91 Targa Partially Stripped?
06-19-2017, 12:36 AM
#1
Racer
Thread Starter
91 Targa Partially Stripped?
91 Coupe
All screws seem to loosen and tighten normally except for the passenger front screw which when tightening it, it needs to be tightened an excessive number of turns compared to the other three screws, it does tighten up pretty snug (but not as snug as the other three). I am able to remove and replace the Targa Top but it concerns me that either the screw or the hole on the front passenger side is partially stripped. Not sure how to proceed.
All screws seem to loosen and tighten normally except for the passenger front screw which when tightening it, it needs to be tightened an excessive number of turns compared to the other three screws, it does tighten up pretty snug (but not as snug as the other three). I am able to remove and replace the Targa Top but it concerns me that either the screw or the hole on the front passenger side is partially stripped. Not sure how to proceed.
06-19-2017, 05:46 AM
#2
Le Mans Master
Swap them around to see if the problem follows the screw or not. Both screws and mounting brackets are available online and easy to swap out.
Last edited by bac22; 06-19-2017 at 05:49 AM.
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koritz123 (06-19-2017)
06-19-2017, 09:15 AM
#3
Drifting
91 Coupe
All screws seem to loosen and tighten normally except for the passenger front screw which when tightening it, it needs to be tightened an excessive number of turns compared to the other three screws, it does tighten up pretty snug (but not as snug as the other three). I am able to remove and replace the Targa Top but it concerns me that either the screw or the hole on the front passenger side is partially stripped. Not sure how to proceed.
All screws seem to loosen and tighten normally except for the passenger front screw which when tightening it, it needs to be tightened an excessive number of turns compared to the other three screws, it does tighten up pretty snug (but not as snug as the other three). I am able to remove and replace the Targa Top but it concerns me that either the screw or the hole on the front passenger side is partially stripped. Not sure how to proceed.
You can buy high quality used original GM parts on ebay for either the bolt or the mount in the roof frame...you just need to remove the bolt and take a look to see if the threads on the bolt are all stripped out.
if you've come to the conclusion that the bolt is stripped, and ONLY if...it might not be a bad idea to carefully try and run a tap up in the hole to remove any metal threads from the bolt that would have stripped off and is now fused in your threaded hole. you should be able to bring your bolt to a store like menards, lowes, home depot or even a good hardware store to check the thread size so you know which tap to get (metric threads have 3 pitch sizes 1.5 coarse , 1.25 fine and 1.0 extra fine) but again, this would only be done if your bolt is stripped...if your hole is stripped then you should look into buying a used mount off ebay and i would just go ahead and replace the bolts too...i'm sure you have damage on both components if you've been repeatedly performing this action...but this is such a non-issue...there are parts everywhere for a 91 roof so don't lose any sleep over this.
here's a picture of an extra bolt i have, this is an example of an almost perfect condition bolt as there is practically no sign of abnormal wear on the threads (disclaimer...i don't know if front and rear bolts are the same or different...i've never removed them) AND just something to think about, sometimes the roofs mounting hardware doesn't always line up with the brackets mounted to the windshield frame (especially if the roof was purchased later and NOT the original roof that came with the car)...it is possible that there is a slight alignment issue causing the drag which in that case would just cause the same condition to any hardware/bolt you replaced so a good place to start might be to see if the front screw goes in the mounting hole straight, do you have to tilt the bolt to get it to start or does it get pulled to one side as you're tightening it??
Last edited by mark970; 06-19-2017 at 09:36 AM.
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koritz123 (06-20-2017)
06-19-2017, 09:45 AM
#4
Drifting
i have a Youtube DIY channel for these C4's and i've seen a couple people with roof issues now...it's possible i could make a couple videos on the roof if there was interest. i have extra targa roofs so i could do a breakdown on them as well as a simple "how to remove and install the roof". As simple as that seems, if a person is new to Corvettes they could be doing it in a less effective way and possibly harm hardware, the car or even bodily harm as the solid fiberglass painted roof panels (28 pounds) are almost 25% heavier than a tinted glass panel (22 pounds for original GM and 24 pounds for a rebuilt with the new modern acrylic).
anyways here's a link to my channel if there is any interest
https://www.youtube.com/channel/UC49...4LdMJ_d2KjBznw
anyways here's a link to my channel if there is any interest
https://www.youtube.com/channel/UC49...4LdMJ_d2KjBznw
Last edited by mark970; 06-19-2017 at 10:35 AM.
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koritz123 (06-19-2017)
06-19-2017, 11:05 PM
#5
Racer
Thread Starter
i have a Youtube DIY channel for these C4's and i've seen a couple people with roof issues now...it's possible i could make a couple videos on the roof if there was interest. i have extra targa roofs so i could do a breakdown on them as well as a simple "how to remove and install the roof". As simple as that seems, if a person is new to Corvettes they could be doing it in a less effective way and possibly harm hardware, the car or even bodily harm as the solid fiberglass painted roof panels (28 pounds) are almost 25% heavier than a tinted glass panel (22 pounds for original GM and 24 pounds for a rebuilt with the new modern acrylic).
anyways here's a link to my channel if there is any interest
https://www.youtube.com/channel/UC49...4LdMJ_d2KjBznw
anyways here's a link to my channel if there is any interest
https://www.youtube.com/channel/UC49...4LdMJ_d2KjBznw
06-20-2017, 12:28 AM
#6
I have noticed in the past that if you snug up one side say Passenger side first the back Drivers side doesn't line up with the hole appearing as if stripped ! But if you only get a couple turns on all four started and then give a little love all around ? And at end just snug all four like a Spark plug especially if you have Acrylic Roof . DO NOT OVER TIGHTEN !
And while your first starting to thread move around a little kinda jiggle The Roof a little Gaurantee you will be good ! Have had same problem before ! Hope this helped
And while your first starting to thread move around a little kinda jiggle The Roof a little Gaurantee you will be good ! Have had same problem before ! Hope this helped
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koritz123 (06-20-2017)
06-20-2017, 12:42 AM
#7
Drifting
You might put something simple out there to new C4 owners on how to remove, store and put back on a Targa top by oneself. I did this the other night for the first time by myself in poor lighting trying to angle the top on the front and back rubber until I could get the back in place first. It worked but I could have dropped it. Also when I went to store it the latch pin toward the trunk was off center a bit. Not sure why.
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koritz123 (06-20-2017)
06-20-2017, 02:07 AM
#8
Racer
Thread Starter
the suggestion to swap bolts left to right will tell you if its the bolt or the hole...however the bolt should be pretty obvious if its stripped (but i suppose you would need to remove the bolt to see it)...its still a viable trouble shoot method and one worth performing.
You can buy high quality used original GM parts on ebay for either the bolt or the mount in the roof frame...you just need to remove the bolt and take a look to see if the threads on the bolt are all stripped out.
if you've come to the conclusion that the bolt is stripped, and ONLY if...it might not be a bad idea to carefully try and run a tap up in the hole to remove any metal threads from the bolt that would have stripped off and is now fused in your threaded hole. you should be able to bring your bolt to a store like menards, lowes, home depot or even a good hardware store to check the thread size so you know which tap to get (metric threads have 3 pitch sizes 1.5 coarse , 1.25 fine and 1.0 extra fine) but again, this would only be done if your bolt is stripped...if your hole is stripped then you should look into buying a used mount off ebay and i would just go ahead and replace the bolts too...i'm sure you have damage on both components if you've been repeatedly performing this action...but this is such a non-issue...there are parts everywhere for a 91 roof so don't lose any sleep over this.
here's a picture of an extra bolt i have, this is an example of an almost perfect condition bolt as there is practically no sign of abnormal wear on the threads (disclaimer...i don't know if front and rear bolts are the same or different...i've never removed them) AND just something to think about, sometimes the roofs mounting hardware doesn't always line up with the brackets mounted to the windshield frame (especially if the roof was purchased later and NOT the original roof that came with the car)...it is possible that there is a slight alignment issue causing the drag which in that case would just cause the same condition to any hardware/bolt you replaced so a good place to start might be to see if the front screw goes in the mounting hole straight, do you have to tilt the bolt to get it to start or does it get pulled to one side as you're tightening it??
You can buy high quality used original GM parts on ebay for either the bolt or the mount in the roof frame...you just need to remove the bolt and take a look to see if the threads on the bolt are all stripped out.
if you've come to the conclusion that the bolt is stripped, and ONLY if...it might not be a bad idea to carefully try and run a tap up in the hole to remove any metal threads from the bolt that would have stripped off and is now fused in your threaded hole. you should be able to bring your bolt to a store like menards, lowes, home depot or even a good hardware store to check the thread size so you know which tap to get (metric threads have 3 pitch sizes 1.5 coarse , 1.25 fine and 1.0 extra fine) but again, this would only be done if your bolt is stripped...if your hole is stripped then you should look into buying a used mount off ebay and i would just go ahead and replace the bolts too...i'm sure you have damage on both components if you've been repeatedly performing this action...but this is such a non-issue...there are parts everywhere for a 91 roof so don't lose any sleep over this.
here's a picture of an extra bolt i have, this is an example of an almost perfect condition bolt as there is practically no sign of abnormal wear on the threads (disclaimer...i don't know if front and rear bolts are the same or different...i've never removed them) AND just something to think about, sometimes the roofs mounting hardware doesn't always line up with the brackets mounted to the windshield frame (especially if the roof was purchased later and NOT the original roof that came with the car)...it is possible that there is a slight alignment issue causing the drag which in that case would just cause the same condition to any hardware/bolt you replaced so a good place to start might be to see if the front screw goes in the mounting hole straight, do you have to tilt the bolt to get it to start or does it get pulled to one side as you're tightening it??
06-20-2017, 02:26 AM
#9
Drifting
i dont know, i've never removed them. you may need to unscrew the plastic cover on the windshield frame and investigate. or at least try and get a visual of the screw with it still in the frame to see if the threads look good. you should be able to push the screw up and see the threads. if the threads look good (they will probably be shiny from all the rubbing) then i would just leave them in and investigate the bracket on the roof panel and look into replacing that. you can buy those parts on ebay.
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koritz123 (06-20-2017)
06-20-2017, 02:36 AM
#10
Drifting
this might be the easiest way to figure whats wrong here...the rear screws just come right out (keep unscrewing them until they come out) and then try it in the front roof mount thats giving you trouble. try this out of the car, on your carpeted floor or something and see if a different bolt goes in better or not. if it still feels really tight then i'd say your roof mount is bad and if the bolt goes in really nice, then i'd day its your front bolt. also, when the roof is in place...see if the bolt is aligned to the mount or if you need to tilt your wrench to get the bolt started. this test will let you know if the mounts on your roof are aligned with the mounts on your windshield frame. it is possible for them to not match perfectly if your roof isnt the original one for your car.
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koritz123 (06-20-2017)
06-20-2017, 02:41 AM
#11
Drifting
and really quick here are my tips for removal of the roof....
1) break all 4 bolts free, just break them dont loosen them much at all (to release the load on the bolts)
2) loosen the rear
3) loosen the front
4) check the front corners of the roof to make sure you have loosened the bolts enough by slightly lifting up on the roof
5) tilt the front of the roof up slightly and slide the roof forward
6) USE CAUTION as to not drop the roof, let it rest on the rear frame (B-pillar or "halo") if you need to re-grip
1) break all 4 bolts free, just break them dont loosen them much at all (to release the load on the bolts)
2) loosen the rear
3) loosen the front
4) check the front corners of the roof to make sure you have loosened the bolts enough by slightly lifting up on the roof
5) tilt the front of the roof up slightly and slide the roof forward
6) USE CAUTION as to not drop the roof, let it rest on the rear frame (B-pillar or "halo") if you need to re-grip
Last edited by mark970; 06-20-2017 at 02:56 AM.
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koritz123 (06-20-2017)