Corvette GS786

Hello,

I was wondering if anyone could provide me with some assistance. Last oil change they commented that a might need a new drain bolt for the next change (which is on Friday). I was looking on-line for a replacement, but there appears to be two listed for 1996. A early and later edition. Are they just the same bolts with different heads (Metric vs Standard) or do I need to know exactly which one my car takes. If I do need a certain one, how would I find that information out? I have a 1996 Grand Sport.

Thank you for any assistance!!

Whaleman

https://www.ebay.com/itm/Engine-Oil-...RbHiII&vxp=mtr
I THINK this is what I bought for my 96 LT1. Old one was giving some drips. It fit perfect. Dan

RetroGuy

If you did the oil change yourself, you could remove the old drain bolt and go to an auto parts store nearby to get another that matches it perfectly. My LT1 plug was 1/2 inch. However, I discovered there were different thread counts available on new bolts (number of threads / distance between threads) that the parts store sold so it was great to physically match the old with the new one to be sure.

Whaleman

I agree. This is the best way. Dan

WVZR-1

It's either 1/2-20 OR M12X1.75 - You might only require a new gasket/seal for whichever is there. I doubt you could rely on the 'comment'.They're different. Nearly everyone I've ever talked to says theirs was 1/2-20 and maybe it's only SPO Service Pans that were offered in the Metric Spec.

Is the same shop doing it again?

aklim

Why? Is the head rounded off? IF so, why? Because He Man over torqued it and it stuck in the pan? Are you sure the pan is not stripped? I think it is more likely the pan is stripped than the bolt threads. If the head is stripped, get a new bolt by bringing it to the Fastenal or Grainger shop for a comparison.

Corvette GS786

Thanks everyone for the responses. They informed me last oil change that it looked like there was something wrong with the bolt. In scheduling this oil change I wanted to pick-up a new bolt. Easier said then done with the fact that two different ones were listed for 1996. The problem is that I know the bolt on the car isn't original because it has a magnet, so I wonder if the wrong bolt was put it. So I want to make sure that I get the right bolt and don't appear to have the original to look at. I called the dealership today and they looked it up via VIN code and it show the M12x1.75 bolt. I bet that is the case. Thoughts?

aklim

What EXACTLY is wrong? Are the threads stripped? Is the nut head rounded off? Is it the wrong size? Is it the gasket leaking?

WVZR-1

I wouldn't rely upon that 'except that' the M12X1.75 OE/GM - would have had a magnet I believe and use a different sealing system than the 1/2-20. Buy both and carry with you.

GM # 24100042 would be the Metric with seal & magnet. Should be images everywhere for you to check out. If the shop told you it looked to be needed then maybe they were actually 'knowledgeable' and knew the seal was serviced with the plug.

The GM current replacement may no longer be serviced with the magnet.