While replacing the transmission oil pan one of the 10mm bolts didn't snug up properly. Instead it just continued to "spin" in the hole. I removed the bolt and noticed the top half of the threads of the bolt had metal shavings on them. Then I looked up the hole with a flashlight and found what I expected . . . the hole was smooth instead of threaded.

I was thinking of simply retapping the hole with 1mm higher size and then using a bigger bolt just for this hole location.

Will this work?

Currently the pan is leaking at the gasket. I can't believe only one loose bolt would cause it to leak. I hope it is not more than that. I reused the same gasket but was hesitant as it was very stiff and there was only about an 1/8" amount of material around each bolt hole.

Is it also likely the gasket itself is worn out? If so is it ok to use the cheap one that comes with the filter or go to ford and get a proper reusable one?

 

Yes and yes. I believe this is what I would do. Use the cheap one.
Joe

 

I'd do it right and use a Heli-Coil. Not the cheapest way to do it, but the right way.

Pop

 

How do I figure out what size Heli-Coil to use? The bolt is 10mm (not sure of the thread count)

 

You mean 10mm head with a 6mm thread? If you go and ask for a 10mm bolt they'll come back with one about as big around as a cigarette. It's measured by thread diameter, not fastener diameter.
Personally I would just get a 7mm tap and bolt. A lot less metal is taken out of the casting that way and it will hold just fine.

 

another suggestion...does the bolt hole have any more threads deeper in the hole ? if so , run a "bottoming" tap in there to clean up the remaining threads and use a little longer cap screw...in some of the holes, they go all the way thru the case flange and you can put a nut on the backside. i would perfer to use the silicon reusable gasket, but it's your money. the pan bolts should be properly torque to prevent pulling the threads out and having leaks. hope this helps.

 

I'm a Heli-coil man myself. The biggest reason to use a heli-coil and the original bolt is if someone else works on your tranny, their going to put that over-sized bolt in a different hole and now you'll have two bad threads. The only thing to be careful about is that there's enough "meat" to do the heli-coil.

 

I have a busted bolt for the tranny pan it was that way when I bought it. Ihave changed the filter and fluid twice left the bolt alone no leaks.

 

heli-coil it. they are strong than the stock and really easy to do. also with the gasket get the new one from ford. the cheap one with the filter WILL leak even if you fix the bolt. i am a mechanic and have ran into this a number of times. any time someone uses the cheap gasket it leaks. i even converted my 95 over to the reuseable gasket whick required grainding the pan to make it fit and i am leak free.

 

If you decide to retap, you will probably have to go to an 8mm. Nominal pitch is 1.25mm on a bolt you would find at a hardware store, etc. A fine-thread 1mm & 0.75mm pitch is also available. 7mm is an exotic size & would be very hard to find. I don't see a problem with doing this because there's no way you will get this bolt started in a 6mm hole. Would cause a little inconvenience for the next guy though. (will require a 13mm wrench).

 

Unless there is something very wrong with the Tranny I will be the only one touching it (e.g. fluid/filter changes, etc.). At this point I am investigating retapping at 8mm (which is indeed way more common and easier to find a bolt)