Enersis

While replacing the Transmission gasket I noticed that I was missing a bolt(explained the leak). After removal of pan I found a broken off tap and die.

Well wasted 6 drill bits trying to drill out the tap, finally I drilled around the tap to get it out, Now i have a big hole.



I was thinking of filling the hole with JB wield, then drill and tap the JB wield, does anyone know if this will work or is there a better idea?

A88FXRS

how about a helicoil after you round out the hole ??

Enersis

I think its to big for the correct size.

JimT

Find a welding shop who can weld aluminum. I had a stripped out aluminum oil pan drain plug welded (filled), then redrilled and threaded. It can be done. Don't think JBweld would be strong enough - although I do use a lot of it myself!

SteveG75

Too big to helicoil right now and I would not trust JB Weld. See if you can get a welder to come over and put a quick bead in there. Easy job.

Chromie69

I have done both the heli coil and the jb weld on what you have..it depends on how big the hole is..if a heli coil is going to be used then I want the stock bolt size in there..if you can't use the stock size then fill it with the jb weld and then heli coil it..use the long cure stuff and not the quick..I have glued case corners together with that stuff..as long as it is very clean before you use it..it will stick..also do not clean out the hole with a drill..keep it ruff..

Enersis

Thank you.

PeteZO6

Here's another way to fix it. Drill the hole and tap it for a much larger size bolt. Using locktite to secure the bolt, screw it in and cut if off flush with the gasket surface.

Using the pan as a guide, drill and tap the center of the new larger bolt the correct size for a pan bolt.

Be sure your filler bolt is large enough to handle the pan bolt, and small enough to not weaken the case.


Pete

mds3013

Hey... this is a pretty neat idea. What about an aluminum bolt to thread into the case? If you use a steel bolt get a non graded one that is soft. mike...

forman

look up alumaloy ,, I used it on a trans ear and it worked fine you tube videos help

AZDoug

IF you can find an aluminum bolt. McMaster Carr may have some.

If you had lathe, you could thread up your own piece of aluminum.

My first though was drill and tap larger, install a threaded plug of some sort with JB weld,and then drill and tap correct size into the plug.


Doug

Enersis

Wow thank you so much guys, This is all very helpful

7t9l82

use a brass plug or bolt you can get them anywhere

mds3013

AzDoug is correct. You do not find them just everywhere. I remembered I had some in my stash so went to check. I have several 1/2-13 fairley hard aluminum bolts. I would be glad to send a couple to the OP if he is interested. I do not know if they are large enough or too large to fill that hole or if that is the best course of action. mike...

Gordonm

There is actually a piece tha tis already made for this application. Can't remember wha tit is called but our company uses these on the welders we make. It goes into a brass block and the threads are used quite often. The brass block threads were wearing out. We now use and oversize thread wit ha small inner thread. There is no head on it. It uses a slotted "head" so you put it in with a flat bladed screwdriver with some blue loctite. Let it set up and then thread in what ever you need. If it ever gets messed up again it is removeable. I have seen these on many machines that use an aluminum case and they don't want to use threads in the aluminum.

'75

This company makes thread inserts. The hole will be drilled and threaded to 7/16, then install the insert to make it the original 5/16 thread.

http://www.threadkits.com/keyinserts...erts_inch.html

Gordonm

As said above they are called thread inserts.

http://www.ezlok.com/InsertsMetal/index.html

Locke

I just used EZ Loc on the cast iron exhaust manifold were the alternator attaches to the front with great success.
Granger had them here in Jacksonville. Only problem is that I had to buy a pack of 5 to get the one I want and Granger is a little on the high side of the pricing matrix. It worked so well, I really didn't mind the price, alot less expensive than a replacement manifold.

One problem you might have is centering the threaded insert to the origional hole. Your current hole looks pretty out of round.

Locke

7T1vette

Redrill and thread the damaged area for a larger aluminum bolt (it can be mild aluminum...doesn't have to be aircraft grade--the tranny case isn't). Then, cut off the bolt to create a threaded plug. Ideally, the cut portion of that bolt shank should be made flat and square to the axis of the bolt. A backyard mechanic's way to do that would be to thread that "plug" into a hardened nut (same thread size), then use a belt sander to grind down that cut surface until it was flat with the hardened surface of the nut.

At this point, you can use some permanent Loctite to lock the plug in the 'new' threads on the tranny case, making sure that the surface of that plug is flush (as possible) with the gasket surface. You can use a stone to get it to be 'true' with that surface, if you wish...but the new gasket should allow it to seal fine.

Once that sets up, you can loosely install the tranny pan with about 4 or 5 bolts inserted by hand. Use a center punch to indent the location for drilling for the pan bolt. Remove pan, drill & tap hole, and it should be ready to reassemble.

Note: Repair shops usually drill a small hole at one spot on the threads of that aluminum plug, then install a press-fit piece of drill rod to prevent that plug from ever rotating loose. Instead of using Loctite on the threads, I suppose you could install such an anti-rotation pin; or you could use some epoxy to glue it into those threads when you install the plug.

If you choose to use this kind of approach, I hope it works well for you. Just be careful not to drill too far thru that pan rail when you drill for the plug and drill for the new bolt. You can do really bad damage to the main case if not careful.

P.S. For future reference: (I know this is of no help to you now, but others may benefit) There are little kits made to use for removing broken tap pieces. It is called a "tap extractor" and the brand I'm familiar with is Walton in West Hartford, CT. I'm sure you can Google it to find out how they work.

dugcyn

+ a million to keensert. it is designed specifically for this. it is also a bullet proof fix.
you will however need a machinist to bore the hole in the correct location as your current hole does not look like it will pilot on center. an option to this would be build a drill jig with bushing to guide location.
drill and tap very very carefully, you dont want to know what the next step and cost to fix it is if you break something else in the hole.

Doug