Prevent Belt Ingestion At The Front Main Seal
Crank Seal Guard Protection KIT for BMW N52, N54, N55, S55 - 335i, 135i
CNC-machined in Canada. Proven fit. Zinc plated hardware + Loctite
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Description
Description
N54 / N55 / N51 / N52 / S55 Crank Seal Protection Plate
A very unexciting part that prevents very exciting repair bills.
This plate has one job:
keep accessory belt debris out of your crank seal.
It does that job quietly, repeatedly, and without drama.
What this plate actually prevents
On BMW N5x engines, a failed or wandering accessory belt can get pulled past the crank pulley and into the front main seal.
When that happens, things escalate quickly.
This plate blocks that path.
No software.
No sensors.
No heroics.
Just a physical barrier in exactly the right place.
How it works (the short, honest version)
- Creates a solid barrier in front of the crank seal
- Prevents belt fragments and debris from entering the seal area
- Maintains consistent clearance under load
- Centers concentrically on the crank hub — not “close enough”
It doesn’t fix oil leaks.
It doesn’t save neglected belts.
It simply removes one failure mode from the equation.
What’s included
- CNC-machined crank seal protection plate (billet aluminum)
- Correct installation hardware
- Loctite (because everyone forgets it at least once)
- Installation reference
Everything required. Nothing extra.
Fitment (clear and specific)
Compatible engine codes
- N51 / N52 / N53
- N54
- N55
- S55
If your setup is unusual, reach out — answering a question now beats a return later.
When this plate makes sense
This is the part most people actually care about.
This plate is a good idea if:
- The car sees hard use, track time, or sustained high RPM
- You’re already doing front-end service or addressing oil leaks
- You want belt failures to stay inconvenient instead of catastrophic
This plate is probably overkill if:
- The car is fully stock
- Belts, pulleys, engine mounts, and gaskets are inspected and replaced regularly
- You’re comfortable rolling the dice on edge cases
Most customers don’t replace a working setup.
They install this when uncertainty becomes annoying.
Why some owners end up switching
We don’t lead with comparisons — but patterns show up over time.
Some owners come to this plate after:
- Clearance issues with other guards
- Install fitment that felt overly sensitive
When people switch, it’s usually not because something failed —
it’s because they wanted less guesswork the second time around.
Built like a machine-shop part (because it is)
- Machined in Canada
- Tight tolerances
- No styling gimmicks
- Designed by someone who has to live with the result
This isn’t a flashy solution.
It’s the kind that quietly does its job and never asks for attention.
5 STAR CUSTOMER EXPERIENCE
5 STAR CUSTOMER EXPERIENCE
We want you to have the best shopping experience. Talk to us, we're here to help!
FREE SHIPPING
FREE SHIPPING
Free shipping over $99 in north America
More shipping info in the FAQ section at bottom of this page
Fitment
Fitment
Guaranteed Fit for
N51, N52, N53, N54, N55, and S55 engines
All BMW six cylinder engines from 2007 - 2014 and more
All 335i, 135i, 235i, 435i, 535i, Z4 35i, X5 35i
All 6 Cylinder after 2006: 328i, 528i, 135i, 325i,323i,
And more!
MONEY BACK GUARANTEE
MONEY BACK GUARANTEE
Enjoy 90 Day 100% Money back guarantee. Just send it back - no questions asked.
Install Video
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Protect your BMW
Shield your crank seal from rogue accessory belts. Our guard ensures that your engine remains free from potential belt-related damages to the crank seal.
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Standards
We don't have time to do the job twice, that's why we manufacture exclusively in Canada to ensure highest standards for the quality of our parts.
✓ Made by Journeyman Machinists
✓ Tested on our own cars
✓ Tight Tolerances
✓ Made in Canada
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✔️ Compatible with:
BMW Six-Cylinders (All Years 2007–2014 & Beyond)
From early N-series motors to later performance variants — we’ve got you covered:
N51, N52, N53 — the backbone of BMW’s smooth inline-six legacy
N54 — the original twin-turbo powerhouse
N55 — the high-torque successor
S55 — the motorsport-derived M-car performance engine.Vehicles this plate fits include (but are not limited to):
1 Series: 135i, 128i, 1M
3 Series: 328i, 325i, 323i, 335i (including xi)
2 Series: 235i, M2
4 Series: 435i, M4
5 Series: 528i, 535i
Z Series: Z4 35i
X Series: X5 35i🚀 Whether it’s an everyday driver, a performance-tuned build, or a track weapon — this protection plate adds peace of mind where it matters most.
Why bother getting the Crank Seal Guard?
Due to the placement of their accessory belt beneath common leak areas in the N5x oil and coolant system. If a leak occurs, the accessory belt may begin to displace from the crank pulley. The engine's design allows small rubber fragments from the deteriorating belt to pass through the crank seal easily. These belt shards can then enter the timing chain, valve cover, or oil pickup, causing damage or engine oil starvation.
Most common reasons for the serpentine belt to come off:
- Oil dripping from a leak of the Oil Filter housing
- Worn out engine mounts causing power steering pulley to get in contact with subframe
- Oil dripping from the oil cooler connection
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FREE SHIPPING IN NORTH AMERICA
Delivery is on us for all orders over $99
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FEEDING HUNGRY KIDS
With every purchase you help feeding hungry kids in British Columbia through Backpack Buddies
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5 STAR CUSTOMER EXPERIENCE
We want you to have the best shopping experience. Talk to us, we're here to help!
-
FREE SHIPPING IN EUROPE & DOWN UNDER
Delivery is on us for all orders over $160 in Europe, Australia, and New Zealand
Crank Seal Guard
FAQ
USA - SHIPPING
Enjoy Free Standard Shipping on all USA orders over $99 USD. The regular shipping rate is $7.95 USD.
USPS Priority 2-4 Business days is 15 USD.
Customized items are final sale.
Clearance items are final sale.
Make sure to double check your address before we ship. If your address is incorrect and the order is returned to us, a new shipping fee will be charged to deliver the order back to the correct address.
CANADA - SHIPPING
Enjoy Free Standard Shipping on all Canadian Orders over $99 USD.
The regular shipping rate is $7.95 USD.
2 day shipping is available with UPS Express® Saver 1-2 Days for $30 CAD.
Customized items are final sale.
Clearance items are final sale.
Make sure to double check your address before we ship. If your address is incorrect and the order is returned to us, a new shipping fee will be charged to deliver the order back to the correct address.
Europe / Australia / New Zealand - Shipping & Returns
Enjoy Free Standard Shipping on all European / Down-Under orders over $160 USD.
The regular shipping rate for Europe / Down-Under is $15 USD. It is shipped with Canada Post and It does not always come with a tracking number.
Can I perform the install myself?
We recommend you use a licensed mechanic to install the parts.
However, if you are mechanically inclined you will be able to install the parts yourself. There are plenty of install videos available to help with the install.
Corrosion
Will the zinc plated bolts in the Crank Seal Guard Kit cause corrosion on my engine block?
Yes. However, It will be very minimal.
Forum reviews suggest to opt for aluminum fasteners for N52, and N51 engines due to their magnesium content.
Where are your Products Designed and Manufactured?
We design and manufacture proudly in British Columbia, Canada!