Closing roof thumps down

J

JayUK

Member
 Cardiff
Hi all,

So first question with this Z4.
Opening / Closing the roof there's a ratchety noise which I assume it's unlocking something?

But more concerning is when closing the roof it thumps down pretty hard the last couple of inches. The previous '04 one was much smoother delivery.
Issue or nothing to worry about?
 
Mine does not make any ratchety noises and I would say mine slams, but it isn't gentle either.

How laboured does the motor sound while its closing? If the motor has been moved to the boot, how upright is it? If its not completely upright check the oil levels in the reservoir at the top of it as it might be bringing air into the system occasionally.
 
For what it's worth, the roof on my previous Z4 (2007 - so a facelifted one) came down with a bit of a crash, whereas my new Z4 (2004) is much more gentle.

So could it be a post-facelift 'enhancement'?
 
Min doesn't slam, but there is a fairly hefty clunk. The roof seems to just drop the last 2-3 inches before the locks engage. Mine is also a 2007 so perhaps it is an "enhancement" :wink: as you say daimler3996
 
Mine certainly doesn't drop or make a ratchety noise. I pretty much always put my hand up to ease it down the last few inches onto the catch though. I have been doing that for 10 years without much changing. If I don't, then it kind of flops down and bounces about a tiny bit, without actually hitting the top of the screen. Which never looked particularly mechanically sympathetic to me. Hence the helping hand. :)

A quick video might help your cause. :wink:
 
There’s a tension cable in the roof between the outer canvas and the inner lining that controls/prevents this slamming you describe.
I’m told that it is adjustable but I’m not sure how you get to it

If it’s slamming, then the cable has stretched and needs adjusting back a centimetre or so
 
Number5 said:
There’s a tension cable in the roof between the outer canvas and the inner lining that controls/prevents this slamming you describe.
I’m told that it is adjustable but I’m not sure how you get to it

If it’s slamming, then the cable has stretched and needs adjusting back a centimetre or so
Click to expand...

Interesting never knew about this cable. Quick search in TIS gives this (limited) information. Is this the one you are talking about Number5?

Capture.PNG
 
Number5 said:
There’s a tension cable in the roof between the outer canvas and the inner lining that controls/prevents this slamming you describe.
I’m told that it is adjustable but I’m not sure how you get to it

If it’s slamming, then the cable has stretched and needs adjusting back a centimetre or so
Click to expand...

That sounds spot on!
Thanks TheDan as well, might have to get that looked at.
It's going to go to you Number5 soon when I can arrange it and get the roof motor done anyway, but will get that tension cable checked some time as well.
 
I think part #54347184482 tension belts could be the problem. I guess they stretch out over time. I bought a pair at ECS tuning, but never installed them. I don't think the install is complicated? I just help the top out the last couple inches so it doesn't slam. It doesn't look like what is in previous posts, they are elastic straps. Hope this helps, always liked this forum.
 
With that information, I found a previous post about the very issue!
https://z4-forum.com/forum/viewtopic.php?t=85491

Thanks all. They look a sod to fit!
 
Interesting that the guy that fixed his on zpost.com said :
"- The elastic straps are an install-only deal. They aren't already on the car and worn out, meaning you aren't "replacing" anything"
It seems E85's maybe never had them in the first place.

This is a copy of his link for the installation :
https://www.zpost.com/forums/attachment.php?attachmentid=935057&d=1383267111 and DIY guide https://www.zpost.com/forums/showthread.php?p=19780501#post19780501

So, it looks like the roof has belts and a cable for tension, but it can be tightened up with the use of BMW after-market elastic straps. Am I correct ?
 
As I've obviously got too much time on my hands, I've now decided that my roof does indeed close harder than I would like it to.

[vimeo]581770241[/vimeo]


To answer my own question above : yes, me, you are correct. :)

So I think the options to make the roof close smoother are:
1. Use your hand to gently lower the roof the last inch or so, or
2. Buy two elastic straps ( BMW 54-34-7-184-482 ) and install them, or
3. Try to locate and slightly shorten the tension cable (TIS 54 34 210)

Has anyone here done option 3 ?
 
Been for a rummage inside my roof to try to find the infamous tension cable.
I found a wire/cable on either side where I thought I might find the tension cable, but it seems quite thin and covered with insulation. I'm obviously concerned about fiddling too much with this at the moment, just in case it is not the tension cable and that it may be a sensor wire.

Have any experts been in there and know if this is indeed the tension cable, or something else ?
Photos 2 and 3 show where it seems to terminate at the lower rear. I think I can feel where it terminates at the top front, but I'm not too sure yet.
 

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If that is the tension cable, then I'm wondering if there may be a more simple way to shorten it ( e.g. by looping it round something ) rather than pulling the roof fabric off as per the TIS procedure above.
 
Having mulled it over, I don't think I would want to shorten that cable (assuming it is the tension cable), as it seems just too thin to be able to take repeated straining. Also, if BMW went to the trouble of designing the elastic straps to overcome the problem, there must have been a reason for them not just modifying the tension cables.

So, I think I will go about buying and fitting a pair of elastic straps (54347184482) .

By the way, to try to clarify, inside the hood are two "Tension Belts" which are obviously made from seat-belt material. They run from the rear of the roof, over the roof hoop which is above the rear window and to the the top thick (main) roof hoop. These are NOT the Elastic Straps but, confusingly, many suppliers (including BMW) are listing the "Elastic Straps" as "Tension Belts". The Elastic Straps are retrofitted to run in parallel with the Tension Belts and run from the roof hoop above the rear window to the the front edge of the top thick (main) roof hoop . To futher confuse, BMW also call the Elastic Straps, "Rubber Straps".


To try to keep the info in one place, here is the Bulletin copied from the zpost.com thread:

SI B54 14 07
Special Roofs

November 2007
Technical Service

SUBJECT
Soft Top Slams Down on the Cowl when Closing

MODEL
E85 (Z4 Roadster)

SITUATION
When the soft top is being closed, the front section of it slams down on the cowl.

CAUSE
Toward the end of its travel, the soft top is moving too quickly.

CORRECTION
Install 2 elastic straps to the soft top frame.

These elastic straps run from the rear bow (just above the rear window) to the main bow (in the middle of the closed soft top)

Each strap is secured to each side of the rear bow using the same fastening hole as the tension strap, and secures to the main bow using the outermost headliner fastening point.

PROCEDURE

Install 2 elastic straps per repair instruction RA 54 34 217.

NOTES:
^ It may be helpful to remove the soft top canvas cover, but this is not necessary for the repair.

^ It is necessary to remove the front half of the headliner. This also allows for the necessary access to feed the elastic strap from the rear bow to the main bow.

PARTS INFORMATION

Part Number Description Quantity
54 34 7 184 482 Elastic Strap 2

WARRANTY INFORMATION

Covered under the terms of the BMW New Vehicle Limited Warranty.

Please refer to the latest KSD for all applicable labor operations and allowances.

If the appropriate labor operation is not contained in KSD, then a work time labor operation should be used.

Defect Code: 54 31 13 01 00

and here is the repair instruction:
https://www.zpost.com/forums/attachment.php?attachmentid=935057&d=1383267111
 
Done it ! :D


I collected the straps today. £24 from Soper's Lincoln. I was a bit disappointed at first as they look like something you could buy from the Pound Shop. They work well, however.

20210818_124435.jpg

20210818_124423.jpg

I followed the guides above. You have to be quite a contortionist to get to the rear fixing points via the boot. I used a thick piece of foam to reduce the pain. It's not for the claustrophobic. :cry:

The BMW instructions say to only use the outer fixing point on the front of the strap, but I made a small amendment to that and drilled an extra hole so that it is fixed at both sides. Also a washer to try to spread the load on the already cracked plastic.

roof1.jpg

roof2.jpg

Now the roof pops gently open and closes ultra smoothly :driving:

[vimeo]588897553[/vimeo]
 
Zulu4 said:
Done it ! :D


I collected the straps today. £24 from Soper's Lincoln. I was a bit disappointed at first as they look like something you could buy from the Pound Shop. They work well, however.

20210818_124435.jpg

20210818_124423.jpg

I followed the guides above. You have to be quite a contortionist to get to the rear fixing points via the boot. I used a thick piece of foam to reduce the pain. It's not for the claustrophobic. :cry:

The BMW instructions say to only use the outer fixing point on the front of the strap, but I made a small amendment to that and drilled an extra hole so that it is fixed at both sides. Also a washer to try to spread the load on the already cracked plastic.

roof1.jpg

roof2.jpg

Now the roof pops gently open and closes ultra smoothly :driving:

[vimeo]588897553[/vimeo]
Click to expand...

Excellent news- I may saunter down to soper myself as mine bumps down!!
 
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