Crankshaft oil seal <em>Nissan Almera Classic</em>: how to diagnose and replace without errors

Nissan Almera Classic (especially models B10 And N16 with engines GA16DE And QG15DE/QG18DE) is a reliable car, but even it is not immune to wear of the crankshaft seals. An oil leak through the front or rear oil seal is a problem that many owners notice too late, when major repairs are already required. In this article we will look at how diagnose the problem yourself, what tools are needed for replacement, and why oil may continue to ooze even after installing a new oil seal.

Crankshaft oil seals are rubber products that prevent oil from leaking out of the engine where the shaft exits. On Almera Classic there are two of them: front (from the timing side) and rear (from the gearbox side). The first one fails more often due to more severe operating conditions, but replacing it is also easier. It is more difficult to change the rear oil seal - you will have to remove the box or at least its casing, but it also leaks less often. The main mistake of car owners is ignoring the first signs of wear, which leads to oil starvation of the engine and accelerated wear of the turbine (if equipped).

Signs of wear on the crankshaft oil seal Nissan Almera Classic

First signal - oil stains under the car after parking. But this does not always indicate the oil seals: the oil filter, pan gasket or valve cover could be leaking. To pinpoint the problem, inspect:

• 🔍 Front oil seal: Oil on the timing belt, bottom of the belt cover, crankshaft pulley. If the belt is in oil, it be sure to replace, otherwise it will slip and bend the valves.
• 🔧 Rear oil seal: oil at the junction of the engine and gearbox, on the flywheel (visible through the inspection window in the clutch housing). It is often confused with a leaking gasket on the rear cover of the internal combustion engine.
• 💨 Smoke from the exhaust: If the oil seal allows oil into the crankcase ventilation system, it burns in the cylinders, producing bluish smoke.
• ⚠️ Reduced oil level without visible leaks - a sign that it goes through the oil seal into the box (relevant for the rear).

On Almera Classic with engine QG18DE There is a peculiarity: the front oil seal often “squeezes out” due to a clogged crankcase ventilation system. If you don't clean it PCV valve (located in the valve cover), the new oil seal will last 10–15 thousand km at most. Also on these engines there is a defect in the seat for the oil seal - it has to be restored repair sleeve.

⚠️ Attention! If oil is visible on the timing belt, don't start the engine until the leak is eliminated. Oil corrodes the rubber of the belt, and it may break, which may Almera Classic with motors GA16DE/QG18DE leads to bending of valves.

What seals to put on Nissan Almera Classic: original vs analogues

Original oil seals from Nissan have articles:

• 🔄 Front oil seal: 15025-4M500 (for GA16DE) or 15025-5M50A (for QG15DE/QG18DE).
• 🔙 Rear oil seal: 15026-4M500 (common to most motors).

The price of the original is from 1,200 to 2,500 rubles per piece. But many people use analogues that are cheaper and sometimes even more durable:

Brand	Article (front/rear)	Price, ₽	Features
Corteco	20016003/20016004	800–1 500	Good quality rubber, but the seat diameter may differ by 0.1–0.3 mm.
Elring	545.170/545.180	900–1 800	Durable, but require careful installation - easy to damage when pressed.
SKF	17465/17466	1 100–2 000	The best option in terms of price/quality ratio is often offered in services.
Nipparts	N4711010/N4711020	600–1 200	A budget option, but the resource is lower - enough for 50–70 thousand km.

When choosing an analogue, be sure to check internal and external diameters, as well as the width of the seal. For example, for Almera Classic N16 with QG18DE the oil seal from Renault Megane 2 (article 7701473468), but only if the shaft diameter matches (checked with a caliper).

Tools and preparation for replacing the crankshaft oil seal

For replacement front oil seal on Almera Classic you will need:

• 🔧 A set of sockets and keys (required) 10 mm, 14 mm, 17 mm).
• 🔨 Crankshaft pulley puller (or two mounting crowbars).
• 🛠 Mandrel for pressing the oil seal (can be made from a suitable pipe).
• 🧰 Sealant Loctite 574 or ABRO 11-AB (for rear oil seal).
• 🧴 Carburetor cleaner or kerosene (to degrease the seat).

For rear oil seal Additionally you will need:

• 🔧 Removing the gearbox (or at least its casing).
• 🔨 Flywheel puller (if you need to remove it).
• 📏 Caliper for checking the seat.

Before starting work:

1. Drain the oil and antifreeze (if you are removing the pump).
2. Disconnect the battery (remove the negative terminal).
3. Install the piston of the 1st cylinder to TDC (according to the marks on the pulley and timing cover).

Drain the oil and antifreeze|Disconnect the battery|Set TDC of the 1st cylinder|Prepare a mandrel for the oil seal|Buy a new oil seal and sealant-->

⚠️ Attention! On Almera Classic with QG18DE when replacing the front oil seal Be sure to check the condition of the timing belt. If it is in oil or its age is more than 4-5 years, replace it along with the rollers. The cost of the belt (~2,000 ₽) is not comparable to the cost of repairs after a break.

Step-by-step replacement of the front crankshaft oil seal

Algorithm for engines GA16DE And QG15DE/QG18DE similar, but there are nuances:

1. Remove the alternator belt (loosen the tension roller with a key on 14 mm).
2. Remove the crankshaft pulley:
   • Wedge the flywheel through the inspection window with a screwdriver.
   • Unscrew the pulley bolt (tightening torque - 100–120 Nm).
   • Remove the pulley with a puller or carefully pry it off with pry bars.
3. Remove the lower timing belt cover (4 bolts per 10 mm).
4. Remove the old oil seal:
   • Pry it off with a screwdriver or a special puller.
   • Clean the seat from dirt and old sealant.
5. Install a new oil seal:
   • Lubricate the seal lip with engine oil.
   • Press in with a mandrel (or a pipe of suitable diameter) until it stops.
   • Check that the oil seal is seated evenly - distortions are unacceptable!

On QG18DE after installing the seal be sure to check the crankshaft pulley runout. If it exceeds 0.3 mm, the pulley needs to be replaced - otherwise the oil seal will quickly fail. Also, these motors often wear out. oil pump o-ring (article 15010-4M500), which is nearby and may leak.

Replacing the rear oil seal: difficulties and nuances

Rear oil seal on Almera Classic It is more difficult to change - access to the flywheel is required. There are two options:

1. Partial parsing (without removing the box):
   • Remove the starter and clutch cover.
   • Unscrew the flywheel bolts (there are 6 of them, the tightening torque is 70–80 Nm).
   • Pry up the flywheel with pliers and remove it (a puller may be required).
2. Full analysis (with box removed):
   • Necessary if the oil seal is “coked” or the seat is damaged.
   • Requires draining the oil from the box and removing the drives.

After removing the flywheel:

1. Remove the old oil seal (it is located in the rear engine cover).
2. Clean the seat and apply a thin layer of sealant.
3. Install the new oil seal using a mandrel, lubricating the working edge.
4. Check status gearbox input shaft oil seal (article 30501-4M500) - it is also often changed at the same time.

On Almera Classic with GA16DE The rear oil seal may leak due to deformation of the rear engine cover. In this case, the cover will have to be ground or replaced (part number 11110-4M500, price ~5,000 ₽).

What to do if the oil seal does not press in?

If the new oil seal does not fit into the seat, check:

1. **Shaft diameter** - it may be worn out (normal for Almera Classic: 24.98–25.00 mm).

2. **Condition of the cover** - if it is deformed, the seal will be skewed.

3. **Gland seal brand** - some analogues (for example, Nipparts) may have inaccurate dimensions.

As a last resort, use repair sleeve (article 15025-VN400), but this is a temporary solution.

Common replacement mistakes and how to avoid them

Even experienced craftsmen make mistakes that lead to repeated leaks. Here are the most common:

• 🛑 Incorrect pressing: the oil seal is driven in with a hammer without a mandrel → distortion and rapid wear. Solution: Use a pipe or special tool.
• 🛑 Ignoring crankcase ventilation: clogged PCV valve creates excess pressure, which squeezes out the seal. Solution: clean the valve (located in the valve cover).
• 🛑 Saving on sealant: the rear oil seal is installed without sealant → leaks through microgaps. Solution: use Loctite 574 or ThreeBond 1211.
• 🛑 Untested flywheel: flywheel runout more 0.15 mm destroys the seal. Solution: sharpen or replace the flywheel (part number 12300-4M500).

On Almera Classic with QG18DE after replacing the oil seal sometimes appears noise from the timing belt. The reason is an incorrectly installed belt or rollers. Check the belt tension: when pressing with your finger, the deflection should be 5–7 mm.

Cost of service work vs independent replacement

Prices for replacing oil seals in services vary depending on the region and complexity of the work:

Type of work	Cost, ₽ (Moscow)	Cost, ₽ (regions)	Working hours
Replacing the front oil seal	3 500–5 000	2 500–3 500	2–3 hours
Replacing the rear oil seal (without removing the box)	6 000–8 000	4 000–6 000	4–5 hours
Replacement of the rear oil seal (with removal of the box)	12 000–15 000	8 000–10 000	6–8 hours
Replacement of both oil seals + timing belt	10 000–14 000	7 000–9 000	5–7 hours

Self-replacement will only cost the cost of spare parts (~2,000–4,000 RUR), but requires skills. For example, to remove the flywheel on Almera Classic needed special puller (article J-33029), without which the crankshaft can be damaged.

If you decide to do it yourself, put it to work all day - especially if it's the rear oil seal. And don't forget about torque wrench for tightening the bolts (torques are indicated in the repair manual).

FAQ: Frequently asked questions about crankshaft oil seals Nissan Almera Classic

Is it possible to drive with a current oil seal if the oil is consumed at 1 liter per 1,000 km?

In the short term, yes, but it is dangerous. With this oil consumption, the engine operates in mode oil starvationwhich leads to:

• Accelerated wear turbines (if there is one).
• Cranking liners crankshaft
• Overheating of the piston group.

The maximum you can count on is 2–3 weeks drive carefully until repairs are made. But it's better not to take risks.

How to distinguish a front oil seal leak from a valve cover gasket leak?

Inspect:

• If oil on the timing belt or pulley → the front oil seal is leaking.
• If oil on spark plug wells or along the cylinder head → the valve cover gasket is at fault.
• If oil at the junction of engine and gearbox → rear oil seal or rear cover gasket.

Can also be placed under the car blank cardboard at night - by the location of the spot it will be clear where the leak is coming from.

Do I need to change the oil after replacing the oil seal?

Yes, if:

• Oil old (more than 5,000 km).
• They hit him rubber particles from a worn oil seal.
• Was severe overheating engine due to oil starvation.

If the oil is fresh (less than 2,000 km), you can get by partial replacement (drain 2-3 liters and add a new one).

What happens if you don't replace the oil seal on time?

The consequences depend on which seal is leaking:

• Front oil seal:
  • Oil will get on timing belt → break → bend of valves (~50,000 ₽ repair).
  • Pollution generator and pump → their failure.
• Rear oil seal:
  • Oil will get into gearbox → wear of automatic transmission clutches or manual transmission bearings.
  • Pollution clutch → slipping, vibration.

In both cases repairs will cost 3–5 times morethan timely replacement of the oil seal.

Is it possible to use improvised means (for example, a head from a kit) instead of a mandrel?

Yes, but with reservations:

• Head diameter should match exactly with the outer diameter of the oil seal.
• The edges of the head should be smooth (without burrs), otherwise you will damage the oil seal.
• Better to use metal pipe of a suitable diameter - it distributes the force more evenly.

On Almera Classic Suitable for front oil seal 27 mm head, for the rear - 32 mm.