BMR Suspension's BK051 POLY Diff Lockout Kit: Close-Up Look, Pics and Info!

BMR Tech said:

haha yes.

I actually have a few people using these rear bolts with stock bushings.

Cant go wrong!

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So I thought my delrin kit had sleeves, I may be wrong. If it has sleeves a larger bolt would be a pain. If there are no sleeves, would I just drill out the Delrin?

Are your bolts upgraded on the full bushing kits?

Competition Orange said:

Are your bolts upgraded on the full bushing kits?

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I wondered this too, but the solid aluminum bushings have the 10.9 hardware. I asked him if he had ever seen a diff bolt shear with the solid aluminum bushing set-up and he said no. I've been giving the solid aluminum set-up hell and have not sheared anything.

This kit looks perfect, great job Kelly.

Competition Orange said:

Are your bolts upgraded on the full bushing kits?

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The Poly (BK049) yes.

The Billet Aluminum (BK050) no.

The solid (Billet) bushings eliminate the excessive loads being placed on the bolts, so they are not needed.

I am very interested in this as I find the stock diff bushings to be way, way too soft. I'm convinced they're the primary reason for the elusive smooth 1-2-3 shifts in the city in addition to various other characteristics that don't flatter a sporting car.

Kelly -

First, the basic kit comes with 10.9 'stock style' hardware which requires no modification for install, correct? It's only the included 12.9 allen upgraded hardware that, if one chooses to install, requires modification, correct?

Second, as for NVH. Totally stock car. I'm assuming that the additional NVH will be strictly gear whine, and, will only be noticeable with the windows up and stereo very low. Is this a fair assessment?

Speaking from experience with '14 track pack, once your ears hear the gear whine you will always hear the gear whine. Booming exhaust, thumping stereo, windows up or down, it will be there whispering sweet nothings in your ear. Your passengers may not hear it unless you point it out, and then they too will always hear it.

I emailed you Kelly. I'll be placing an order based on your reply. Thanks!

Do these fit the v6 as well??

Yes, they will fit a V6 ;)

Here is the correct product image for this kit.

EricSMG said:

I am very interested in this as I find the stock diff bushings to be way, way too soft. I'm convinced they're the primary reason for the elusive smooth 1-2-3 shifts in the city in addition to various other characteristics that don't flatter a sporting car.

Kelly -

First, the basic kit comes with 10.9 'stock style' hardware which requires no modification for install, correct? It's only the included 12.9 allen upgraded hardware that, if one chooses to install, requires modification, correct?

Second, as for NVH. Totally stock car. I'm assuming that the additional NVH will be strictly gear whine, and, will only be noticeable with the windows up and stereo very low. Is this a fair assessment?

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Have you replaced the clutch spring with the Steeda one?

[MENTION=9985]BMR Tech[/MENTION] - what makes the BK051 different from BMR's other differential solutions?

I apologize if you mentioned it and I didn't see it.

Bluemustang said:

@BMR Tech - what makes the BK051 different from BMR's other differential solutions?

I apologize if you mentioned it and I didn't see it.

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BK049: Poly Bushings

-Permanent mod. Replaces entire stock bushing with Poly. This was designed primarily for the street/strip guy who does not mind much NVH.

BK050: Solid Billet Bushings

-Best Diff solution on the market. Permanent mod. Strengthens the entire diff system, prevents bolt and diff failure, and does not allow any diff movement. NVH levels for this are high. This is for racecars, or streetcars that are driven by people who do not care about NVH increase.

BK054: Billet Lockout

- Bolt-on solution, removable. Performs better than this BK051...but provides significantly higher NVH levels. This kit is designed for street/strip and handling applications.

BK051: Poly Diff Lockout Kit

- Bolt-on solution, removable. Performs much better than stock bushings...but provides slightly increased NVH levels. This kit is designed for street, strip and handling applications as well, and is specifically meant for those who want the best diff mounting solution possible with the lowest NVH gains.


That said, ALL diff solutions on the market WILL increase NVH. There is no way around it.

So Ford designed this with the THREADS in shear??? What the hell engineering school did they go to?

How common is it for bolts to be loaded this way?

Does this kit move the load away from the threads with longer shanks?

Ugly John said:

So Ford designed this with the THREADS in shear??? What the hell engineering school did they go to?

How common is it for bolts to be loaded this way?

Does this kit move the load away from the threads with longer shanks?

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Correct - Ford designed the S550 Differential to Subframe mounts with the shear ON THE THREADS.

This has caused quite the issue for a few people, even with stock systems.

I do not quite understand how this design made it through, but it did. The proper method would have been for them to "through bolt" the system, to place the shear on the bolt shanks.

Thing is, it is actually advised against in the engineering world (placing shear on threads) - really makes you wonder.

As for our kit, this BK051 kit comes standard with Grade 10.9 hardware. The base hardware does place the shear on the threads. This has proven to hold up well for "most" applications.

We do provide the rear upgrade bolts in the kit, for those who are more serious about their modding and power levels. We have seen that keeping the rear bolts from failing, has led to much better durability and we have not yet seen an issue with the front bolts being damaged, when the rear bolts are strengthened and mounted with the thicker shank being on the shear path.