top of page

Search Results

4 items found for ""


    You’ve no doubt heard about the dreaded Crank Hub Failure on BMW’s S55-engined M-cars. As the S55 is fitted to the high-performance, very tuneable M4, M3 and M2 Comp models, it seems like an uncharacteristic error by Munich’s finest engineers. So, as the owner of one of these cars, should you be aware of this problem? Unfortunately, yes, you should. So what’s the S55 & N55's Crank Hub problem? In pretty much any modern engine, high-performance or otherwise, the crankshaft drives the camshafts via a belt or chain. Any unintended slippage of this chain will vary the timing - which can ultimately be pretty catastrophic, as a rapidly rising piston gets to meet several fast moving valves. So it’s a bit of a mystery to the world quite why BMW’s engineers would decide to simply secure the S55’s crank hub, with its geared teeth driving the timing chain, by simply bolting it up really, tightly with a high-friction sintered washer in between. No keyway, no pins used to locate it, just a load of torque on the bolt - and hope for the best! The infamous ‘S55 crank hub failure’, as it has become known, is that fateful moment where either a high shock loading from a gearshift or over time, the engine’s vibrations and harmonics loosen the crank bolt. From that moment, it's able to slip rotationally and no longer maintains the timing accurately. Which BMWs does it affect? Let’s keep this in perspective – our estimate would be that under 10% of S55 engines ever suffer from a spun crank hub in their lifetime. The issue seems to affect modified cars as well as completely standard ones with full BMW service history, but clearly the higher the state of tune, the higher the risk. It seems that every S55 engine is different, just as everyone’s driving style is different. It’s worth adding that the S55 shares the same flawed crank hub design as the ever-popular N55 engine (and also many of those parts are also shared with the N54). So although the N54 and N55 can occasionally experience spun crank hubs, it’s more of an isolated and uncommon issue on these engines. Why is that, when the design is shared with the S55? Simply because it’s so much easier to extract much higher power outputs from the S55 engine – and these additional internal loads inevitably mean a higher likelihood of failures elsewhere. So if you are running a high-powered, or hard-driven N55 or N54, we’d certainly recommend the Crank Hub upgrades to protect your engine just as much as we would for S55 owners. How can I tell if Crank Hub Slip has happened? Don’t expect any warning symptoms of crank hub failure. It's not something that occurs gradually over time, nor is it something that you can check for. If your S55 crank hub is going to slip, it will occur all of a sudden. If it happens to you, when the ECU senses that the timing has slipped by a certain small amount, it triggers a “Drivetrain Failure” on the dashboard with accompanying rough running, rough idle and reduced engine performance. This is your best-case scenario. The next stage is when the timing goes out by a greater amount the ECU will actually prevent the engine from starting, to protect itself from the risk of damage. Annoying as that may seem, it’s the ECU doing a good job of shutting the engine down to save you from some really big bills. In the cases above, the problem is fixed by replacing the crank hub and carefully resetting the timing. Once the crank hub has slipped like this, the only course of action is replacement of the failed hub, as they are ‘one use’ only from BMW. Simply retightening the crank bolt will not work. This won’t be a cheap fix, but you can console yourself that no internal engine damage is likely. However, in the worst cases, a spun crank hub will cause serious internal engine problems, requiring a full engine rebuild. Such damage will likely occur if the crank hub slips at high engine rpm, such as a downshift on-track, or if you continue to drive your S55 with an already spun crank hub. How to fix my S55 / N55 once Crank Hub Slip has happened? There are two parts to this answer. Firstly, preventative steps to take before your S55 experiences the dreaded Crank Hub slippage. Secondly, assuming crank hub failure has happened to you, how to repair your engine to make sure it doesn’t ever happen again. Let’s start with preventative measures: a Crank Bolt ‘Capture Plate’ is an affordable first step to protect a car that has shown no slippage issues and is still running fine. Having checked that the engine is timed perfectly, the capture plate fits over the head of the crank bolt and is secured to the crank pulley assembly via 8 bolts. The result? With the capture plate bolted up tight, the crank bolt simply cannot come undone. This solution will be enough for most vehicles, and although fitting typically takes 4-5 hours of labour it could save you an awful lot more cost and heartache in the longer run. For the ultimate preventative measure, which we’d strongly recommend if you’re planning either serious track use, or running your engine at high power outputs, install a ‘Single Piece Crank Hub’, machined from a solid billet of hardened steel. We highly recommend fitting this along with the Capture Plate, so you’ve got absolute peace of mind for the lifetime of your car. Whilst it’s an involved job for an expert to compete this upgrade work now, you’ll be safe in the knowledge that you’ve corrected BMW’s problem once and for all. But you have a further choice to make: a pinned or an unpinned Single Piece Crank Hub. As MMR Performance now offers two versions of the Single-Piece Crank Hub, which is best for you, pinned or unpinned? For most standard to Stage 1 tuned S55 & N55 engines, the unpinned MMR Single-Piece Crank Hub is more than sufficient. Installation is more straightforward as the end of the crankshaft does not need to be precision drilled to mount the four locating dowels. However, for high power/torque engines tuned beyond this level, we recommend the upgraded pinned version of the Crank Hub that incorporates the 4-pin dowel drive mounting for the ultimate engine security. Fitment of the pinned Crank Hub requires four holes to be drilled in the end of your crankshaft to insert the 4 pins dowels that the MMR hub uses. It's the most extreme solution, but without question it's the ultimate answer. What if Crank Hub Slip has already happened? Finally, if crank-slip has already occurred, bad luck. Even if no engine damage has occurred, you now have no choice but to replace the affected components, as they are single-use parts from BMW. Once any slipping, even the slightest amount has occurred the bolt cannot be re-tightened. This is your moment of choice. BMW will fix the problem with a new set of identical BMW replacement parts. But most knowledgeable owners opt not to re-fit these factory parts again, in the sure knowledge that the same problem occurring again is a distinct possibility. Rather, the wiser choice is to now install our Single Piece Crank Hub secured with our Capture Plate. Although you’ve got the financial pain of fixing the crank hub slippage, at least you’ll now have absolute peace of mind that for the lifetime of your car.

  • Grow Your Blog Community

    With Wix Blog, you’re not only sharing your voice with the world, you can also grow an active online community. That’s why the Wix blog comes with a built-in members area - so that readers can easily sign easily up to become members of your blog. What can members do? Members can follow each other, write and reply to comments and receive blog notifications. Each member gets their own personal profile page that they can customize. Tip: You can make any member of your blog a writer so they can write posts for your blog. Adding multiple writers is a great way to grow your content and keep it fresh and diversified. Here’s how to do it: Head to your Member’s Page Search for the member you want to make a writer Click on the member’s profile Click the 3 dot icon ( ⠇) on the Follow button Select Set as Writer

  • Design a Stunning Blog

    When it comes to design, the Wix blog has everything you need to create beautiful posts that will grab your reader's attention. Check out our essential design features. Choose from 8 stunning layouts Your Wix Blog comes with 8 beautiful layouts. From your blog's settings, choose the layout that’s right for you. For example, a tiled layout is popular for helping visitors discover more posts that interest them. Or, choose a classic single column layout that lets readers scroll down and see your post topics one by one. Every layout comes with the latest social features built in. Readers can easily share posts on social networks like Facebook and Twitter and view how many people have liked a post, made comments and more. Add media to your posts When creating your posts you can: Upload images or GIFs Embed videos and music Create galleries to showcase a media collection Customize the look of your media by making it widescreen or small and easily align media inside your posts. Hashtag your posts Love to #hashtag? Good news! You can add tags (#vacation #dream #summer) throughout your posts to reach more people. Why hashtag? People can use your hashtags to search through content on your blog and find the content that matters to them. So go ahead and #hashtag away!

  • Now You Can Blog from Everywhere!

    We’ve made it quick and convenient for you to manage your blog from anywhere. In this blog post we’ll share the ways you can post to your Wix Blog. Blogging from Your Wix Blog Dashboard On the dashboard, you have everything you need to manage your blog in one place. You can create new posts, set categories and more. To head to your Dashboard, open the Wix Editor and click on Blog > Posts. Blogging from Your Published Site Did you know that you can blog right from your published website? After you publish your site, go to your website’s URL and login with your Wix account. There you can write and edit posts, manage comments, pin posts and more! Just click on the 3 dot icon ( ⠇) to see all the things you can do. #bloggingtips #WixBlog

bottom of page