AOD trans pan questions

David Neibert

SCCoA Admin
I'm getting ready to install a new VB on the turbo car and expect about half the bolt holes for pan bolts to be stripped out, because the last time i removed the pan about half the threads came out with the bolt. I believe the bolts are 8 mm 1.25 pitch, but I can't remember how many there are....anybody know ?

While the pan is off I'm planning to repair all the stripped threads with helicoil but I'm unsure how the helicoils lock in place when the hole goes thru the flange as they do on some of the holes on the sides. I'm not concerned with the blind holes, just thru holes. I would like to use the keen serts, but they require drilling and tapping a much larger hole (something like 14mm), and I'm not sure there is enough material on the bolting flange to use them on all the holes. If anyone has repaired the pan bolt threads and can answer my questions, it would be apreciated.

David

PS: I'm also going to change over from Dextron/Mercon III to John Deere Hydraulic fluid.
 
Helicoils basically thread in to a hole you have drilled and tapped for them. After they installed you use a small screwdrive to break off the tip of them. I have never had them come back out on me when installed into a clean hole however if you are concerned use a little loctite on them. 8mmx1.25 is the correct size. Another tip if you are using a stock pan get one off of a 4x4 truck of full size bronco it will have a deeper sump. Make sure you get the matching filter for the applications all the stuff is still available from ford.
On the gasket I prefer the duraprene gaskets but I don't know an easy source to get them for everyone so just try to avoid cork.
Alan
 
Alan,

Thanks, I've got the duraprene gasket and the extended sump filter. The transmission came with a Lentech cast aluminum pan. Do you recall how many pan bolts there are, so I can be sure to buy enough helicoils ?

David
 
There should be 14 bolts. I am not familiar with the lentech pan, I know the mac one comes with some bolts that are too short they barely thread in I had to go buy 30mm length ones to use.
Alan
 
I have Lentech welded aluminum oil pan.I got & use longer bolts with it,
because the bolt flange was thicker. Don't remember the number
or bolts used.



Thanks Randy
 
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Dave, I stripped out 2 of the pan bolt threads on my TCI AOD when I dropped the pan the last time. I picked up a M8x1.25 helicoil kit from Advance for around $30. It came with about 20 coils, the installation tool, and tap. The only thing else needed is the proper drill size. Its been 2 years now and neither one of them has backed out or came loose.
 
CMac89 said:
David, you could just drill the holes out to the closest standard size and tap them.

Casey,

I thought about that, but with the amount of times I expect to be pulling the pan, I think the helicoils will be a better option. Besides that, this cast pan has thick sidewalls and doesn't have space to use a much larger bolt. I'm having to use socket head bolts with undersize OD washers now, because standard hex head pan bolts won't clear the sides of the pan.

David
 
For those of you not familiar with keen-serts, here is a picture:

inserts.jpg


The items shown at the 10 and 12 o'clock positions in the picture are keen-serts. This is what I used to fix a stripped hole on my transmission. However, I'm not sure if there is enough material to use these inserts on the sides of the trasmission pan mounting flange. Anyway, they may be overkill, but they definitely have more holding strength than a helicoil.

Completely off topic:

I found this while looking for pictures of keen-serts:

http://www.fulltorque.com/sparkpluginserts.htm

Looks like it might be a great way to repair stripped out sparkplug hole threads
 
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OK, a little more research reveals that the external threads on an 8 mm x 1.25 mm Keenserts is 12 mm x 1.25

For anyone that wants to do a little bit of reading, read this catalog. Enjoy.
 
Keen serts are the DADDY RABBIT of thread repairs......

We do a lot of repairs on cast iron and these are great for fixing wallowed or stripped bolt holes.....
 
Thanks for all the info guys....the new VB arrived today. Now I just need to get motivated enough to install it. Did I mention that I hate transmission fluid.

At this point I'm more interested in getting my 91 ready for the Shootout and golfing...so it may have to wait a while.

David
 
rzimmerl said:
Dave, I stripped out 2 of the pan bolt threads on my TCI AOD when I dropped the pan the last time. I picked up a M8x1.25 helicoil kit from Advance for around $30. It came with about 20 coils, the installation tool, and tap. The only thing else needed is the proper drill size. Its been 2 years now and neither one of them has backed out or came loose.

Do you know what size the drill bit is ?

David
 
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