Advice on hardtop Adjustment

gwatson

Senior member
Aberdeenshire
Does anyone have advice or a doucment which shows how to adjust the fitting of a Z4 hardtop.

I am collecting a used one at the weekend. Whilst I understand all UK Z4's all prep'd for a hardtop, I may still experience some wind noise at higher speeds. Is there anything I can do, or is it a stealer visit = £££'s.

G
 
I'm not sure there is any adjustment. Just two connectors where the top fits behind the driver and passenger's shoulder and a central lock above the rear view mirror to lock the front down. I've got the manual that came with it so I could scan it and email it to you ... let me know.
Kevin :)
 
Hello-

I was lucky to find my used hardtop with a friend here in Florida (KCSails) and he even delivered it to me in Gainesville. :driving: Thanks KC!

05Z43.0540001.jpg


Once attached, I had some top right windshield/top wind noise. I searched and found this post in Z4UM (now a lost data base). Thank GOD I printed it out so I would have it in the garage when I went through the steps.

I don't know who posted it so thank you, whoever you are, for your very complete instructions! :thumbsup:

BMW199.700.jpg


BMW200700.jpg


BMW201700.jpg


BMW202700.jpg


BMW203700.jpg


Good luck. :D Post a follow up with pictures!

Best!
Jack
 
Ah okay, that's good the hear. It's just a remember a few people complaining of wind noise which their dealer fixed.

Thanks for the offer Kevin, but the owner is supplying the manual with the roof.

Out of interest, what's your experience with the hard top. Apart from it making the car look more aggressive and the added advantages in the winter. Does it make the car quieter on the motorway etc? Z4 suffers from a lot of road noise with the big tyres.

P.S.... wouldn't it be cool if one of the custom sunroof companies would make a kit for the Z4 hardtop just to let more light into the cabin. Z4 is quite dull inside with the roof up, although the hardtop rear window is bigger.
 
JackB1 said:
Hello-

I was lucky to find my used hardtop with a friend here in Florida (KCSails) and he even delivered it to me in Gainesville. :driving: Thanks KC!

05Z43.0540001.jpg


Once attached, I had some top right windshield/top wind noise. I searched and found this post in Z4UM (now a lost data base). Thank GOD I printed it out so I would have it in the garage when I went through the steps.

I don't know who posted it so thank you, whoever you are, for your very complete instructions! :thumbsup:

Good luck. :D Post a follow up with pictures!

Best!
Jack


Brilliant. Exactly what I need. Hopefully it will be ok though. Will def get some pictures posted :) Cheer.

G
 
gwatson said:
Ah okay, that's good the hear. It's just a remember a few people complaining of wind noise which their dealer fixed.

Thanks for the offer Kevin, but the owner is supplying the manual with the roof.

Out of interest, what's your experience with the hard top. Apart from it making the car look more aggressive and the added advantages in the winter. Does it make the car quieter on the motorway etc? Z4 suffers from a lot of road noise with the big tyres.

P.S.... wouldn't it be cool if one of the custom sunroof companies would make a kit for the Z4 hardtop just to let more light into the cabin. Z4 is quite dull inside with the roof up, although the hardtop rear window is bigger.

Hi

I've not had much experience with the hardtop ... drove it home 80 miles from the dealer, took it off and hung it in the garage ... never been on since! (only had the car since August). Certainly didn't notice any unexpected wind noise on the motorway ... perhaps it was fitted properly in the first place. But, at least I'll know how to check it when I put it on for the winter. A 'sunroof' would be pretty cool ... compared to having the roof down everything seems quite dull inside!Cheers. :driving:
 
Hi Jack,

Thanks for posting up the adjustment instructions last week for the hardtop. Well picked it up yesterday and like you there is a bit of wind noise from the top right. At the back right (if you're sitting in the car) it's much closer to the bodywork than the other side. So is the problem it's too low at the back right, thus pulling the front right up? Is it only this side I should adjust?

Overall I am very happy. It looks awesome, very agressive. It's a bit quiter, even more when I fix it hopefully. :) :)

Thanks in advance for your advice.

Graeme
 
Jack,

Reading through the instructions again, which way should I adjust the nut to lift the back up? I assume anti clockwise to wind it out and make it sit higher at the back.

Also, where do you get rear window heated window cable from? I can't find it. There is a wire which connects to the metal the rear hardtop bit slides into, is it that I remove and connect to the hardtop, or is that to detect if the roof is on, therefore disable the roof function.????

G
 
I've got an extra set of hardtop adjustment instructions that came with my car, I thought that they might help. Interestingly it looks as if you can adjust the hardtop from side to side too. I've scanned them as a PDF but it doesn't look as if I can upload a PDF, is that right?

Could someone tell me what size spanner is used for adjusting the hardtop on the vertical adjustment nuts (picture 10 above)? I haven't got a spanner that fits but from the look of it it's a 21mm nut, is that right?
 
I confess writing those instructions back in the Z4um days, must have been one of my first posts. Guess I have the text and images somewhere in my files still, but smaller cropped versions of the images, stored in Photobucket (an image storage site at that time) are probably lost by now. In addition to the booklet that came with the hardtop there are some useful TIS documents, e.g. adjusting the front with shims, that I was unaware of when writing the instructions.
 
I purchased a hardtop recently and have been experiencing the same issue reported by JackB1 near the start of this thread. I somewhat regretted my purchase until I followed the advice laid out above; thank you all for writing up these guides and putting in the effort so that they are accessible to this day. I took some photos along the way, hope they could be of use to someone.

So the way my hardtop used to look at the front is as below, where the middle section interfaces well with the top of the windscreen, but a gap seems to open up toward the outer edge. Also worth noting, I only had this issue on the driver's side so I only needed to address that side.

PXL_20241116_113707347.jpg

Toward the back of the hardtop, behind the driver's window I could see that the gap is more than the 5mm as recommended by the guide further up this thread.

PXL_20241116_113748581.jpg

Therefore I followed the guide above to bring this gap down to a level akin to the passenger side.

1. I undid the hardtop front anchorage point with the allen key;

PXL_20241116_114044907.jpg

2. I removed the trim panels next to the headrest to access and undo the rear hardtop anchorage points;

PXL_20241116_114414491.jpg

3. Next I removed this plastic ring. In the image above you'll see that I skipped ahead and did that already, apologies for the continuity error;

PXL_20241116_114145025.jpg

PXL_20241116_114213156.jpg

4. I disconnected this electrical connector for the window heater;

PXL_20241116_114647196.jpg

PXL_20241116_114702039.jpg

5. Now began the actual height adjustment. I loosened the locking nut (the upper one) so that it spins freely;

PXL_20241116_120609684.jpg

6. I turned the lower nut to adjust the installed hardtop height. My hardtop gap was >5mm, so to lower it I loosened this nut 1.5 turns (wound it upwards);

PXL_20241116_115728269.jpg

7. I re-tightened the locking nut to finish.

The adjustment was now done, so I re-installed the hardtop by tightening the front and rear anchorage points to check how it sat. I'll put further images below, as the webpage is no longer letting me add photos.
 
After the adjustments, my hardtop is now sitting like this at the front;

PXL_20241116_123226294.jpg

This is now the measurement at the rear;

PXL_20241116_120440226.jpg

It now sits symmetrically, and makes a hell of a lot less noise at motorway cruising speed which is fantastic.

Things to remember;

Remember to put the plastic rings back, and also remember to reconnect the electrical connector for the window heater. This was probably the worst step in the process, I couldn't get this thing back in for love nor money. I eventually popped it in by first pulling it toward me to get as much cable slack as possible. I had to remember to exercise patience; these hardtops aren't exactly a dime a dozen. Particularly in this colour...
 
hq114 said:
After the adjustments, my hardtop is now sitting like this at the front;

PXL_20241116_123226294.jpg

This is now the measurement at the rear;

PXL_20241116_120440226.jpg

It now sits symmetrically, and makes a hell of a lot less noise at motorway cruising speed which is fantastic.

Things to remember;

Remember to put the plastic rings back, and also remember to reconnect the electrical connector for the window heater. This was probably the worst step in the process, I couldn't get this thing back in for love nor money. I eventually popped it in by first pulling it toward me to get as much cable slack as possible. I had to remember to exercise patience; these hardtops aren't exactly a dime a dozen. Particularly in this colour...

Fantastic guide, thank you. I know what I'm going to be doing on my days off, as my hardtop has the same issue as yours did initially! :thumbsup:
 
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