Symptoms of an oil leak at the junction of the engine and gearbox on a crossover Nissan Murano second generation (Z51) often become a cause for serious concern for the owner. Many car owners mistakenly assume that oil is leaking from under the body. CVT for a malfunction of the gearbox itself, although in most cases the source of the problem lies in wear of the rear crankshaft cuff. Ignoring this malfunction leads not only to loss of lubrication, but also to the formation of an oil plume, which clogs the cooling radiator and creates a fire hazard on a hot engine.
Replace crankshaft rear oil seal you can do it yourself, but this process requires a deep understanding of the transmission design and the availability of specialized tools. On the model Nissan Murano Z51 With the VQ35DE engine, access to the seal is severely limited by the transmission design, making a simple seal replacement a major repair project. You will have to dismantle the box, which carries the risk of damaging the valve body or skewing the case if you do not follow the strict sequence of actions.
Diagnosis and confirmation of oil seal leaks
Before you begin the complex removal procedure gearboxes, it is necessary to accurately verify the diagnosis. An oil leak can come not only from a worn cuff, but also from the oil pan gasket, crankshaft position sensor, or even the camshaft seal, from which oil flows down the block. Visual inspection from underneath a vehicle can often be deceiving as oil spreads across surfaces and drips in various places, masking the real source of the problem.
Use the brake cleaner and talc method (or special leak detection spray paint) to pinpoint the defect. Clean the bottom thoroughly engine and the junction with the gearbox, then run the engine for a few minutes. If oil begins to appear exactly in the center of the joint in the flywheel area, the diagnosis is confirmed. This is a critical point, as removing the transmission is a labor-intensive process that takes 4 to 8 hours of skilled time.
- 🔍 Inspect the junction of the engine and CVT for fresh pressure leaks.
- 🧹 Use degreaser and talc to identify the direction of oil flow.
- 🛑 Check the engine oil level to prevent loss of more than 1 liter in a short period.
Selection of quality spare parts and necessary tools
The quality itself rear oil seal plays a decisive role in the durability of the repair. Cheap analogues made from low-quality rubber quickly become tanned by high temperatures and pressure in the lubrication system, which leads to repeated leakage after just a few thousand kilometers. For engine VQ35DEinstalled on Nissan Murano Z51, the original oil seal is marked Nissan 31395-AL600, but there are also proven substitutes from manufacturers specializing in seals for Japanese engines.
In addition to the seal itself, you will need a new flywheel (or checking the condition of the old one) and gasket the oil pan, since when the box is removed, the pan often becomes deformed or loses its seal. Also, don’t forget about a set of special keys for removing engine and transmission mounts, which may be stuck on this model. The lack of a suitable tool can lead to stripping of the threads on the mounting bolts, which will significantly complicate the task.
- 🔧 Be sure to prepare a hydraulic stand to support the engine when removing pillows.
- 🛠️ Need a set of sockets, including extensions and universal joints for hard-to-reach places.
- ⚙️ Buy a new flywheel seal and pan gasket complete with sealant.
Preparing the vehicle and dismantling attachments
The first stage of work is to de-energize the vehicle and provide free access to the lower part of the power unit. Remove the negative terminal from the battery to prevent short circuits when working with sensors and wiring. Next, it is necessary to dismantle the engine protection, plastic fender liners and, if necessary, elements of the exhaust system that may interfere with the transmission of the gearbox. On Nissan Murano Z51 It is often necessary to remove the exhaust pipe of the muffler, since it runs too close to the crankcase.
It is also important to disconnect all connectors and cables going to the transmission: gear selector cable, speed sensor, solenoid connectors and crankshaft position sensor wiring. Incorrectly disconnecting the wiring can lead to damaged contacts or broken wires, which will require complex diagnostics in the future. It is better to immediately sort all the bolts and nuts that you unscrew into groups so as not to get confused during assembly.
⚠️ Attention: Before unscrewing the engine mounting bolts, make sure that it is securely secured with a hydraulic strut. A sudden drop in the engine can damage radiators, air conditioning pipes or the cylinder block itself.
- VQ35DE (3.5 l)
- VQ35HR (3.5 l, restyling)
- Other
- I don't know
Removing the gearbox and flywheel
This is the most important and labor-intensive stage, requiring accuracy and physical strength. Gearbox on Nissan Murano It is attached to the engine with powerful bolts, which are often tightened with great force. You will need to remove the right and left engine mounts, as well as the transmission mount. After this, the box will hang only on the pins, and it will need to be carefully moved away from the block so as not to damage the torque converter.
Pay special attention torque converter. It must be completely disconnected from the flywheel before attempting to remove the box, otherwise you will strip the mounting bolts or damage the pump flange. After removing the box you will have access to the flywheel and rear oil seal. The flywheel is held in place by bolts that are tightened with a torque wrench, so you will need a strong wrench or impact driver to remove them.
☑️ Removing the gearbox
Installation of a new oil seal and assembly
Installing a new crankshaft rear oil seal requires the use of a special mandrel or a piece of pipe suitable in diameter. Never drive the oil seal directly with a mallet or hammer, as this may deform its metal body and break the seal. The oil seal should be positioned exactly in the center, without distortion, and its outer edge should fit snugly against the cylinder block.
Before installation, be sure to lubricate the seal lip with fresh engine oil to avoid cranking and dry friction when starting the engine for the first time. Also check the condition of the crankshaft oil seal on the flywheel itself (if there is one) and the shaft surface for scratches. After installing the oil seal, you can begin reassembly, observing the tightening torques of all bolts, especially the torque converter and flywheel mounts.
- 🛢️ Lubricate the working edge of the oil seal with clean engine oil before installation.
- 🔨 Use a mandrel for even pressing, do not hit the edge with a hammer.
- ⚙️ Check the flywheel play and the condition of the splines before installation.
Why is a skewed oil seal dangerous?
If the oil seal is installed skewed, it will begin to leak oil under pressure, even if it visually seems to be tight. This will lead to rapid wear of the edge and repeated leakage after several hundred kilometers.
Typical mistakes and important repair nuances
One of the most common mistakes when replacing an oil seal is Nissan Murano Z51 is the use of silicone sealant where it is not provided for in the design. At the rear cover of the cylinder block and at the junction with the flywheel, sealant can get inside the engine or gearbox, which will cause clogging of the oil passages and failure of the CVT valve body. Sealant is used only at certain joints of gaskets, and its amount must be strictly dosed.
Another problem is improperly tightened flywheel bolts. If they are not tightened sufficiently, the bolts may come loose while the engine is running, causing destruction of the transmission. If tightened too much, the bolts may stretch or break. Always use a torque wrench and follow the manufacturer's recommended tightening torques, which are usually found in the service book.
⚠️ Attention: Do not allow dirt to get inside the engine after removing the pan or box. Even a small grain of sand that gets into the oil channel can cause the crankshaft to scuff or break the piston group.
Before final assembly, rotate the crankshaft by hand a few turns to ensure that the new oil seal is not pinched and that the shaft rotates freely without binding.
Cost of work and final recommendations
Replacing the rear crankshaft oil seal with Nissan Murano Z51 - this is a job that in a service center can cost a significant amount of money due to the difficulty of access and the need to remove the gearbox. On average, the cost of work varies depending on the region and level of service, but it will always be higher than replacing the front oil seal. Saving on the quality of spare parts or trying to do the job “on your knees” often leads to the fact that after six months you have to repeat the whole process again, with double the repair costs.
If you have the necessary skills and tools, doing the replacement yourself can save you money, but it requires a lot of patience. The main rule is to take your time when removing and installing the gearbox. It is critically important to check the condition of the crankshaft shaft for scoring where the oil seal is installed, as even a minor scratch will cause the new seal to immediately leak.
| Work stage | Approximate time (person/hour) | Complexity |
|---|---|---|
| Diagnostics and preparation | 1-2 | Low |
| Removing Attachments | 2-3 | Average |
| Removing the gearbox | 3-5 | High |
| Oil seal replacement and assembly | 2-4 | Average |
In conclusion, repairing the rear crankshaft oil seal Nissan Murano This is a serious undertaking that requires a professional approach. The use of original spare parts, adherence to tightening torques and cleanliness during operation guarantee a long service life of your car after repair. Do not neglect diagnostics before starting work to make sure that the problem is in the oil seal and not in another engine component.
The quality of the oil seal installation and cleanliness during installation are more important than the speed of work. A mistake at the pressing stage may cost you to remove the gearbox again.
Frequently asked questions (FAQ)
How long does it take to replace a rear oil seal on a Murano Z51?
On average, a professional technician will spend 6 to 10 hours on the complete replacement procedure, including removing and installing the transmission. In a garage, this time can increase to 12-14 hours due to the lack of a lift and special equipment.
Is it possible to replace the oil seal without removing the gearbox?
This is almost impossible with the VQ35DE engine in the Murano Z51. Access to the rear cover is blocked by the torque converter and CVT housing. Removing the box is a prerequisite for a quality replacement.
Which oil seal is better to choose: original or analogue?
It is recommended to use the original oil seal Nissan or high-quality analogues from brands specializing in Japanese cars (for example, Sakura or Elring). Cheap Chinese analogues often cannot withstand the temperature conditions of the VQ35DE engine.
Is it necessary to change the engine oil after such work?
Preferably. When removing the gearbox and pan (if it is removed), some of the oil may spill out. Also, if you are replacing gaskets, it is best to add fresh oil to avoid any old oil or sealant residue getting into the fresh grease.
What happens if you drive with a leaky rear oil seal?
Driving with a leaking oil seal will cause the oil level to drop, which can cause the engine to overheat. In addition, oil will drip onto the hot exhaust manifold, creating a fire risk, as well as contaminating the transmission and drives.