The sole purpose of oil seals is to prevent engine oil from leaking out of the cylinder block. An oil seal is installed in the area of the block where the crankshaft goes outside. If oil leaks are found in this place, the crankshaft rear oil seal must be replaced.
Crankshaft oil seals are made of heat-resistant materials - silicone or fluoroelastomer rubber. They look like O-rings, the diameter of which matches the diameter of the crankshaft.
The most important sign of the need to replace the rear oil seal is the presence of traces of engine oil drips at the junction of the engine crankcase and the gearbox. Oil can enter the clutch housing, settle in a layer on its walls and contaminate the disc. All this leads to clutch slippage and a significant increase in oil consumption.
In cars, the engine of which is located along the engine compartment, and the gas distribution occurs using a metal chain drive, the oil seals are installed directly in the crankshaft shield in front of the support bearing. For front-wheel drive, or if the car uses a rubber belt in the timing, the oil seals are located in the block itself, since the use of shields is not required here.
On the outside of the seal, the manufacturer affixes a special inscription. It determines the direction of movement of the crankshaft. Given this information, you can install a new oil seal with your own hands without errors.
How is the rear crankshaft oil seal replaced?
The procedure for replacing the rear crankshaft oil seal requires the dismantling of many components. You will have to dismantle the gearbox while carefully inspecting all the components. To perform this operation, place the machine on a lift or inspection pit. Fix the wheel with stops and then get to work.
Advice. It is advisable that someone help you when dismantling the box, as this is a difficult and time-consuming procedure. When working, immediately start sorting the bolts so that the subsequent assembly does not turn into a continuous torment. Place bolts and small parts from each assembly in a separate box or on a separate blank sheet. Make the appropriate signature on each of them.
Removing the transmission for a car with rear wheel drive
Remove the driveline first, then disconnect the starter. Next comes the clutch slave cylinder, which is best removed entirely with the clutch hose. Remove the speedometer cable, then the reverse toad wiring, disconnect the gearbox handle so that it does not interfere with the gearbox dismantling, then you can release the gearbox slide in the passenger compartment.
Along the outline of the box, find the bolts connecting it to the engine, and remove them. Next, remove the rear gearbox mount. If necessary, remove the muffler pipe; after dismantling it, the work will go easier and faster.
Remove the basket, clutch disc, flywheel and shield. This will give you access to the oil seal. Be careful with the transmission, it is still heavy; when removing it, the help of a partner is desirable.
Place the removed transmission on a suitable wooden surface, taking care not to damage the structural parts of the transmission.
Removing the transmission for a car with front wheel drive
Loosen the axle nut and remove the left front wheel of the machine. Then unscrew the nut completely, after which you will be able to move the rack off the axle shaft. Take her aside. Most often you have to dismantle the steering pin in the fastener, but sometimes the rack comes out on its own. If the strut does not move, you will have to remove the steering pin.
Then unscrew the second axle nut and drown with a copper adapter. This is necessary so that when you remove the box, it comes out more easily. Remove all attachments from the checkpoint:
- cable,
- speedometer sensor,
- backstage,
- clutch drive,
- reverse toad wires.
Then remove the pillows. The further operation to replace the oil seal is performed in the same way as described above for a rear-wheel drive car.
All the gearbox mounting bolts are removed in a circle. After which it moves with the semiaxes. To remove the box from the clutch with the engine, slightly release it down and immediately slide it back. Then you can remove the clutch basket and flywheel using the head and ratchet wrench.
How to dismantle the rear oil seal and install a new one: step by step instructions
The further procedure for replacing the rear crankshaft oil seal is the same on rear- and front-wheel drive vehicles. Remove the rear seal housing, install a new one, then put the housing back in. It is often found that the gasket of the seal body is damaged, therefore, after removing it, it is necessary to carefully inspect and assess the condition. If necessary, you will have to replace it.
The very replacement of the rear oil seal is done as follows. Align the self-tapping screw on the edge of the gland, lightly hit it on the head so that it enters the metal more easily. Then screw it into the oil seal.
The best option is to use a special metal screw for this, which is widely used in repairs to fix the profile. Screw the self-tapping screw into the oil seal a few turns so that it is tightly held in it. Gently apply pliers and remove the oil seal.
Most often, the oil seal is pulled freely along with the self-tapping screw. However, if the diameter of the part is too large, then one self-tapping screw will not cope. In this case, you will have to screw in at least two, one on each side. Then, using two pliers, pull out the oil seal. The help of a partner is also desirable here.
Remember to inspect the crankshaft bearing during the oil seal replacement procedure. If the input shaft of the gearbox entering it, when turning, makes a grinding and other noise or sticks on the move, then the bearing must be replaced. Similarly, the release bearing is checked for malfunction. When scrolling, it should not make any sounds or jam.
After that, you can install a new oil seal in place and reassemble the entire structure. When installing the basket, it is imperative to check whether there are cracks on it, whether the petals are bent, whether there is damage to the wire ring passing through the basket. To do this, turn the basket over, the whole ring will be clearly visible.
The clutch fork must also be free of cracks. Check its working edge for the degree of wear, because it is with this part that the fork pushes the release bearing. The fork should not show any cracks or it will have to be replaced.
Examine the disc carefully. If it can be seen that it does not have enough stock, or it is already worn out to the very rivets, this part also needs to be replaced. At the time of installation in place of the basket and disc, you will have to center the clutch basket using a mandrel. In the absence of a mandrel, you can do it yourself. To do this, sharpen an ordinary brush handle under the cone. This cone will allow you to center the element.
You can also use the transmission input shaft to center the disc basket. Install it in the hole and secure the clutch mechanism. Then the gearbox can be installed and secured in its place.
