l

💰 Savings: Purchase used gearbox disassembly will cost 15,000–25,000 rub. (against 40,000–60,000 rub. for a new one). However, the risk of running into a “dead” unit is high - check the play and oil before purchasing!

📍 Where can I order spare parts?

• 🌍 Foreign sites: Amayama, BuyCarParts (cheaper by 20–30%, but long delivery).
• 🏬 Russian stores: Exist.ru, Autodoc (fast, but prices are higher).
• 🔧 Showdown: Bamper.by, Autopiter.ru (risky, but cheap).

Prevention and increase in the life of the angular gearbox

Average gear life Murano Z51 — 150,000–200,000 km. But with proper care, this figure can be increased to 300,000 km. Basic rules:

• 🛢️ Change oil every 60,000 km (in difficult conditions - 40,000 km). Use only GL-5 with permission Nissan KE900-90040.
• 🚗 Avoid abrupt starts with slipping - this kills the differential gears.
• 🌡️ Do not overheat the gearbox (for example, when towing a trailer). Temperature higher 120°C destroys the oil.
• 🔧 Check the play every 20,000 km (especially after off-road driving).
• 🛑 Don't ignore the first signs of trouble — early repairs are cheaper.

❄️ Winter operation: In cold weather, the oil in the gearbox thickens, which increases the load on the bearings. First 5–10 km After a cold start, move smoothly, without jerking.

🔥 What kills a gearbox the fastest?

• 💨 Driving with faulty seals (oil flows out, dry friction begins).
• 🚜 Constant towing or overloading the vehicle.
• 🛣️ Long off-road driving (sand and dirt enter through the breather).
• 🔧 Using low-quality oil (For example, GL-4 instead of GL-5).

⚠️ Attention! B Murano Z51 with the system All-Mode 4x4-i gearbox connected to electronic control unit. If after replacing the unit the Check Engine, required reset adaptations via a diagnostic scanner (for example, Launch X431).

FAQ: Frequently asked questions about the gearbox Nissan Murano Z51

🔧 Is it possible to drive with a hum in the gearbox if it is not strong?

No! Even a slight hum indicates worn bearings or gears. Over time this will lead to jamming gearbox, which at high speed can cause an accident. At the first sign of a malfunction, contact service.

🛢️ What kind of oil to pour into the gearbox Murano Z51?

Official recommendation - Nissan Differential Gear Oil Hypoid GL-5 75W-90 (article KE900-90040). Analogues: Mobil Mobilube GX 75W-90, Castrol Syntrax Long Life 75W-90. Volume - 1.2–1.5 l depending on modification.

🔄 How much does it cost to replace a gearbox seal?

Cost of work - 2,000–4,000 rub. (depending on the region). Original oil seal (38426-4M500) will cost 800–1,200 rub.. When replacing the oil seal, be sure to check the condition of the flange - if there are burrs on it, the entire assembly will need to be replaced.

🚗 Is it possible to install a gearbox from another Nissan?

Theoretically, gearboxes from Nissan Pathfinder R51 (2005–2012) and Infiniti EX35 (2007-2013), but requires VIN verification. The main condition is coincidence gear ratio and differential type.

⚙️ What to do if vibration appears after replacing the gearbox?

Vibration is most often caused by:

1. Incorrect tightening of the propeller shaft flange (torque - 130 Nm).
2. Damage to the splines on the axle shafts.
3. Imbalance of the driveshaft (balancing required).

Check also alignment gearbox and axle - the fastenings may have moved during installation.