Boot Strut Replacement DIY

[-Keith-]

Following on from my journal post where I replaced the failed boots struts on my car, here is an quick 'how to' to refer to if you need to do the same.

If your boot has started to drop like a stone when closing, then this is no doubt the problem. The boot is exceptionally heavy without working struts, due to the locking mechanism and heavy wiper motor being at the furthermost point out from the hinges.

You have two options. Either order some new OE boot struts from BMW (part number 51248399296), or get some custom item made up. The BMW OEM items were £55 for the pair.

I plumped for the latter, as some other members have reported that even the new OE items are still a bit poor - i.e. not damping the closure of the heavy hatch to avoid it slamming.

I ordered mine from SGS Engineering (http://www.sgs-engineering.com/shop/categories/search/gas-strut-products), who make struts in the correct size and spec for the M Coupe boot. These cost me £43 for the pair. The OEM struts are gassed to 280n, so I asked them to make me some up at 320n, which after fitting, I can report is about spot-on. The boot now requires you to push it down with a little force to close and lock in, whereas before it would close just by dropping it... Asking anyone else to close the boot for me usually meant a almighty slam, but at this pressure I'm pretty sure it will be able to cope without. :thumbsup:


Removal of Old Struts.

Simply get a small flathead and prize back the crescent clip from the ball joint at any end until one side pops out;

Et Voila
http://i848.photobucket.com/albums/ab46/ksoundwerx/IMG_0160.jpg


Once this has been removed you will be able to work the ball joint off from the mounting point.

Repeat all around, remove both struts and then clean up the ball mounts and dab a little grease onto them.


Mounting the SGS/OE Items

I found it best to 'loosen' the strust first by compressing the piston a number of times to loosen it up a little. This require a lot of weight and a firm grip. Be careful not to bend the shaft.

The SGS items have a crescent pin, which is rather self explanatory, it pops off the shaft, and can then be pulled out. Once out, locate the end onto the ball mount, reinsert and clip into place. Fitting the OE items will be the much the same.

http://i848.photobucket.com/albums/ab46/ksoundwerx/IMG_0158.jpg

I did the bottom first, and then had to employ the help of a friend to help me compress the shaft a touch so we could get the top onto the hatch ball mount. It is definitely advisable to employ the help of someone else to aid you at this part.

Repeat for the other side.

All fitted;http://i848.photobucket.com/albums/ab46/ksoundwerx/IMG_0157Struts.jpg

And there we are - simple as that.

Boot will perhaps feel a little stiff opening/closing at first, but it will become smoother as the pistons get used more.

I hope you have found this useful.

Keith

[-Keith-]

Oh, if any one thinks they may just have one failed boot strut as mine was, whip them off and check (simply by trying to compress it - a working item will push itself back out). If you have one which is still working OK and you do not wish to buy a pair, you can purchase my working OEM item from me for £15 delivered. :thumbsup:

['Yadi]

Thanks for taking the time to do the write up Keith.

[-Keith-]

No problem, I'm pleased to contribute to the Forum's resource for future reference.

[h4pry]

Thanks, Keith.

[kwoffa]

just ordered a pair(non oem) ready to fix my tail gate,along with fixing the heated screen,,just please stop raining at the w/ends!!!.Thanks Keith for all your paitence and time..

[-Keith-]

just ordered a pair(non oem) ready to fix my tail gate,along with fixing the heated screen,,just please stop raining at the w/ends!!!.Thanks Keith for all your paitence and time..
No problem at all mate. If we keep adding DIY's, this will become the No.1 resource for M Coupe enthusiast.

And of course, they are very useful to us... DIY's save money! :cheers2:

[Shunt]

Going from memory here, but I'm sure mine didn't open that far (wasn't because the stuts were knackered either), yours is almost verticle. Could be stressing the cabling unduly, were they made to be the same length as OEM when fully open?

[-Keith-]

Going from memory here, but I'm sure mine didn't open that far (wasn't because the stuts were knackered either), yours is almost verticle. Could be stressing the cabling unduly, were they made to be the same length as OEM when fully open?

Never thought about cable stress. Although the heated screen cables in mine were broken when I bought it (just fixed actually, see journal).

However, would you not agree that even 10 degrees further open, would translate to very little movement at the hinge, so I cant see there be much extra stress.

Anyhow, I can't remember how far my boot opened before these new ones were put in? Anyone have a picture of theirs wide open from a side on shot?

SGS knew the specification of the old struts, even down to what pressure they were gassed to, so I assume there measurements in strut length cannot be far different?

You have me wondering now!

[-Keith-]

Cheers Neil.

No I did not request the length - they had all the stats to hand. I simply listed my car model and the application, and that was it. Only thing I specified was ask them to pump up the pressure.

I'll tell you what, tomorrow I will get my old struts and a picture of them next to one another for comparison.

[kwoffa]

I ordered my struts on Wednesday and they wer delivered yesterday! fast or what! i thought the same regarding the higher opening,as i too thought Keiths lid was opened rather a lot higher than normal,however on checking the actual lengths i can confirm on arrival my struts wer not compressed and that they apear to be the exact same length,my boot lid is the same height as keiths on the original strut..i really dont think there is any problem...as the strutts are of the same length as OEM..cant wait to put them on! i also need to do the screen re-wire as it isnt working..did once! so i guess that there is no stress problems just shite wiring !

[-Keith-]

That's good to know Kwoffa. Cheers for the input mate.

[dave p]

Going from memory here, but I'm sure mine didn't open that far (wasn't because the stuts were knackered either), yours is almost verticle. Could be stressing the cabling unduly, were they made to be the same length as OEM when fully open?


mine has never opened to near vertical, more like this picture from the forum gallery


http://www.z3mcoupe.com/photopost/data//500/590black_and_white.jpg

[coupe fan]

mine has never opened to near vertical, more like this picture from the forum gallery


http://www.z3mcoupe.com/photopost/data//500/590black_and_white.jpg

That picture amazes me. Mine has never opened anywhere near to that extent. I'm going to try it tomorrow to find out just how far it will open and what the limiting factor is.

[Tig]

Hi,
I also bought a pair of boot struts from SGS. Well made BUT about 5mm too long when fitted. This caused the boot lid to be almost vertical when both fitted. This made the ABS tailgate spoiler to rub on the trailing edge of the roof. Didn't fancy any long term damage, so replaced one of the old struts back in place. So with one new and one old the lift was restricted to the correct height and angle, with the strength of the new one more than enough to hold the tailgate up, saving my head from further damage !!. Also it no longer needs the weight of 2 wrestlers to bring the tailgate down, as it did with both new struts fitted.
A more "engineering" fix would be to shorten one of the screw on ends of the new struts, which only needed 5 mm removed to make it work properly.
Struts are very well made and fitted easily. Definately recommended.

:hurray::conehead::smash:

[kwoffa]

update on struts...following closer inspection...i must stand corected...after looking closer,i was trying to do the refit quickly..i can confirm that the sgs struts are a tad longer!!! and i will be contacting sgs for an alternative ..sorry for anything misleading..

[ian]

The replacement are clearly too long.

I don't see why change from OEMs, unless saving the price of a couple of gallons of petrol is key.

[-Keith-]

The replacement are clearly too long.

I don't see why change from OEMs, unless saving the price of a couple of gallons of petrol is key.
I changed from OEMs as I had read a number of complaints that even new OE items were a little poor. That is it - no other reason. The fact they were cheaper was just a bonus.

Even if they are a little longer, like I said before, even 10 degrees difference equates to very little extra movement at the hinge, so it's not really an issue. The SGS items are also strong enough for you to leave the boot at any interim position, so if you don't wish to open it that far, you don't have to.

Either way, the point of this post was just to be a simple DIY, so that whichever option you choose, you have a quick guide to read.

[coupe fan]

This is the tailgate fully open with OEM struts. It is much higher than I thought it would be. Just past the parallel position with the aerial.

http://www.z3mcoupe.com/photopost/data//500/180SP_A0194.jpg

[kwoffa]

The idea of replacing with non oem struts is just choice,as with springs/brake pads/hoses etc...they all work!!! often parts are changed to non oem for differrent reasons for sure some are to improve performance some are purely cosmetic, choice thats all! However having looked yet again at the SGS struts it is possible to shorten the length of them and you are able to make them exactly the same length.just by undoing one of the chrome ends and cutting the FEMALE part shorter,the thread goes a long way in and will not weaken the attachment..the amount to take off is not that much but will make it the right length.

[kwoffa]

The idea of replacing with non oem struts is just choice,as with springs/brake pads/hoses etc...they all work!!! often parts are changed to non oem for differrent reasons for sure some are to improve performance some are purely cosmetic, choice thats all! However having looked yet again at the SGS struts it is possible to shorten the length of them and you are able to make them exactly the same length.just by undoing one of the chrome ends and cutting the FEMALE part shorter,the thread goes a long way in and will not weaken the attachment..the amount to take off is not that much but will make it the right length therefore there wont be any concerns about stretching the internal wiring/catching the spoiler etc..but you will have the benifit of a stronger lift etc...

[kwoffa]

I have phoned SGS and told them about the length of these struts,and,they are sending me 4 shorter chrome ends,so i would advise if anyone is thinking of ordering,just ask for the shorter ends which makes them a perfect fit!

[-Keith-]

I have phoned SGS and told them about the length of these struts,and,they are sending me 4 shorter chrome ends,so i would advise if anyone is thinking of ordering,just ask for the shorter ends which makes them a perfect fit!

Great, will do :thumbsup:

[Fat Tony]

I read this thread before buying my MC (haha, that sounds ace... my MC for a full 2 days now :thumbsup: )

Our driveway is really quite steep and the OE struts on the boot just can't carry the weight of the boot lid when parked at that angle. So I thought I'd have a look at getting some higher gassed SGS items as per Keith's recommendation

I fired off an email to them today making an initial enquiry and received the following reply offering forum member a discount on the parts. As you'll see, Andy also states that they can make the struts to whatever length if you have concerns about the boot opening too far

--------------------------
Thank you for your enquiry. What is the part number printed on the side of your gas strut? We can increase the force to 320N at no extra cost.

If you have the same struts as keith they are £15.10 each plus VAT and £6.30 carriage.

As you found us on the forum/from Keith’s post I am pleased to offer you 25% off the cost of the struts. This offer is open to all of your fellow forum member; all they need to do is call their order through and quote the forum name and their username.

The cost delivered for a pair, including VAT and carriage is £34.02 (normal delivered price £42.88)

If you get the chance to message/speak to Keith please thank him on my behalf for mentioning us in his write up. If he needs anything in the future (BMW or not) we can offer him 25% off list.

I notice from the thread that there are a few concerns about opening heights- if required, we can shorten gas struts or supply shorter end fixings. We manufacturer our own struts so we can offer any size/strength that you need.

If you have any questions or would like to place an order, please don’t hesitate to call.

Kind Regards

Andy Wyatt.

--------------------

I haven't ordered from them yet, but already impressed with their customer service :thumbsup:

[-Keith-]

Glad my thread was of help. They (SGS) were good guys to deal with and offered great service.

Back then though, being the first, I paid the full £42 for mine :lol:

[andrewturner]

Glad my thread was of help. They (SGS) were good guys to deal with and offered great service.

Back then though, being the first, I paid the full £42 for mine :lol:

Me too. Although I didnt mention Keith and did it all online.

Very good service IMO

[kwoffa]

Just remember to order the short chrome ends!they will then be the right length,

[Fat Tony]

:thumbsup: Well that's that little job done then.

Struts ordered from SGS on Wednesday afternoon, delivered by lunchtime on Thursday as promised by Andy at time of order (what Christmas backlog in the post?).

The struts are the same length as the OE items and came supplied with similar fittings to OE, rather than the chrome items mentioned in this thread.

Very simple job to fit and if it wasn't for Keith's heads-up on this simple fix I'd have lived with the nuisance of a boot lid that wouldn't stay up on our steep drive (and subsequent bruises no doubt). Uprated pressure is spot on.

Thanks again to Keith and Andy at SGS

[jrsmooth]

:thumbsup: Well that's that little job done then.

Struts ordered from SGS on Wednesday afternoon, delivered by lunchtime on Thursday as promised by Andy at time of order (what Christmas backlog in the post?).

The struts are the same length as the OE items and came supplied with similar fittings to OE, rather than the chrome items mentioned in this thread.

Very simple job to fit and if it wasn't for Keith's heads-up on this simple fix I'd have lived with the nuisance of a boot lid that wouldn't stay up on our steep drive (and subsequent bruises no doubt). Uprated pressure is spot on.

Thanks again to Keith and Andy at SGS

Tony, do you have a part number or an order number for the struts you ordered? I would rather have black as per the BMW struts than chrome!

Cheers,
Joe :thumbsup:

[Fat Tony]

Hey Joe, I didn't specify the OE type fittings mate, they just turned up that way

My email to Andy at SGS follows:
===============
> Thanks very much for the speedy reply and generous forum discount.
> I've copied your email in to that thread of Keith's so the rest of the
> members can find details there.
>
> The part number of the struts fitted to my car appear to be the same
> as Keith's: 51248399296
>
> With regards to the length, I'm happy to take whichever route you
> suggest, as long as the new struts are the same length as the OE items
> they're replacing.
================

My MC's an S50 if that makes a difference

[W1234]

Just ordered a pair (avoiding the VAT increase), will see how I get on.

Thanks to Keith and Tony for updating the thread. I think back in the day I found SGS in the first place (through google, trying to find a company that re-gasses struts!), so I'm glad to finally be making use of them myself!

[wefail]

Just changed these. I'd been putting it off because I thought compressing the struts to get them in place would be a PITA for me to do alone.

Not at all, 5 second job to take the old ones off and get these on.

No more attacks from the boot on my head!:cornut:

[W1234]

Just fitted these - no problems. The SGS struts now come with black fittings (very similar to the originals) and are precisely the correct length so they fit straight on i.e. it's an easy solo job.

I also increased the pressure to 320 as per Keith's OP. That seems spot on.

Thanks to Keith for the DIY and SGS for their excellent service.

[oo 1005]

I'm not sure if mine need replacing - when I park on a slope (outside my flat) the boot doesn't stay open but it is quite a slope... on leve ground they are fine though.. Does anyone else park on a fairly steep slope and have problems with the boot closing (nearly knocked my fiance out when the boot clouted her on Saturday!!)

[-Keith-]

Before one of mine failed, the boot was like you describe your to be - it would stay up, but a sharp gust of wind, or a by parking on a gradient it would fall shut.

I am certain you would no longer have it closing on the slope if you had some SGS struts made up with the slightly increased 320psi pressure :thumb:

[W1234]

Before one of mine failed, the boot was like you describe your to be - it would stay up, but a sharp gust of wind, or a by parking on a gradient it would fall shut.

I am certain you would no longer have it closing on the slope if you had some SGS struts made up with the slightly increased 320psi pressure :thumb:

Yep, agreed Keith.

SGS were great to deal with and it's a cheap and quick job, so I'd recommend doing it. It's clearly something that MCs will need at some point.

Mine never dropped on it's own, but it would shut rather quicker than I'd like in inexperienced hands. Cheaper to replace the struts than the rear window glass!

[dave p]

fitted a new pair today - latest type look as per original

http://oi56.tinypic.com/25rjzhu.jpg (http://oi56.tinypic.com/25rjzhu.jpg)