BMR K-Member Vibration and a Fix

[NWBoss]

Thought to post this as it might help someone else, too.

I got a BMR K-member (Lowered Motor Mounts, Standard Rack Mounts), A-Arm (Adjustable, Delrin Bushings/Rod Ends, 19mm Tall Ball Joint), radiator support and chassis brace for my 2013 Boss. Researched them before placing the order and about 90% of the comments indicated that slightly increased vibration is expected. Some comments reported really bad vibration, so much that the BMR K-member was swapped out for the OEM part. Interesting. So is it slightly increased or really bad?

Parts were installed by a Ford certified technician. I test drove the car. Almost no increase in vibration at idle. So far so good. Up to 3K RPM no increase in vibration. After 3K RPM vibration was insane! The rearview mirror shook so bad that you could not tell the make or model of the cars driving behind you on the highway. Dashboard rattled like crazy. It felt as the dashboard would fall off any time. The vibration shook my whole body, I got dizzy and physically sick after a few minutes. Hmmm. So, I guess the vibration IS really bad and 90% of people are in denial. As this is statistically not likely, I called BMR. They suggested a few tests and modifications in the install.

BMR's suggestions:
0) Let's make sure that the vibration is coming from the motor mounts and not from the drive shaft or transmission. Park the car and rev through the entire RPM range. Watch the rear-view mirror if it shakes or not. The steering wheel should not shake. Then do the same while the car is in gear. If the vibration is coming from the motor mounts then it will be the same in both cases when the car is in park and when the car is in the gears.

1) Make sure that the oil pan is not touching the steering rack. If using the lowered motor mounts the gap between the oil pan and the rack becomes very narrow. The space might be only an 1/8th of an inch. They suggested to possibly use a spacer and raise the engine back a 1/4th of an inch.

2) Go under the car, reach up and grab the red motor mounts and try to twist them. If you can twist them then they need to be tightened. They should not move.

3) Many of their customers successfully tried to use a billet aluminum motor mount that eliminates any movement of the engine.
http://www.jpcracing.com/jpc-custom-billet-aluminum-motor-mount-inserts-for-bmr-k-member/
Although it is not indicated so on the web site but it fits the 2011+ K-member. It replaces the BMR motor mounts.

Did all 4 above. 0 and 2 checked. There was almost no gap between pan and rack. Technician used an aluminum spacer for the mounts and vibration is practically gone. On a zero to ten scale this is the level of vibration experienced if the vibration with OEM mounts is considered zero (non-existent):

Part: Level of Vibration
OEM mounts: 0
BMR poly mounts with rack and pan touching: 10
BMR poly mounts with spacer: 1
Solid aluminum mounts (with spacer or you have the pan and rack touching): 2

Again hope this helps someone out there.

 

[tirole]

I also had terrible vibration after installing 1/2 lowered K-member. It seems to be no clearance when I saw the clearance between rack and engine so I inserted three washer totally 4.3mm on top of the aluminium mount and then vibration was completely off.

I've bought the anti vibration engine bushing but no need to install because I can solve that problem by 3 washer for each.

The washers are extra washer of bmr K-member.

 

[NWBoss]

I also had terrible vibration after installing 1/2 lowered K-member. It seems to be no clearance when I saw the clearance between rack and engine so I inserted three washer totally 4.3mm on top of the aluminium mount and then vibration was completely off.

I've bought the anti vibration engine bushing but no need to install because I can solve that problem by 3 washer for each.

The washers are extra washer of bmr K-member.

Technician thought it was a design flaw on BMR's part. Or maybe manufacturing is off by a few mm. Because, really it is a few mm as you noted. I wonder how many of the bad experiences reported on the Internet are from guys who had the same easy to resolve problem but did not investigate it long enough to figure it out. Some are complaining of serious vibration while there is not much of an increase if it is installed right and with the spacers. It is barely noticable. I notice the slight increase in vibration only because I know that a new engine mount was installed that was supposed to increase vibration a little. I bet that nobody would notice even back to back if there was a few days of time gap between riding the car with OEM and then with BMR frame. On the other hand, the car feels so much tighter with the new engine mounts that it is very noticeable for the driver.