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

If I had to guess, and I'm guessing with very reputable knowledge here, the bolts are the direction that they are because of assembly issues identified during prototype builds, and it was an oversight that the threads were loaded in shear. The cradle subassembly (loaded pumpkin, all control members, knuckle/hub, swaybar) is almost certainly put together at an outside assembler and sent in to Flat Rock, and it could be an error.

One of the biggest parts of the VP (verification prototype) test plan are the durability units, half of which is chassis/structural and the other half powertrain. This failure mode would've shown up in the powertrain portion, assuming the exact same build configuration.

I just installed BK054. Am I correct in thinking this would not be an upgrade except for maybe NVH?

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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BK054 definitely improved shifting. It did not fix it completely but I'm hoping with an MGW and fluid change it will be where I want it.

BmacIL said:

Have you replaced the clutch spring with the Steeda one?

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I haven't and although I'm sure that'd help with pedal feel, the big problem is the rubbery driveline. It rocks so much with even the slightest timing or speed delta between engine and driveline. The only way to avoid the rock is to deliberately and delicately perform a perfect shift, which, is simply not realistic 98% of the time, hence the need for synchros

Actually, the only problem I have with the clutch pedal/feel is the vibration at high engine speeds. Shifter is absolutely perfect, I don't get all the fuss about it. Just need to calm down the driveline and that area will be good for me.

When is this kit available for purchase, Kelly? I'm ready now. Seriously.... can I buy a pre-production set?

EricSMG said:

I haven't and although I'm sure that'd help with pedal feel, the big problem is the rubbery driveline. It rocks so much with even the slightest timing or speed delta between engine and driveline. The only way to avoid the rock is deliberately and delicately perform a perfect shift, which, is simply not realistic 98% of the time.

Actually, the only problem I have with the clutch pedal/feel is the vibration at high engine speeds. Shifter is absolutely perfect, I don't get all the fuss about it. Just need to calm down the driveline and that area will be good for me.

When is this kit available for purchase, Kelly? I'm ready now.

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The spring helps immensely with feel, and because you can get the engagement point with precision, the frequency and severity that you notice driveline rubbery-ness is greatly diminished. Take out the stock one and drive it like that for a while (I put 20,000 miles on it with no spring without issue). My very first 1-2 shift after I took the spring out was butter smooth after about a month of trying to master the clutch setup stock, and not succeeding.

These should be available for order tomorrow on our website ;)

There it is!

http://www.bmrsuspension.com/index.cfm?page=products&productid=1713&superpro=0

Awesome Kelly!

Question - if you had to ball park, how much differential movement does this eliminate?

50%, 75%? Ball park figure

About 90-95% just driving.

During WOT, on an average car, approximately 75-80%

Hey Kelly, weren't some of the high horsepower guys upgrading the bolt too when using the BK050 billet diff bushings? I have a new iron diff housing that we're gonna put in the car this winter, and I thought I needed to upgrade the bolts that came in the BK050.....am I thinking right?!?

Bob

GForce uses our BK050 in their kits.

I informed them that there were bolt issues way back, when they were developing the kit.

So they ream our BK050 out and use 16mm hardware - since it is likely that the people using their 9" Kits will be making SERIOUS power.

That said, I have not seen any need to do that on my end...and I still run the hardware that comes with the BK050 in mine, and will continue to use the standard 14mm BK050 hardware even on the new combo which should be 300-400 more HP.

When you use the BK050, the bolts really do not see any significant loads due to the fact that the diff doesn't move - it is locked into place very solidly.

Hope that helps!

Would these fit a V6 auto? I'm on the fence between these and the aluminum version, any suggestions?

s550v6 said:

Would these fit a V6 auto? I'm on the fence between these and the aluminum version, any suggestions?

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They will work great for you, thanks for the order!

If you have any questions, let me know.

*Also - I dont think they have the instructions finished up, but it will be really similar to the BK054:

http://www.bmrsuspension.com/siteart/install/BK054.pdf

And just make sure you put those spacers inside the bushings, like the image I have attached. :cheers:

BMR Tech said:

They will work great for you, thanks for the order!

If you have any questions, let me know.

*Also - I dont think they have the instructions finished up, but it will be really similar to the BK054:

http://www.bmrsuspension.com/siteart/install/BK054.pdf

And just make sure you put those spacers inside the bushings, like the image I have attached. :cheers:

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Yessir! Would you say this is a simple install for the mechanically uninclined? I have you're "average joe" knowledge but have never dropped a cradle or anything before.

It's very simple IMO