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T Roof window adjustment

3 November 2011
Saskatchewan, Canada
My car has had a fair amount of wind noise from the door glass area right from the day I purchased it 9 years ago. With enforced idle time I decided to look at the service manual and the procedure for adjusting the door glass to see if I could reduce the noise. My first observation was that a by-the book adjustment of the door glass requires removal of the body trim pieces around the door opening and removal of both the front and back gaskets so that you can do precise measurements of the glass to the body sheet metal. R&R of the gaskets is not a trivial exercise and I think if I was going to do that I would replace the 20 year old gaskets with new ones - and that is not chump change so I don't think I want to remove the gaskets.

Even if I was prepared to remove the gaskets, I am not sure about the procedures in the service manual. The coupe body section of the service manual has a rather detailed section on the glass measurements and how the glass is supposed to fit with respect to the gaskets. The T section is much more abbreviated. In terms of measurements it pretty much consists of this

T roof.JPG

The manual indicates that if this measurement is incorrect, it refers you back to the glass adjustment procedure for the coupe. What is unclear to me is whether this measurement for the door glass on the T roof is in addition to the measurements set out for the coupe or whether it is the only measurement that is applicable to the T roof and you just skip over the coupe measurements and gasket removal stuff. I am also assuming based upon the drawing that in order to do this T roof measurement the gasket has to be in place. I am also assuming that if this measurement is incorrect it is the bolts for the H adjustment that have to be tweaked, not the B adjustment bolts. The service manual does not provide specifics on how to correct this measurement.

I am also wondering about the applicability of any of the measurement procedures in the coupe section to the T roof. I look at the profile drawings of the glass - gasket interface for the coupe and I am thinking no-way. The following is the profile drawing for the B pillar gasket on the coupe.

B pillar.png

The drawing implies that the B pillar gasket has significant overlap on the back edge of the glass (area in the red circle). This is a photo of the back edge of the glass on my car and I have no gasket overlap on that back edge of the glass.

Back edge of glass closed.JPG

The glass appears to rest pretty much flat against the gasket. I did a smear test with some Shinetsu grease and the only point of solid contact between the glass and the B pillar gasket appears to be that little inner lip on the gasket highlighted by the orange arrow in the profile drawing. You can see the grease 'contact line' in the photo below. Both the driver and passenger doors are almost identical in the way the glass contacts the gasket.

Back edge of glass.JPG

I have seen and been in coupes; but, I have never directed any attention towards the door gaskets. This leaves me wondering whether the gasket profile for the 1 piece gasket on the coupe is completely different than the 3 pieces on the T roof. Unless the B pillar gasket profile is different or my gasket is completely clapped out, I don't think it would be possible to do enough B adjustment to get the glass to sit in the gasket as shown in the second drawing (and be able to get the door closed without whanging it like crazy).

The glass sits the same relative to the gaskets on both doors so its not like one side was adjusted incorrectly. I have done the Hugo kits on the regulators; but, have never touched the glass adjustments. I did check the T specific glass measurement in the first diagram and my passenger door is at the upper end of the spec - 3mm. The driver side door glass is out of spec, something like 5 mm and is just barely clearing that little black guide on the A pillar so a previous owner might have had adjustments done or I screwed up the reinstall of the window regulator which positioned the glass higher. However, there was no material change in wind noise after the window regulator repair so I think the height adjustment issue pre dated the regulator repair.

First question, for those with T roofs does the way my glass sits on the gasket on the B pillar look like your car or do I have seriously out of adjustment glass or a seriously clapped out gasket. Second question, for those who have done a glass adjustment on a T roof, which parts of the service manual procedure did you follow or if you were just trying to fix a wind noise problem did you just tweak the H and B adjustments until the noise was reduced?

Any comments / in-site on addressing the door glass adjustment on a T roof would be appreciated. I did check the Wiki; but, the only procedure I found provided additional advice and procedures specific to the coupe.
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I'll post pics of my 96 when I get home...
It looks like I can see the back edge of your glass like I can on mine so your gasket definitely does not bulge out over the edge of the glass like the service manual drawing suggests. It does looks like your glass is pressing into the gasket more than mine. Have your windows ever been adjusted? What is also interesting is that the back edge of your glass looks to be just about flush with the back edge of that trim piece on the roof panel. The back edge of my glass looks to be about 4-5 mm back from that trim piece, much closer to the panel covering the B pillar. If yours is correct my glass appears to be mounted in the door about 5 mm back from where it should be.

Now I have two problems to think about!
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I have had a fair amount of wind noise from the drivers side window of my car since getting it nine years ago. It only starts above 100 mph or so. I've not dealt with it, as the top is rarely on, and there is always lots of wind noise! Around here 100 mph gets you a $2500.00 fine, a tow job, no car for a week, and six points on your licence! I would like to make make it go away however. I expect Kaz or Joe, now that he is retired and awaiting his new NSX, have addressed this issue a time or two! Hopefully they will have some thoughts on a fix.
the last person to do an adjustment was Larry B over 6 years ago...
I have had a fair amount of wind noise from the drivers side window of my car since getting it nine years ago. It only starts above 100 mph or so. I've not dealt with it, as the top is rarely on, and there is always lots of wind noise!

My wind noise becomes objectionable well before 100 mi/hr. It is significant enough at legal speeds that I will pick another vehicle if there is more than a couple of hours of driving. However, out here in flat-land where its common to have wind gusts in the 70+ km/hr range the air speed can easily approach 180 km/hr. The direction of the wind relative to the cars motion does very much affect the noise level and where exactly the worst noise source is located.
My wind noise becomes objectionable well before 100 mi/hr. It is significant enough at legal speeds that I will pick another vehicle if there is more than a couple of hours of driving. However, out here in flat-land where its common to have wind gusts in the 70+ km/hr range the air speed can easily approach 180 km/hr. The direction of the wind relative to the cars motion does very much affect the noise level and where exactly the worst noise source is located.

Subscribed, as I’d love to reduce the amount of wind noise from the driver’s door on my ‘99 T...
I think the forwards & backward adjustment of the window (away or towards the B-pillar) can be done by loosening the two bolts holding the window to the regulator and shifting them before retightening, the holes on the regulator are oval-shaped (or by shifting the entire regulator assy itself per the FSM). Can be done easily with the window ~3/4 of the way down to expose the two bolt through holes in the inner door skin. After doing that you should check how much the glass protrudes against the front sash rubber and rubber on the door handle so that it doesn't rip them. There was a TSB for that issue here https://www.nsxprime.com/FAQ/Reference/tsb/91-002.htm.

FWIW, my coupe did not have any overlap of the gasket along the B-pillar either before I replaced it or after with the updated spec of gasket & front sash. However, the new spec of coupe upper gasket does protrude past the window along the A-pillar trim most of the way up, just not the vertical part at the B-pillar. I had horrible wind noise and water leakage from the front sash area before, currently have no wind noise at all but the windows will not go from 95 to 100% up without the doors open since I think they press too hard against the gaskets and the regulator motors aren't strong enough.

I'm sure the targa is much harder to get perfect but just to give an idea of what can happen if the windows are adjusted to angle too far inwards (to the center of the car). Gives a good seal against wind & water but there's a fine line between a good seal and too much resistance for the motors to handle. I'll be adjusting mine again soon, I think that kind of angle adjustment is done at the front & back window guide rails which both have 2 bottom adjusters and 1 top one that's non-adjustable, but the two sashes have an adjuster on the bottom. I likely won't bother with the factory methodology with seal removal and stuff, just mark the original adjustment, then adjust-test-adjust-test by feel to hit the best efficiency point. If there were any experts left in my area with experience doing that I wouldn't mind paying them for once.
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You have an interesting point about the for-aft adjustment of the glass where it connects to the regulator. I had assumed that if the tracks were fixed, there was little opportunity for for-aft movement of the glass by fiddling with the regulator attachment or adjusting the regulator. Of course, when I did my Hugo kit install I went over board in taping the glass in place on the door to avoid an accident so if there was some for-aft movement within the tracks it would not have been obvious. The point about the for -aft adjustment is doubly interesting because the boots on the rear sashes on both doors are split just like in the TSB. They have been split since day 1 when I got the car so I assumed it was an NSX door thing like slow windows and was caused by the lateral movement of the glass as you closed the door. I have a set of new rear sashes; but, never got around to installing them. The failure of the boots on the sashes would jive with the fact that my door glass seems to sit too far aft - certainly farther back than docjohn's. Although TSB-002 is particular to coupes, it is interesting that the solution in the TSB is not to reposition the glass; but, to reposition the sashes.

The tears in the sashes are only on the back sashes. I will have to go out to examine and play with the window to see if it causes the 1 mm movement in the rubber boot on the front sash. If it is not even touching the boot, then adjusting the glass forward (if that is possible) might be the solution. This should push the edge of the glass further into the weather strip along the lower A pillar area (at and above the sash) which is where I am getting wind noise.
The four glass sliders do not slot perfectly into the window tracks, so there is some wiggle room (literally) fore-aft and in-out especially when the window is not fully up and pushing against the stoppers in the door. The 1991 FSM says there are two possible fore-aft adjustments (really 3) which are the regulator mounting bolts to the door, mountings bolts from window to regulator, and the mounting bolts for the tracks/guides. If you go too far adjusting any of those then the glass sliders might bind in the tracks and won't let the window go further even with a fresh rebuild & regrease (like my passenger side does at 95% closed, which only showed up a month or so later). Both my rear sashes are also torn at the backs.

I'd keep the door panels off for a while after "finishing" any adjustments to do some on-road testing for sure. Make sure the windows go up & down without binding, check wind noise at all speeds, spray with a hose, etc. There are so many variables car-to-car that I don't think the manual can account for, for example having fresh conformable gaskets vs. old ones which are already formed & set in place. That's why I'd prefer keeping as much together as possible, perform & record an adjustment, then drive around and come back to make any changes. There's all 3 dimensions at play so trial and error seems inevitable. I'm sure temperature and humidity play a role too.

Apologies since I keep referring to coupes, but replacing my front sash & door gasket fixed my wind & water intrusion issues from the same place you're referring to and I tried to maintain the same alignment after my regulator rebuild. I have no idea if this applies to later year targas or not (EDIT: 95+ should already have updated spec), but this Kaz post explains the design change of the front sash & gaskets http://www.nsxcb.co.uk/entry.php?870-Final-Touch. The old spec ones are much harder and less conformable, so I could poke my finger into the sash on the highway and let in a torrent of air. Yours might already be the later spec but worth a check. Like you said, you might try some combo of adjusting the windows forward and inwards slightly to form a better seal against the front sashes & door gasket.
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I will have to dig out my service manual (a 1997+ version) and have a look at the regulator / glass adjustment provisions. I was mainly focused on the remove & replace component for the regulator rebuild so that provision is drawing a complete blank for me. My car is a 2000, so presumably it has the later spec gasket assuming that was an issue with early targas.

If I am doing the deep dive back into the doors, this is now next year country. Somebody had really torn up my old door liners and I attempted to replace them with some heavy poly vapor barrier. Looked better than the chopped up old door liners; but, didn't fit perfectly. If I am going back into the doors I am going to order some new liners from Amayama for replacements. Unfortunately, by the time they arrive the car will probably be back in storage.

First of all, for all NSX-T owners, please pay extra attention to the lip of the rear pillar weatherstrip every time when placing the roof panel back in place.

This is especially important at the opposite side from where you install the roof.
Regardless of the RHD/LHD, the owners tend to place the roof while standing at the driver side so please pay extra attention to the lip at the passenger side.


If the lip was not positioned properly and if extra friction exists at the glass surface or weatherstrip, then next time when you operate the power window,
you are going to tear off part of the weatherstrip.


Some owners managed to repair it but most of the time, the repair becomes weak and it will eventually repeat again.


You don't want to know the price of the replacement….

Regarding the glass alignment….

Unless you are replacing all the parts around the window or doing DIY and happy to repeat the same process again in the future,
personally, I won't spend too much time on it.

I won't even touch it on many cases if parts are not replaced.

This is because the procedure and the spec in the workshop manual are based on new parts and the car just leaving the factory assembly line.
And the clearance spec is just a reference only and you need to customise it for each NSX differently.
Some has different number of extra spacers/shims and others don't.

I have full respect to the person who adjusted the glass alignment on each NSX at the factory.


For your reference, if doing the proper full alignment process, done with it once and for all,
you will need all these new parts (rear sash missing in the photo) replaced and this is just for one side.

And this photo is for the coupe.
With NSX-T, you need different type of multiple weatherstrips and again, you don't want to know the price.....


Adjusting the alignment on the tired weatherstrip that already took set, aged and hardened door sash, deformed and worn guide rails,
loose glass guides (above photo, some has tiny shims as well), etc can't be done using the factory spec.

If the weatherstrip was not installed properly at some point in the past and already took set under the same condition for years,
then for almost all the cases, best not to re-install it properly and keep it installed in the wrong way.

You can try it but most of the time, it actually made the wind noise and water leakage worse.

With NSX-T, when all of the parts are fresh/new and if the window was aligned properly or fresh out of the factory,
you can't fully raise/close the window on Day 1 with the door shut.


I'll touch on this later but with NSX-T, the narrow section of the weatherstrip (below yellow line, narrow band between two blue lines)
next to the B-pillar garnish is significantly harder/stiffer/higher shore that the friction against the power window glass is much higher than the Coupe spec when new.

I think Honda released TSB about this when NSX-T was first released on the market.

The wind noise can happen not just because of the air passing the gap between the glass and the weatherstrip.
With NSX-T, the air flow along the A-pillar -> side edge of the roof -> window glass -> B-pillar metal garnish are different from the Coupe and
on some NSX, I noticed that the wind noise was caused by the different angle of the rear sash causing
different air flow hitting the edge of the B-pillar garnish and together with the weatherstrip not installed properly,
the noise was happening outside but sounded as if entering the cabin.

If it's safe to do so while driving, you can carry out initial check on the source of noise by running the finger along the weatherstrip.

As a side note, Honda changed the design of the front sash and the weatherstrip on Coupe in early '90s.
NSX-T was introduced in 95 so by that time, the front sash was already in the new spec that followings won't apply.

Originally, the window glass and the front sash (A-pillar section) were being pressed fairly hard against the upper weatherstrip.

Then, the design on both parts changed (but without changing the parts no of the front sash) and now the weatherstrip along the A-pillar and
the roof (coupe only) would wrap around the edge of the glass instead of being pressed hard against the weatherstrip.



For the weatherstrip next to the B-pillar garnish (the area that in question by Old Guy), on Coupe, the area is fairly soft so while it's not fully wrapped like in the workshop diagram but
more of the glass edge being sunk into the rubber.

With the NSX-T, the section is really stiff/hard.

The retainer behind that section and the B-pillar garnish design are different between the Coupe and the NSX-T.

Never compared side by side but I think the design/shape/thickness of the weatherstrip at that specific section creates this stiff/hard effect on the NSX-T.

So, the edge of the window and the glass touching the narrow section marked in two blue lines in earlier photo would be pressed hard against the rear pillar weatherstrip and not wrapped at all.

You can see in the photo that when a certain tool pressed against the same section of the B-pillar weatherstrip, the tool would sunk fairly easily on the Coupe whereas on NSX-T,
the whole area would push back the tool with very little change in the weatherstrip shape.

Thus, making good contact against the glass and the rubber will never wrap around the edge (despite the workshop diagram) with NSX-T.

Now the alignment.
[Edit: Before making any adjustment, please double check the alignment of the door panel and the roof section itself.
Making glass adjustment against wrongly positioned door/roof panel would result in waste of time....]

Old Guy, your glass alignment is too far towards the rear.
That's why the rubber lip of the rear sash was torn/cut.

Also, at B-pillar section, you glass is not touching hard against the area where I placed the tool as well as marked in two blue lines.

Don't know it's caused by just the glass alignment or possibly the weatherstrip not installed properly.

You don't want start lifting that weatherstrip because there are lots of sealant and butyl tape involved.


If adjusting the alignment by re-using all the parts and without knowing the state of the screws of the glass guide, worn/deformed guide rail, etc,
the key factor is the glass stopper/end-stop/ stopper plate.

Two at each door located near the top.

Because of its shape/design, when the glass hits the stopper, it will change the angle of the glass.

The glass itself is not flat and 3D shape.

Therefore, you need to have 3D image in your head and imagine how the entire glass moves when it hits the stopper.

At the front sash, there is additional 10mm bolt at the forward section of the sash body and while it's not used for the alignment purpose,
the torque of this bolt can change the glass alignment so be careful.

With NSX-T, if re-using the parts, you may want first marking the glass with a line 2mm away from the edge around the A-pillar and roof section.
No need along the vertical B-pillar section.

Use this as a reference for the height and forward/aft glass position adjustment.

I normally need full one day for adjusting just one side of the door even when using the new parts so good luck if re-using old parts.

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always impressed how Kaz demystifies the tech.....bottom line...collagen filler and Botox....spare the knife:biggrin:
Thank-you everyone for the input on the window adjustment. It has likely steered me away from really messing things up trying to mix the coupe adjustment with the T roof adjustment. It is nice to know that the gasket wraparound on the glass shown for the coupe is not applicable to the T roof.

About the 'don't want to know' comment on the price of the T roof weather stripping, I already know. About 8 years ago I checked on the gasket prices when I initially thought I might do something about the wind noise. That rude surprise immediately altered my thoughts; but, I did purchase some shin etsu silicone grease to religiously massage into the weather stripping every year with the objective of trying to preserve my weather strip. My review of the extended section is the service manual covering the replacement of the front and rear weather strips on the T roof also discouraged me from experimenting with removing the gasket. I am definitely liking the Botox and collagen treatment rather than major gasket surgery.

After reviewing the TSB on the sash tearing, the tearing on my rear sash boots and the pictures of docjohn's windows, I had also come to the conclusion that my windows were probably too far back. Kaz's comments confirm that. The back edge of the rear sash was already flush with the back of the door so there was no opportunity to move the rear sash further back to eliminate stretching of the boot. It will be next spring before I get around to checking to see how much provision there is for moving the front sash forward. I was out checking the contact of the glass with the front sash boots and there is about 1 mm of stretch in the boots when the glass reaches full up. The front boots don't have any tears and to keep it that way they will definitely have to go forward in order to move the glass forward.

While moving my windows up and down to check contact with the boots on the front sash, I noticed that as my driver side door approaches full up in that last 4 - 5 mm of movement it rocks slightly front to back. This rocking movement is around 2 mm. I assume that this rocking movement is caused by the rear glass stopper hitting its stopper plate before the front glass stopper hits the front glass stopper plate. The passenger side window does not display this rocking in the glass as it reaches the full up position so I am assuming this rocking motion is incorrect and is a sign of incorrect setting of the stopper plates on the driver side door?

When I look at the service manual on pages 20-14 to 20-16, even though the manual refers to this for the H adjustment on the glass, all the adjustments (if I just loosen the locknuts and don't mess with the adjustment screws) appear to allow for for - aft movement in the glass. Once I get the glass and the front sash positioned forward 'more correctly', I am assuming that if the glass needs to be repositioned in the 'H' adjustment this would be accomplished by adjusting the glass stop plates? When measuring the height of the glass on the driver side as described in the service manual it is already sitting too high. Kaz's 2mm line on the glass is more like 5-6 mm on my driver side door and if I move the glass forward it will definitely be hitting the black guide on the A pillar. If adjusting the stop plates is not the correct method for reducing the height of the glass as described in the adjustment for the T roof, what is? I am completely missing how moving the glass for and aft would alter the height, other than the change caused by the slight curve in the top of the glass?

As a final ask, can other T roof owners please provide me with a measurement of the clearance between the door glass and the B pillar trim in the approximate area shown by the arrows in the photo below.

gap measurement.jpg

My clearance is approximately 5.2 mm on the passenger side and 6.7 mm on the driver side. If there is a 'typical' clearance, using that as a starting value for adjusting the glass may save a lot of time in doing the adjustment.
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Just went out and measured mine. 4.5mm driver side. 5mm passenger side.

Yours is worse than mine! The rubber boots on your rear sash must be torn? What year is your car? Mine is a 2000. Since docjohn's car is a 1996 and he has a lot more clearance I wonder if there was an assembly change for later T roofs cars during the production run .
My clearance is approximately 5.2 mm on the passenger side and 6.7 mm on the driver side. If there is a 'typical' clearance, using that as a starting value for adjusting the glass may save a lot of time in doing the adjustment.

5.8 mm driver, 5.2 mm passenger.
.so give or take a few micrometers I'm at 7mm both windows half way up in the middle...
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A quote from Old Guy ...some shin etsu silicone grease to religiously massage into the weather stripping every year with the objective of trying to preserve my weather strip

This will save your rubber, and keep them plyable especially for Targa owner.

Yours is worse than mine! The rubber boots on your rear sash must be torn? What year is your car? Mine is a 2000. Since docjohn's car is a 1996 and he has a lot more clearance I wonder if there was an assembly change for later T roofs cars during the production run .

The boots on my rear sashes are torn a little (95). The rear weatherstrip is torn a bit too, mostly attributable to age. I bought new front & rear weatherstrips from MITA a few months back to have on hand when I'm ready to replace them.
I am going to have to do the entire glass and gasket replacement alignment on my car after paint. After reading this, looks like I'll have to set aside a few days... [MENTION=25737]Kaz-kzukNA1[/MENTION] if you can, could you post your notes on the full install and alignment procedure here? As our NSX gets older, I think there are many owners who will need to replace the rails, sashes and door gaskets in the next few years. I will be doing this miserable job in a month or so and would appreciate any advice!