Couple weeks ago, picked up a new 06 MCS. have 1,494 miles on it now.
No mushrooming. (running 17" RFT's). Other day had a MINI shop look at
it and they confirmed no mushrooming. everything is still a flat plane.

figured I'd add a little insurance by installing the M7's.

They went on just fine, no wobble. Knowing that the nuts torque down
to 25 ft/lbs. I was very careful not to strip them.

Now my observations. Are the nuts supposed to be flush with the stud?
All mine are about 1 to 1 1/2 threads short of being flush. (I realize the ideal
is to have 2 threads sticking out on top of the nut).

All six nuts/studs are consistent.

Purchased my M7's from the MINI shop, but got no instructions with them.

just curious.

 

I installed my SRPs the night I brought the car home, with less than 15 miles on the clock, so I know that my towers hadn't had a chance to mushroom yet. Even so the studs are 1-2 threads down inside the nuts, just like yours.

I don't think it's a problem, though. The forces that would try to pull the studs down out of the nuts are fairly small. The big forces, the ones that cause the mushrooming in the first place, are from the strut pressing upwards, so those forces wouldn't tend to pull the studs out of the nuts.

Like you, I'd rather have a couple of threads poking up through the nuts, but I've never heard of a problem with the nuts coming loose after installing the M7 plates.

 

thanks for the prompt reply. I'll leave them on then.

 

Think about replacing these with nylock nuts.

 

Same here, just a couple of threads shy of coming through the nut. I have read in other threads however that this is not a big deal for these bolts since they are not in tension unless the wheel is off the ground. The amount of thread engagement is sufficient to prohibit mushrooming with the SRP in place.

 

Now there's a thought... thanks.

 

Are Nylock nuts available with different depths of nylon? All of the ones I've used in the past only have the nylon insert on the top two or three threads - the rest of the threads are bare metal.

Of course, it's the last few threads on the stock strut tower nuts that aren't engaging, so with the nylock nuts I've seen in the past, I'd reach the 25 lbf-ft of torque before the nut went down far enough on the stud to engage the nylon insert onto the stud.

 

Good point. I'm pretty certain that they do come in different profiles. I'll try and remember to check with my fastener guy and see if there is that magic size. i'll let ya know.

 

I used a different type of lock nut, the kind that is oval on the inside so that it holds onto the stud. I think they were for a Cadillac and have a integrated washer.

 

how do they check if theres mushrooming?? (without SRPs..)

 

I used a mild thread lock compound rather than aircraft or nylock nuts. You can, too.

 

wont help if the threads are below a regular nut !

I'll be interested to see different lock nuts
What do you call the nuts with the lock washer as part of the nut ?

 

Try what we call ''1/2 nylock nuts", think they're call reduced height nuts,similar in thickness as jam nuts.Bowman Products offers them,as i'm sure other companies do.Just my $0.02.

 

There are several threads on SRP's and the nut issue. Many opinions go in many directions. I figure, Set 'em and forget 'em. I installed mine with a little Loctite (mild, I think it is Loctite blue), a few months ago. Same thread deficit. My nuts haven't moved a bit (I need to get out more ) and no new 'schrooming. It's not the ideal solution but its cheap (relatively), easy insurance unless you're planning on doing the Baja.

 

The nuts on my m7 plates are not flush, either.

The standard nuts are a design called "flange nuts." They incorporate the flange below the hex portion and sometimes a "rachet" surface underneath. As I recall, the mini's standard nuts have a smooth surface on the bottom. The all-metal lock nuts referred to above routinely come in a flanged version.

Nylock jam nuts are available, but I seriously doubt if you can find any in a flange design. They certainly could be used with an appropriate washer.

Some nuts come with a captured washer, usually a star washer. The function of a star washer is to ensure electrial contact through the fastener, not as a locking device.

The bolts are not subject to any kind of shearing load that I can see - being stressed only in extention on spring rebound. On spring compression, they look like their only function is as a locating pin.

Note: (pet peeve) Split lock washers are just silly - they are a flat washer under very minor torque. It is the torque that makes the nut function. If you need a locking device, lock nuts (nylock, etc.) are vastly preferable, as is loctite. If you want to make sure a nut doesn't come off - safety wire it.

For the budding Berts among us, I refer to Carroll Smith's excellent book, "Nuts, Bolts, Fasteners and Plumbing Handbook." Is a collection of fasteners the same as a collection of paper clips?

DD

 

Preventing the nut from backing off is a non-issue, the critical point has been missed in this discussion; too few threads are depended upon. I know it is the first fully engaged thread that bears the greatest load, but if the thread count behind it is reduced, so then the back up is reduced also. I believe the risk (neither nut nor stud is exceptionally hardened) of plastic deformation will render the first thread useless after repeated torque applications and continues for each thread thereafter. This would not be important if the nut was expected to act as a place holder but this brace is expected to apply some “magical” clamping force and that is not possible, either with sufficient thread purchase by the little nut on the little stud with little torque or with less thread contact on a compromised stud.

If there is a belief the fastening system is only there to keep the guide support in place while the suspension is at extension; how can that piece of metal placed on top of the tower be trusted to prevent deformation at full compression with the same fastening system and design consideration?

 

One post has been removed from the thread. Going forward, feel free to discuss the topic, but it needs to be done with respect for the other members of the forum participating in the thread. We will start handing out infractions if that can't be done.

 

Actually if your look at the oem nuts that you buy new that they are ovalized near the top so it locks the nut. I noticed this when I did my install. My nuts are actually pretty close to flush. I marked the position and will check occasionally. The nuts are cheap from the dealer. Like 23 cents I think. Patrick MINI in Chicago had good prices and will give their version of a discount.

 

Don't know why. The use of the word magical in a previous post is tickling my funny bone.

from above, "...but the purchasers of this brace expect it to apply some “magical” clamping force and that is not possible,..."

 

maybe if we click our heels three times before we step in and fire it up, that'll help too....

I'm sticking with my M7's. We'll see what happen's.

 

Remember, with the Ireland Engineering fixed camber plates, they come with the nylon locking nuts, plus longer bolts which allow at least three threads to be seen with the nut on, and this is with the M7 STB.

 

I have a question. I've read several posts about "mushrooming" or strut tower deformation being a common occurrence yet after searching the NHSTA website I can't find a single complaint from any MINI owner to NHSTA. If "mushrooming" is such a common occurrence, why hasn't anyone registered a formal complaint with NHSTA? Something is not right; it doesn't add up.

According to the posts I've read BMW denies that it is a structural or a manufacturing defect and will not cover repairs under warranty. Yet others claim never to have abused their vehicles nor to have hit any unusual potholes, curbs, etc. I would expect that if MINIs are so prone to strut tower deformation that it seems to happen all on its own withoiut any unusual cause that owners would have registered complaints with NHSTA, yet there aren't any? Can anyone explain this?

Moreover, the posts about the method of repair describe beating on the top of the strut tower with a sledge hammer. That is hardly a reasonable repair in my judgment, certainly not what I would expect. Why wouldn't it just happen again?

I would appreciate any explanations. Thank you.

 

^^ what I wanted to ask too..

Also, let me ask again,



How do you figure that you have mushrooming?????? WITHOUT SRPs.

 

The studs that come up through the tower from the strut mount should be straight up. If the tower is mushroomed, the studs will be splayed at an angle.

 

sprp85, check out this thread, especially post #10 for some pics of a normal and mushroomed strut tower. Essentially the top of the strut tower should be pretty flat, but with driving over bad roads with low profile tires on larger wheels(17" or 18" for example) the impacts cause the top of the tower to deform.

Hope this helps.