I have recently totally rebuilt my struts using Koni reds, with everything new, from the coil springs to the bumpstops to the rubber spring pads, etc. I'm noticing the rubber on my strut mounts bulging and straining upwards. They haven't cracked yet but the caps are almost level with the top of the strut tower openings. After installing top strut plates and getting an alignment yesterday, I've noticed a faint clunk when I sometimes go over bumps. I rechecked the torque of the nut at the top of the strut and the three bolts of the strut mount, and everything is to spec. These are Lemforder mounts and have less than 50 miles on them. Are they just defective and I should replace with something like the ECS heavy duty mounts? Am I missing something? Perhaps the clunk is from something else like the end links, but I don't remember my old strut mounts ever bulging like this, even when the rubber cracked.

 

That looks very wrong….. did ya save the box. Curious about country of origin.

 

Looks like the rubber is perished on the guide Support / Strut Mount, Part Number: 31306778833

 

This should not happen in 50 miles, Lemfroder is a good quality brand.

Did you use lowering springs with the Koni's? I remember reading that these don't like those so maybe there is too little travel and you are bottoming out resulting in the top mounts taking the blow?

 

Stock height springs and I don't think I have the box anymore. Will check for markings when I change them, as these definitely seem like they'll need to come off. For whatever it's worth, I thought the paint/rubber looked a little funny out of the box, but at that point just assumed it would be a cosmetic issue only...

 

After putting the car up on jackstands, the paint/rubber still looks bad but the bulge has gone away. Sure seems like the rubber is bad or too flexible and not properly supporting the weight of the car's front end. I've ordered the ECS "heavy duty" mounts so we'll see how those work.

 

i'd love to hear your review on the ECS mounts. i ultimately decided to get adjustable camber plates because the OEM design is destined to fail.

 

I just installed them a month ago. These ECS plates they fit well. I like it.

 

I just finished installing the ECS mounts. Initial impression is positive, they're nicely packaged and seem to be higher quality than the Lemforder alternative.




The bearing felt smoother and appears sealed unlike Lemforders, and I elected to leave off the little sealing washer since it didn't sit right with bottom of the already sealed bearing.



Things were looking great until I got the car back on the ground. The new mounts are now bulging almost as bad as the previous set.



So that brings me back to where I started and has me thinking this isn't an issue of the mounts being defective. Again, everything is torqued to spec, new bumpstops, Koni struts, etc. When I started this whole suspension refresh, I found some concerning rust on my rear coil springs. With those NLA from MINI, I ordered Lesjofors from FCP Euro. Since I was replacing the rears, I figured I'd also do the front springs. Before installing, I measured and found the dimensions of the old and new springs to match, including the diameter of the metal making up the coil. However, now that I have two prematurely and strangely worn sets of strut mounts, I'm thinking maybe the Lesjofors springs are not a proper replacement and I should swap the originals in. What do you think?

 

I’m not sure I follow how springs would have any effect on your strut mounts. I think that’s what you’re implying?

 

Yes. Kind of grasping at straws here... I'm wondering if those new springs might be too soft since the center of the mount is bulging up like from the strut rod. My old struts were totally blown and the bumpstops cracked, yet the mounts weren't doing this. I don't know why new Konis or bump stops would cause this, and it happened as soon the car had weight on wheels again. So process of elimination has me looking at the new aftermarket (but matching dimensions) springs.

Or might the Koni red struts have a different torque spec for the strut nut compared to the original MINI struts? I've been using the ~47 lb/ft from the MINI spec.

 

Well I found the paper I apparently overlooked that came with the Koni struts. I assume the nyloc bolt is one of the 59 lb/ft rows for the M14 on this chart.

 

I really doubt 12 ft lbs difference would cause your mounts to fail just from setting the car on the ground. The entire weight of the front end should be contacting the center race of each bearing, and if your springs were soft, it would just mean that the front end would sit too low.

I’m confused.

You still have the other washer on top of the spring hats, right? I seem to remember there being two washers per side, but it’s been a while since I looked at one of these.

Edit: I guess it’s actually a dust cover and a washer per side and not two washers.

 

I do have the washers in the stack, but left out the dust covers this time since they didn't really fit with the ECS mounts. I just tried to torque the strut nut down further and the hex of the strut rod stripped. So I guess I'm pretty stuck with where they currently are.

 

See realoem pic


Part #7 is the upper spring cup. #4 is the upper mount that you are in trouble with. Where are #5, and #6? They are needed to keep the strut from coming thru the mount. They are not evident to me on the Koni pic.

 

#6 is installed per the diagram. #5 is NOT currently installed, as it doesn't fit with the ECS mounts and their bearings are sealed already. In my previous attempt with the Lemforder mounts, I installed both 5 and 6, per the diagram. Same result with the bulging mounts both times.

 

Okay, that’s what I figured. I suspected that if you hadn’t installed the washer that the mounts wouldn’t spin properly on the struts, and you would have noticed.

Bummer about the stripped threads.

I suppose it’s highly unlikely to get two sets of bad mounts from two different manufacturers consecutively, but it’s technically not impossible. Just highly improbable.

I’m struggling to come up with another explanation.

 

Agreed, and thanks for the input anyway. I don't think there is anything else wrong or different that I could've done, besides the higher Koni torque spec. And I agree with you that 12 lbs probably wouldn't make the difference. Not to mention, so many people install the strut nut with an impact and don't measure the torque, yet they don't have this issue... I'm thinking of letting my mechanic have a go at assembling, as I've spent more than enough time around spring compressors lately, and maybe they'll get a different result.

 

I agree; I have a suspicion it isn’t an assembly issue. From what I recall, it should be pretty hard to mess things up in such a way to cause what you’re seeing. And yeah, I actually finished tightening mine with an impact. I tightened it by hand to where the shaft wouldn’t spin easily and smoke the seals, and then I banged the nut on the rest of the way because Koni yellows don’t really have a great way of both holding the shaft stationary and tightening the nut.

Ah, I just realized that you meant that the part you hold the shaft with stripped, not the threads. That makes more sense.

 

The below thread is about Koni Yellows, but it has some notes about using a dremel on washers. Maybe that would help?

do you have / can you get any pics of how yours is assembled?

https://www.northamericanmotoring.co...-to-giude.html

 

I’m pretty sure that shouldn’t matter for the reds. The yellows are adjustable, and as a result the rears have an oversized shaft, which necessitates drilling out the upper spring plate. I can’t believe anyone would use a dremel for that…

 

did you do a side-by-side comparison of the mounts you removed and the mounts you installed? and how long did you have them on before they began to bulge? i'm trying to follow along with the timeline...

 

I would be interested in seeing a picture of the entire strut. To get a bulge like that when the car is on the ground means something is pressing up from below. (or you have an elephant sitting on your hood) Since you got it twice with different mounts I'm inclined to think it has to do with the strut assembly.

Not saying you did anything wrong but maybe one of the strut parts isn't right?

 

Here are some more photos from the previous installs.

Newly built struts, plus one of each from the old set that I disassembled so I could be sure I was copying the reassembly of the new parts correctly:



On the car for the first time:



New ECS mount on the left, Lemforder mount that bulged with the first install on the right:



Timeline clarification as requested:

• I purchased the car and all the struts were blown, some of the bumpstops cracked, one of the strut mounts cracked, one of the rear springs had an area of nasty rust.
• Last month I built the new strut assemblies with Koni Special Actives, Lemforder mounts, and all new other parts as previously described.
• Immediately after that suspension work, it went to my mechanic for a while getting a new clutch and other work done.
• Last week I got it back from the shop, hammered down the slightly mushroomed strut towers, installed reinforcement plates over the towers, brought it back to the shop for an alignment.
• I then realized how bad the strut mounts looked and ordered the ECS heavy duty mounts as a replacement. There was less than 50 miles on the Lemforder mounts and Koni struts at this point - essentially just driving to and from my shop, plus the mechanic test driving after the clutch replacement.
• Yesterday I installed the new ECS mounts. They immediately strained up when I lowered the car back on the ground, although not bulging up as bad as the previous Lemforder mounts looked.
• Today I just did a 50 mile, mostly highway drive. The ECS mounts now look just like the Lemforders did before removal, bulging up with the dust caps almost level with the opening of the strut towers. The car handled fine and felt normal over bumps at highway speed. Below 20mph, I think small bumps sound a little funny, like a faint popping or creaking like you'd expect when a strut mount is starting to fail.
• I should note that the original strut mounts that were on the car when I bought it were not bulged up, just one with the standard crack they all eventually suffer from. Both pairs of new mounts haven't actually cracked yet but the paint or whatever coating is on the rubber looks crackly and is flaking off as the rubber strains upward.

 

I installed new TRQ front struts about a year ago. They have been holding up quite strong and with no cracks or anything wrong with them! I recommend them.