Stripped threads in top mechanism!!!
Thread Starter
On The Tree
Joined: Dec 2004
Posts: 189
Likes: 1
From: Austin, TX
Stripped threads in top mechanism!!! Here's the first fairly major problem I've had with my 98 Z28 ragtop since I bought it last year with 107K on it. I have 121K now. Figured I'd post since our cars always share the same problems... Might be something to check out on yours.
I was putting my top up last week and when it was about 2/3 closed I hear a nice "clunk!-clank!-clank-ting-clunk" sound from the passenger side, and the top hit my pass window as it closed. It closed OK with some help, but this did not look good.
What I found was a shoulder bolt had fallen out of the linkage (see pics), and down into the abyss of the rocker panel. I fished around with my magnet-on-a-stick for a few minutes, but it didn't come up so I ordered a new one.
When the new one came in, it was very easy to put everything back together, but then when the bolt should've bottomed out & gotten tight, of course it didn't...
Yep, stripped. On closer inspection of the new bolt, it looks to have some type of self-locking geometry - it's sort of triangular on the end. The threaded hole is in cast aluminum, which is not the greatest material for threading to begin with, and combined with deformed-thread locking design, it's a wonder it held up this long.
The fix was actually pretty easy - I figured out the thread size, which is M8x1.25, and went to the local *good* auto parts house and bought a Heli-Coil kit. I stuck my shop-vac up under the hole as I was doing the drilling and tapping to catch the chips before they went into the abyss. Took all of 20 min including getting tools out & putting them away, and the end result should be stronger & more durable than the original design by quite a bit. It is now stainless on the 8 mm self locking threads, and the aluminum threads are just normal round threads, and on a larger diameter - more like 7/16".
I checked the same bolt on the other side, and it seemed fine, but due to the nature of the self-locking design, I probably shortened its life a bit just by messing with it. I also used Loctite blue on both sides when I reinstalled.
If you want to check yours, I recommend just putting a Torx socket on it and seeing if you can tighten it a bit. If it just spins with medium resistance, you have this problem too. Good luck & post anything you find!
Trace
I was putting my top up last week and when it was about 2/3 closed I hear a nice "clunk!-clank!-clank-ting-clunk" sound from the passenger side, and the top hit my pass window as it closed. It closed OK with some help, but this did not look good.
What I found was a shoulder bolt had fallen out of the linkage (see pics), and down into the abyss of the rocker panel. I fished around with my magnet-on-a-stick for a few minutes, but it didn't come up so I ordered a new one.
When the new one came in, it was very easy to put everything back together, but then when the bolt should've bottomed out & gotten tight, of course it didn't...
Yep, stripped. On closer inspection of the new bolt, it looks to have some type of self-locking geometry - it's sort of triangular on the end. The threaded hole is in cast aluminum, which is not the greatest material for threading to begin with, and combined with deformed-thread locking design, it's a wonder it held up this long. The fix was actually pretty easy - I figured out the thread size, which is M8x1.25, and went to the local *good* auto parts house and bought a Heli-Coil kit. I stuck my shop-vac up under the hole as I was doing the drilling and tapping to catch the chips before they went into the abyss. Took all of 20 min including getting tools out & putting them away, and the end result should be stronger & more durable than the original design by quite a bit. It is now stainless on the 8 mm self locking threads, and the aluminum threads are just normal round threads, and on a larger diameter - more like 7/16".
I checked the same bolt on the other side, and it seemed fine, but due to the nature of the self-locking design, I probably shortened its life a bit just by messing with it. I also used Loctite blue on both sides when I reinstalled.
If you want to check yours, I recommend just putting a Torx socket on it and seeing if you can tighten it a bit. If it just spins with medium resistance, you have this problem too. Good luck & post anything you find!
Trace
