C4 Tech/Performance L98 Corvette and LT1 Corvette Technical Info, Internal Engine, External Engine

Driveline bolts

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Old Sep 18, 2023 | 06:09 PM
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Default Driveline bolts

Had a devil of a time getting the transmission out
Used a 1,200 ft-lb rated impact to get the transmission to bellhousing bolts out
It was anti-seized, but they're going into magnesium.

I'm just going to replace what I can find.
The rest of the driveline bolts I found in available kits
The only source I found for the M12x45's holding the trans to the bellhousing is McMaster-Carr

Just curious where people got theirs.

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Old Sep 18, 2023 | 06:38 PM
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Originally Posted by BrianCunningham
Had a devil of a time getting the transmission out
Used a 1,200 ft-lb rated impact to get the transmission to bellhousing bolts out
It was anti-seized, but they're going into magnesium.

I'm just going to replace what I can find.
The rest of the driveline bolts I found in available kits
The only source I found for the M12x45's holding the trans to the bellhousing is McMaster-Carr

Just curious where people got theirs.
Are they flange headed? The OE I see for '91 + L98, LT1/4 spec'd for 45 length but '89 and '90 + all LT5 are spec'd at 40 length. I've messaged a friend to see if GM might offer a replacing equivalent but I won't hear from him until tomorrow late in the day.
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Old Sep 18, 2023 | 08:15 PM
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yes, flange head, but I'm not finding any in the length that are fully threaded.

Figured I'd be running washers, but I need to make sure they'll clear.

They're NOT through holes, so you need to get the length right.
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Old Sep 18, 2023 | 09:06 PM
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I find 10.9 Flanged Head 40mm that's likely thread to head and a 45mm that's likely NOT but both are 'Flanged Head'. Let's see what my friend tells me tomorrow. I find many 40mm full thread 10.9 bolts.

**** Is there an Isuzu Truck dealer near you?
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Old Sep 19, 2023 | 11:21 AM
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Originally Posted by WVZR-1
**** Is there an Isuzu Truck dealer near you?
Would they have the bolts?
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Old Sep 19, 2023 | 11:51 AM
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Originally Posted by BrianCunningham
Would they have the bolts?
That would be a reasonable starting point if I were shopping them. A truck dealer of any brand so long as you can carry in a sample. A local spring, frame or heavy duty shop also. You got I see my PMs!
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