Welcome to the Corvette Forums at the Corvette Action Center!

@#$*$ Broken Bolts!!!

milehigreg

Well-known member
Joined
Dec 3, 2004
Messages
271
Location
Denver Colorado
Corvette
1989 Dark Red Coupe
Decided to service the 700-R4 this Saturday. A relatively simple but messy job, right? Nope! Three of the sixteen bolts for the transmission pan sheared off. I was able to drill through all three but broke the extractor off flush with the top of the first bolt. Blue air. :mad Quit for the day. Got the next size larger extractor today and got it in each of the remaining bolts but was putting a lot of torque on them and was scared I was going to break the new extractor off as well. These babies aren't budging. The reason I am afraid of breaking off another extractor is that I can't drill thorugh the one that is already broken so I am hosed on that one. :cry On the other two I still have some options. Should I be more agressive with extractor? Should I just keep drilling them out and put in helicoils? How about just using self tapping screws? Anyone ever seen an external clamp? Any suggestion are appreciated. I am out of cuss words.
 
If they are stuck that tight, then someone crossthreaded them in the holes already. I retapped and helicoiled mine on the holes that hold the transmission linkage onto the pan edge. Thanks to my transmission rebuilder, they were crossthreded and stripped out. The Kit is about $35 for the Helicoil tap, inserting tool and 12 Helicoils. The part # is 5546-8 for M8x1.25" threads. Drill Dia. is 21/64" or .328"
I would go ahead and drill them out the rest of the way out to 21/64"
 
Get a lefthand drill bit that is very close to the size needed for tapping that size bolt. Often when you drill in reverse that close to the threads with a lefthad bit they come out with the bit. To drill out the extractor try a masonry bit on slow speed. Not sure it will work on the extractor but I know it works on hard steel such as leaf springs. Good luck.
:w
 
It's sealed

I got the pan back on and so far no leaks. I refuse to reveal how the pan is now attached. Let's just say that the next time it comes down will probably be for a rebuild and then we can go helicoil crazy!
 
milehigreg said:
I got the pan back on and so far no leaks. I refuse to reveal how the pan is now attached.

OK, I say it before 74 big block does.............DUCT TAPE? ;lol


lEN:W
 

Corvette Forums

Not a member of the Corvette Action Center?  Join now!  It's free!

Help support the Corvette Action Center!

Supporting Vendors

Dealers:

MacMulkin Chevrolet - The Second Largest Corvette Dealer in the Country!

Advertise with the Corvette Action Center!

Double Your Chances!

Our Partners

Back
Top Bottom