In other previous cars, pressing the trunk release button caused the trunk lid to pop open & lift up all by itself (wide open), either via springs or gas struts.
But this 2011 M56 trunk lid does not lift. In fact, it's difficult to tell that it popped open, at all, because the lid stays down (seemingly closed).
I had to manually lift the trunk lid (by hand) to check whether it did release. Is this normal?

If not normal, then how to fix it? Could it be as simple as replacing gas struts or metal springs?
If is normal (which I doubt), then is it possible to make it happen, via DIY mod?

This is normal.

Mine works just as you describe yours working. I stumbled across THIS GUY who was/is making a kit that pops the trunk open on older M's and Q's. No idea what it consists of but it may work for the Y51 M's as well.

works the same way for me

Debonair wrote:Mine works just as you describe yours working. I stumbled across THIS GUY who was/is making a kit that pops the trunk open on older M's and Q's. No idea what it consists of but it may work for the Y51 M's as well.

The "kit" consists of 2 trunk struts. That's it. The serial/product numbers are scratched off when you get them so you don't know what they are. I bought them from Jason about 8 years ago. They do work and pop the trunk all the way open, but for 160 bucks I would not do it again. You could probably call a company that makes trunk struts and find out what works for you.

Not trying to ruin the guys business but he's been getting bad reviews on several forums. I would use caution if you decide to deal with him.

reggiebrown40 wrote:

Debonair wrote:Mine works just as you describe yours working. I stumbled across THIS GUY who was/is making a kit that pops the trunk open on older M's and Q's. No idea what it consists of but it may work for the Y51 M's as well.

The "kit" consists of 2 trunk struts. That's it. The serial/product numbers are scratched off when you get them so you don't know what they are. I bought them from Jason about 8 years ago. They do work and pop the trunk all the way open, but for 160 bucks I would not do it again. You could probably call a company that makes trunk struts and find out what works for you.

Not trying to ruin the guys business but he's been getting bad reviews on several forums. I would use caution if you decide to deal with him.

Thanks for the info. Good to know what is actually is included. I may have to take some measurements and locate some slightly strong struts.

I have seen similar "kits" online. They are simply factory matching struts that have higher force. "this guy" didn't invent anything and did not change anything on these parts he sells. He probably scratches off any ID numbers, etc to prevent you from finding out he buys them online at a low price, scratches off the info, and sells them to you for 2X his price. I have no issue with having to lift the boot. I actually fancy how it closes itself soon as it gets near closed and you let it fall. Not too hard, but hard enough to latch.

Larz wrote:I actually fancy how it closes itself soon as it gets near closed and you let it fall. Not too hard, but hard enough to latch.

The auto-cinch is only on the 13+ models.

I agree Larz. I mean, if you actually have a product to sell I can understand you charging for it. I think the whole reason we have a community is to exchange ideas, free of charge.

If he stumbled onto struts that had more power he should share what he found instead of trying to sell it. Don't scratch off the serial numbers and sell them to a community you're a part of. Just imagine if everyone did BS like that? This forum would suck. I've gotten inspiration from Debonair, Majestic and advice from Ilya, and I've given advice, good or not is not the question. I just tried to help when asked.

This other thread is for an older 2003 M45, but that doesn't look anything like the trunk struts on my 2011 M56.
I'll have to remove the parts from the car, and maybe measure the lid weight with a scale?
I'm not sure how else to get the proper lifting force for new gas-struts, rather than assume 80# happens to work on my car.
Any ideas on guessing lifting force?

ibc wrote:This other thread is for an older 2003 M45, but that doesn't look anything like the trunk struts on my 2011 M56.
I'll have to remove the parts from the car, and maybe measure the lid weight with a scale?
I'm not sure how else to get the proper lifting force for new gas-struts, rather than assume 80# happens to work on my car.
Any ideas on guessing lifting force?

Take a look at the existing struts and see if there are any markings on it. It may have a number on it followed by a capital letter "N". If you find a part number (they may be from Stabilus - if so, their web site may have the info).

If there is a number with an "N" after it, this may be the strut force in Newtons ... a conversion to lbs will give you the correct value for the struts to get from the link I mention in the other thread. If this calculated number is approximately around 290 Newtons (65 lbs), this could be the right value.

For the length, extension and stroke dimensions, I do not know those for your model year ... does the service manual (see link in my sig) mention them? If not, you may have to do some measuring and estimation.

I plan to replace the front hood struts on my car sometime with these Nitrogen filled struts - these are far easier to replace since both ends of the struts are easily accessible fortunately!

Also, folks, regular cleaning and re-greasing of the hood hinges is highly recommended! If the hinge gets tight, it has a tendency to not "fold" properly and then the weight of the hood going down causes the hood to bend - permanently - and the hinge can get broken/stressed! Not a pretty sight apparently!

Z

Forgot to mention: weighing the lid is not going to help ... the strut operates an angle to the lid, so the force needed to raise the lid (as it turns, the force needed changes too) is not linearly related to the weight of the lid.

Yes, szh, sadly I discovered that. I removed the gas-struts, took lots of measurements & photos.
These existing gas-struts have no strength to lift the trunk lid, but can hold it steady, in any height position.
When I pop the trunk, it barely opens, say about 1/4 inch.

Weight of trunk lid alone (resting on a bathroom scale) supported only by hinges, but without any gas-struts: 20 lbs
That's surprisingly low!

Existing gas-struts:

Manufacturer: Stabilus
Labels: "015273 0460N 124/10 A33" and "84430-1MA0A"
Rod diameter: 8 mm
Tube diameter: 18 mm (3/4")
Extended length (between mounting point centers): 29 cm (11 3/8")
Stroke: 9 cm (3.5")
Initial/Maximum Force: 105 lbs / 110 lbs (ie, 460 Newtons)
Plastic sockets on both ends mount onto ball size: 10 mm

So I think stronger struts might be enough to lift the lid?

84430-1MA0A is the Nissan/Infiniti part number, FYI.

Debonair wrote:

Larz wrote:I actually fancy how it closes itself soon as it gets near closed and you let it fall. Not too hard, but hard enough to latch.

The auto-cinch is only on the 13+ models.

I was not referring to any sort of auto closing mechanism. I was referring the way the boot lid drops after it is pulled far enough to drop under it's own weight. It does not slam shut, but drops onto the latch with just enough force to cause it to lock.

ibc wrote:Weight of trunk lid alone (resting on a bathroom scale) supported only by hinges, but without any gas-struts: 20 lbs
That's surprisingly low![/quote
Indeed, yes!

ibc wrote:Existing gas-struts:

Manufacturer: Stabilus
Labels: "015273 0460N 124/10 A33" and "84430-1MA0A"
Rod diameter: 8 mm
Tube diameter: 18 mm (3/4")
Extended length (between mounting point centers): 29 cm (11 3/8")
Stroke: 9 cm (3.5")
Initial/Maximum Force: 105 lbs / 110 lbs (ie, 460 Newtons)
Plastic sockets on both ends mount onto ball size: 10 mm

So I think stronger struts might be enough to lift the lid?

Yes, but I would not make the force too large - you may have difficulty closing the lid and also bend it if the strut puts too much pressure on the lid when it is closed.

Meaning, largest I would consider in your case is a 120 lb or 125 lb strut, and that may be a bit much too. It is entirely possible that new 110 lb struts may work well too - not opening all the way, but enough to avoid the relatch problem perhaps.

On my car, the trunk opens all the way (with stock 65 lb struts changed to 80 lb replacements) and I am not entirely sure that this is a good thing. At one of my work locations, I had a co-worker come in and tell me that she had closed my trunk cause she saw it open! Had to do with my sitting down at my desk - close enough to the window and the car - and having the trunk open without my knowledge, cause the fob was in my trousers pocket and the trunk switch got pressed by keys.

Z

By the way, as a SWAG, these may be the ones that work well for you: http://www.asraymond.com/gas-struts.htm ... nit=metric - the dimensions are almost what you measured - with a stroke of 4". Only the extended length and stroke (longer stroke than stock is safest ... to avoid bending your lid) really matter to be honest, since the rod and tube diameter just have to be close enough (which they are), and the force is 118 lbs or 560 Newtons. The next one up is too strong at 146 lbs (same dimensions though).

But, please do your own research too!

These are $30 each (from one to four quantities) and drop down to $15.69 each if you buy five to nine.

The price seems to have gone up a bit since I last bought them (spdhardware does not seem to have their own web site anymore apparently?). Struts for my car trunk are now the same $30 each in quantities of four or less, and $15.xx each in quantities of five to nine.

I paid $15.85 each for two (a total of $45.73 including shipping and tax) when I bought them some few years ago.

Z

Don't you think this would be better?: http://www.asraymond.com/gas-struts.htm ... nit=metric

ibc wrote:Don't you think this would be better?: http://www.asraymond.com/gas-struts.htm ... nit=metric

Hmmm ... possibly. But I'd be concerned about two things:

1. The extended length is a bit more than what you measured from the existing struts. Yes, the difference is only 0.5", but this could force your trunk lid into opening farther than it should. I'd suggest to look at your hinge and car to see what might happen if the strut extends another 0.5" and the lid opens farther, or puts additional stress on the hinge ...

2. Secondly, I'd be quite a bit concerned about the 150lb force on each strut - this is a lot more than the stock 110 that you saw on the existing strut, I think. Yes, this will definitely open the trunk all the way! But it may put more stress on the lid than you might want and may also make it difficult to close, or bend the lid at the strut mount point when you push it down.

On my car, I think I would be perfectly happy with the trunk lid just popping up a bit, without opening all the way. But, this is certainly something that others might want, of course!

So, I dunno the right answer!

Z

Also, you may want to measure the Base Cylinder Length on your existing strut (see diagram at the links) - the one you noted is 3/4" longer than the one I linked. You would need to make sure that either fits into your car where the strut is located, when the lid is closed!

Z

Base Cylinder Length = 26 cm (10 1/4")
Yeah, I certainly don't want to bend the lid. Fitting it into place seems easily doable, without any obstruction from the hinges.
Photos: http://imgur.com/a/GBpM9

ibc wrote:Base Cylinder Length = 26 cm (10 1/4")
Yeah, I certainly don't want to bend the lid. Fitting it into place seems easily doable, without any obstruction from the hinges.
Photos: http://imgur.com/a/GBpM9

Man! Super easy access to both ends of the strut - I am jealous!

Given the prices are so low compared to OEM, you might consider ordering a set of both (does add $30 to the cost) and seeing which model suits your need perhaps? You might call the folks before you order, and see if they will take a return on the set you don't end up using use ... then you are only out the return shipping cost.

Also, based on your pictures, I think the 11.2" strut will be safer than the 11.8" ... if you really want more than the 118 lbs, there is a 146lb version of the same one I linked to.

Z

Did you figure out which ones to get?

Z

Nah. Not home. To busy having fun on vacation.

ibc wrote:To busy having fun on vacation.

Z