BMW N55 Engine Rebuild Project Part 8 – Front Crankshaft Seal DIY (No Special Tools)

Hey guys and welcome back to the SimpleCarGuy channel. I’m still working on my BMW N55 engine rebuild and as one of the last steps, I’m installing a brand new front crankshaft seal. Just like with the rear crankshaft seal, I will not be using any special tools for this job as I think it’s doable with the stuff you already have in the garage. Of course, if you do these often or aren’t sure of my technique, buy the correct tools for the job. However, if you’d like to see my DIY method, this is the video for you! If you’re interested in the rebuild project, check out the link in the description to start from the beginning and don’t forget to give this video a like to support my channel. Now to the job at hand.

If you are doing this with the engine still in the car, you will of course have to remove some parts to get to the seal. Luckily, it’s not nearly as bad as the rear seal. To start with, you’ll remove the underbody protection panel and most of the air ducts that’s in the way on the top of the engine by the radiator and with enough space remove the radiator fan as well. Your transmission oil cooler might be in the way, but you don’t have to remove it. It can be moved to the side. With a lot more space, you can now remove the serpentine belt that’s wrapped around the vibration damper. Now, to remove the 8 screws holding it to the crankshaft, you will need to secure the crankshaft in place or it will move as you try to loosen the bolts. You can get a simple stopper tool for a few bucks and block the crankshaft from moving at the flywheel and release the screws.

Now that you finally have access to the front crankshaft seal, you’ll have to remove it. This can be a little tricky without the special tool, but whatever you do, do not release the main bolt unless you want to be timing the engine as well. The way I removed my seal was by screwing a thin screw into the seal and then pulling it out with a hammer by leveraging it against the engine block. It popped out without much hesitation.

Finally, we are at the install stage and the first step, as always is to really clean the area as well as you can. A good degreaser will help you get rid of any oil on the engine block and insure a good seal. Once everything is clean, the seal can be installed. Once again, you can use the fancy install tool, but I will use what I have.

To install the seal, I use the little plastic cone that it came with and my old seal to get it seated on the crankshaft. No force is really needed here, it should go in easily and once you start feeling a little bit of resistance, grab a mallet and tap it in place. Check that the inner seal is seated properly and not bent over itself as well as the little groves lined up with the seam on the block and then go to town with your mallet. You don’t want to hit it hard, so slow and steady wins the race here. As long as it’s going in evenly, we are getting it done. You also don’t want to hit the seal directly and use the old seal to distribute the weight, this is very important to avoid damage to the new seal. After some time, it will start to feel like it’s not moving anymore and as long as it looks to be in the right stop, you are done with this part.  

The next step is to use a liquid sealing compound to avoid any leaks in the future. There are two different sealants you can use, the one I showed you at the beginning of the video and one I will show you in just a few seconds. Whichever one you use; you will need a primer for good adhesion.

After everything is cured, re-assemble the car and have many more happy miles without an oil leak at the front crankshaft seal. Anyway, thank you guys so much for watching, leave me a comment down letting me know how hard or easy this was for you, subscribe to the channel if it’s your first time watching and I’ll see you in the next one video when we finish the engine and put it back in the car.

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