Targa top seals and fitment - unexpected issues

[Otter74]

Replacing the header seal with Dan's part was next on my to-do list for my Targa, but at my girlfriend's encouagement I had a shop address a few other things on the car, and decided that while they were there I might as well have them install the new seal and tweak the door/window fit for further improving sealing and wind noise.

I don't have photos - I'll post some when I take a few - but I've seen a video, and now the entire top, rather than just the outer few inches on each side, is sitting proud of the windshield header. maybe a few mm. This means, of course, that it will be even noiser. There is still a gap at the vent windows (large enough to stick a finger in on the right door), which are at the top of their vertical travel limit, which is not unexpected because the top is sitting too high. I figure there's no point in tweaking door glass and quarter window frames any more until the top is sitting where it needs to be.

The top was rebuilt by Dan Pechtel about ten years ago, and the header seal is new from Dan. The new seal seems to be a little shorter on the vertical edges than the old one, and there's A-pillar seals now a bit of a gap between the A-pillar seals and the lower door opening seals.

this suggests to me maybe that either the latches need adjusting, the top may need another partial rebuild, or both. But surely I ought to have a top sitting in the correct vertical position wrt the body with the correct seal, no?

it's possible the top isn't all the way back against the targa bar - I'll check that when I take a look at the car. But I can't see why the fore-aft position wold be any different than before.

[rwest]

I would expect that either the new seal isn’t seated properly; maybe they didn’t clean out the old glue or they used a factory seal rather than the one you brought them.

[Tony V]

Mine didn't fit either. Installed just as Dan's instructions stated. Changing that seal was the worse decision I've made on my Targa.
Good Luck,

[Otter74]

It looks rather like the front of the top is a little bit too far forward, particularly when I look at the fit by the left vent window, and that if it were able to move back about 5mm, it could sit down. The vent windows - certainly the right, which has a gap large enough to stick a finger through - is as high up in the door as it can go. The top was rebuilt by Dan about ten years ago, and the seal is Dan's, too.

[bobeisenberg]

Just wrestled with a new Dan front seal in my ‘87 Targa. First, for some years, I ncluding on the ‘87, the new seal doesn’t extend far enough down the A-pillars to meet the body seal at the front of the door opening. Dan warned me about this. You need to graft a piece from the bottom of the old seal onto the bottom of the new. Cut old and new at a 45 degree angle and bond with super glue. The profiles don’t match up exactly but it’ll work. Second, I’d be surprised if Dan’s seal would sit that high if properly installed. I agree with RWEST’s comment. Next, don’t waste time with any window adjustments until you solve that front edge problem. Happy to share what worked for me but would be easier to talk by phone. PM me if you’d like to chat. Good luck!

[dhamilto]

Just a thought - maybe careful scrutiny of the "Sealing of 911" manual might reveal something useful. A Google search locates a thread on this forum... I cannot remember how much movement there is on the latch positions, but the first thing I would do is slacken the Targa latch attachment bolts, find a way to hold the front edge of the Targa roof down evenly, and tighten up the bolts. There should not be any gap between the roof and windshield frame. I think it is supposed to "sit" just over the edge with no gap underneath. Best of luck!

[Tony V]

As I have a ‘74, I took out the latches to add a couple of washers to cinch the top down tighter. While it helped bring down the center section, the corners by the vent windows, still sit proud.
Dans help consisted of telling me it couldn't be the seal and that my newly refinished Targa top must have been built incorrectly (since he’s the only guy that knows how to rebuild them). My top fit great before replacing the front seal but leaked water around the vent windows and I wanted new and shiny. Lesson learned. Don’t mean to poke at a sacred cow but that’s my experience and a few other guys that have the same experiences but chose to remain silent so as to not anger the fans of his work and products.

[Hotshot]

Have you guys seen the seeking and seal install video that Porsche made? It’s in here.

[Otter74]

Originally Posted by bobeisenberg

Just wrestled with a new Dan front seal in my ‘87 Targa. First, for some years, I ncluding on the ‘87, the new seal doesn’t extend far enough down the A-pillars to meet the body seal at the front of the door opening. Dan warned me about this. You need to graft a piece from the bottom of the old seal onto the bottom of the new. Cut old and new at a 45 degree angle and bond with super glue. The profiles don’t match up exactly but it’ll work. Second, I’d be surprised if Dan’s seal would sit that high if properly installed. I agree with RWEST’s comment. Next, don’t waste time with any window adjustments until you solve that front edge problem. Happy to share what worked for me but would be easier to talk by phone. PM me if you’d like to chat. Good luck!

I don't think I had seen that in any of the seal-install threads I had read - thanks for mentioning that. Would have been useful to know before they did it, but I can make do by using a piece of the old seal and splicing it into the A-pillar seal.

Originally Posted by dhamilto

Just a thought - maybe careful scrutiny of the "Sealing of 911" manual might reveal something useful. A Google search locates a thread on this forum... I cannot remember how much movement there is on the latch positions, but the first thing I would do is slacken the Targa latch attachment bolts, find a way to hold the front edge of the Targa roof down evenly, and tighten up the bolts. There should not be any gap between the roof and windshield frame. I think it is supposed to "sit" just over the edge with no gap underneath. Best of luck!

Yes, I've got a copy of that document saved and I actually left a printed copy with the shop and referred them to it. Still, in the interests of keeping shop bills from getting out of control, I'd rather spend my own time on adjusting the top itself. I know it's *possible* to get the top fitting flush with Dan's seal, because I've seen the results on other cars. There was another Targa in the shop with a perfectly-fitting top. I'm going to ask them if they can try putting that top on my car and seeing how it fits. If it fits the way it should, the problem lies in my top. If it persists, it's in the car or the interaction.

Originally Posted by Hotshot

Have you guys seen the seeking and seal install video that Porsche made? It’s in here.

You mean the German-language video on top/sealing adjustment and fitting?

[Hotshot]

Yup, that one. People have translated it. They talk a lot about the front. My fronts in thankfully in good shape and fits bang on when I got my roof back from Dan.

I found that video useful with my side seals..

[Otter74]

I asked the shop to see if they could swap the top from another Targa that was in to do an A-vs-B. If the other top fits perfectly (as it does on the car it's on), the problem lies in my top. If the fit is still off, the problem lies either in my car or in the interaction between the two. Unfortunately, that car's top used the later latch system. If anyone in Chicagoland has a compatible top that is known to fit very well on their car that I could try out on mine, I'd love to try it.

[Otter74]

Update: got the car back and drove it for a bit on the freeway on the way home. Noise is clearly different from before - it used to be highly localized at the corners but only a little bit quieter. Window and vent frame fit is clearly better. When I push down on the front of the top, a few inches back from the edge, I can feel some play in the frame in the center where the top sits most proud. So next step is to look at what the top may need and whether it's anything I can tighten or adjust out. Had a big, stupid grin driving home, just like the day I got it in 2015, because I missed driving it.

[Jack Stands]

I noticed that your door windows are riding past the top of the vent window frame (tearing the rubber corner piece). That might be putting upward pressure on the sides of the top.

[Jack Stands]

This should be the upper window limit. The vent window frame can be adjusted up and down, and the adjustment slots can be elongated if needed. Top & window adjustments do take patience till correct.

[Discseven]

Originally Posted by Otter74

1) entire top, rather than just the outer few inches on each side, is sitting proud of the windshield header. maybe a few mm.
2) I figure there's no point in tweaking door glass and quarter window frames any more until the top is sitting where it needs to be.
3) header seal is new from Dan. The new seal seems to be a little shorter on the vertical edges than the old one, and there's A-pillar seals now a bit of a gap between the A-pillar seals and the lower door opening seals.
4) the top may need another partial rebuild, or both.
5) But surely I ought to have a top sitting in the correct vertical position wrt the body with the correct seal, no?
6) it's possible the top isn't all the way back against the targa bar - I'll check that when I take a look at the car. But I can't see why the fore-aft position wold be any different than before.

Hey Otter. Here's my thinking for you:

1 - Could be three things. a) New seal is not seated fully down into channel. b) If new seal is fully seated in channel, seal's too thick. c) Hooks that hold roof to crossbeam have unhooked... allowing roof sections to be pushed up by header seal. Can put finger up by hook(s) to feel if they have unhooked. If hooks are unhooked from crossbeam, the seal's position/install and/or dimensions deserve questioning.
2 - Agreed. Position of roof front & back and height at front and back should be set before investing in door/window adjustments.
3 - A-pillar can be pulled---to a degree---to make a nice joint between it and lower door seal. This requires adhesive to prevent the a-pillar section from pulling out of desired position.
4 - Disagree. Sort through what you have in hand---answer's there.
5 - Agreed. With correct seal/install and perhaps some fine tunning.
6 - If fore/aft position was good... agree that it should still be good.

Is hard to armchair for sure what's going on with your roof given Targa tops requiring the number of right things happening with them to fit right. From what's been said, am most inclined to believe the front header seal is either not what it should be in and of itself or was not installed per Dan's specs---he's very specific about how to get his seal in position.

I believe ground zero is the seal's install. That said, I'd sort this out by doing the install over again EXACTLY as Dan wants it done. If the seal is right and the install is as Dan wants it, you'll be happy with the fit. If the install is spot on and there's still an issue, I'd be confident the seal is not what it should be---time to get on Dan's case about the seal.
.

[Otter74]

@Discseven, thanks for the thoughtful note. Fore-aft position of the roof is, indeed, what it was and is fine. Gap to the Targa bar is as expected. The shop did do some window and vent frame alignment and that definitely helped, both for noise and sealing, but I told them there was no point doing more until I solved the top location. The guy who worked on the car said he'd have to enlarge the adjustment holes in the door for the vent window to raise it any further, and that seemed extreme to me (and also pointless if top is known too high), but sounds like that is considered OK. Still, only OK once top is down far enough. If nothing else, I don't have gaps above the vent windows that I can stick a finger through any more. I do think that either the front top hooks or the clips inside the top need some investigation - if I push down on the middle part of the top, where it sits highest, I can get it down where it needs to be with hand pressure. This is my reason for thinking I have top issues. I hope it's something I can adjust out. I am so far giving the shop and tech the benefit of the doubt about installing the seal correctly - they were otherwise very detail-oriented and methodical, and the instructions were included with the seal. This (from one of Dan's messages) is a possibility: "7. Vinyl and reinforcement worn out so front beading sits up and catches air."

Can a new seal be removed and reinstalled? I'd assumed not.

At any rate, I'm giving my Saab ('85 SPG) some maintenance attention today, and will start looking at the top issues once I swap the 911 back into my home garage tonight.

[Otter74]

@Discseven thanks for suggesting the hooks on the underside of the front of the top. I looked today, and indeed one was unhooked. Re-secured it and that takes care of 2/3 of the problem area. Getting there!

[LIRS6]

FWIW, I had a glass out re-paint done, shop put in a 964 front seal ... well we all know that they don't fit correctly. Got a front seal from Dan, ensured that it was seated properly and have had ZERO issues with it. No gaps etc to deal with, top sits snugly.

I would check to see if Dan's is seated properly on yours.

For anyone doing any work necessitating removal of your original seal, suggest strongly to carefully remove and hold onto it.

OP - is that Casablanca Beige Metallic?

Jason

[Robey5]

I installed Dan's front seal, and followed the instructions precisely as I could, including the area that indicates that beer consumption (at step 8a, I believe) along with patience is/are required for a correct fit.

My old seal was junk (came out in 3 pieces), and I went through a LOT of side glass adjustments to get us *better*; after all it is an old car by modern standards - the wind noise is much better, though will never be perfect. One thing to bare in mind is that: once one of those hooks is allowing your top to "un latch" you may as well put a sail in front of your car: it will create a TON of wind noise. That hook-latch is one area is one that I am currently in a battle on.

Finally: cleaning that seal channel out is a MUST. I do not think that you will be able to get that seal out once it's installed without destroying it (because of the seal adhesive).

[Otter74]

@LIRS6 Yes, it is. It's a very striking color that I like a lot!

I'm ordering some replacement Targa top clips and window stops for the vent frames and will jury-rig something to fill the seal gap lower in the door - if it improves noise I'll order a new lower door seal eventually. I still need to figure out why the top covering in one section is slightly loose.