M1078A0/ Allison MD3070/ Drain Plug Threads

[Lugnuts]

Gentlemen: I said to myself, why reinvent the wheel?, Come to somebody who has already experienced this. I removed the drain plug on the Controller Box on the bottom of the transmission and drained the transfer box. I changed the filters and reinstalled the drain plugs to find out that I didn't have the threads to torque the plug into. Checked it with both plugs and it was the same. So I called Momma Allison and said surely you have a remedy for this and NO, Allison provides nothing for this. Got ahold of my favorite hydraulic shop and to was pointed out that if I put a helicoil in that the O-Ring surface will be damaged. Probably so. So here I am. Surely the Military had some of this happen? I am going to remove my piece of exhaust today and push come to shove I could probably rethread for pipe plug and use pipe dope to seal but first I want to check with y'all.
Thank you. PS. I do like my magnet in the drain plug so if I can save that it would be great.

 

[Keith Knight]

Probably not enough thread engagement for helicoil. Find a different drain plug with larger thread diameter and tap to match it. But insuring you get all the chips out is going to be the most difficult part.

 

[Lugnuts]

Probably not enough thread engagement for helicoil. Find a different drain plug with larger thread diameter and tap to match it. But insuring you get all the chips out is going to be the most difficult part.

Companies used to supply things as such for just these occasions. I think Japan still offers some. Thanks for the thought.

 

[GeneralDisorder]

+ TIME-SERT® STRIPPED OIL DRAIN PAN REPAIR KITS FOR STRIPPED THREADS + Stripped oil pan thread repair kits, leaking oil drain pan stripped or leaking threads stripped oil pan oil drain pan stripped threads stripped drain pan threads, leaking oil pan threads leaking, fix stripped oil drain pan leaking drain plug threads

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www.timesert.com

 

[Lugnuts]

+ TIME-SERT® STRIPPED OIL DRAIN PAN REPAIR KITS FOR STRIPPED THREADS + Stripped oil pan thread repair kits, leaking oil drain pan stripped or leaking threads stripped oil pan oil drain pan stripped threads stripped drain pan threads, leaking oil pan threads leaking, fix stripped oil drain pan leaking drain plug threads

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www.timesert.com

Thank you. I'll let you know what I do.

 

[Lugnuts]

So in further pursuing this issue I went to Allison and the parts department at Florida Detroit Diesel said that Allison has no resolve for this. I then got ahold of Weller Truck Parts, Grand Rapids, Michigan, pointed me in the direction of their remedy and that is Drain Plug 29510885 (7/8" x 14) which belongs to HT700 and tools Kent-Moore J-44344 or Snap On ATT 44344. Now General Disorder sent me a web site listed above and this is the way I am leaning at this point but I am still looking at a Helicoil with a touch of a countersink. Price is a factor to me. The other possibility is a 1/2" MPT with Pipe dope for leaks. The pipe plug could have a magnet JB Welded in to it.
By the way the original drain plug is 3/4" x 16 thread. I found this information a bit difficult to come by from dealer or internet.
I'll take feedback guys. Especially if you have had the experience of doing this. Thanks

 

[GeneralDisorder]

I've used the Timesert kits. Used one on an aluminum Ford transfer case a lot of years ago. Worked without issue.

The other option would be to get something like a Fumoto valve and epoxy it into the hole. Then you never actually have to remove it again. I use one of these for my engine oil drain.

T-204 - Engine Oil Drain Valve 3/4"-16 UNF | FUMOTO

These non-nipple valves can simply allow you to drain the oil. No hoses can be used, but their sizes are at minimum, and, compared to the regular drain plugs, they would only be added half inches in length from your oil pans.

www.fumotousa.com

They have an adapter for recessed holes. Not sure how it could help but I haven't looked at your situation in person either.

ADP-204: Adapter for T-204 Series (3/4-16 UNF) Valves

This adapter helps your Fumoto Valve fully seat on the oil pan when your vehicle has a recessed oil drain port.

www.fumotousa.com

 

[Lugnuts]

A report. I chose to go with a helical/ 3/4 x 16 repair/ I had plenty of room to drill, tap, and thread/ First one I put in I went to far and essentially didn't ike it. The second one I measure and cut the length for the hole, inserted and installed a thread deeper than the case. Installed plug and no leaks. The insert would probably worked out depending on how much needed to be drilled to house the insert. The earlier one that I was told about, the 7/8 plug I don't think that would have worked out because there is not all that much room between the bottom of the drain and the bottom of the case. It pretty much is on the very bottom. So if I ever were to do this again I would go with the helicoil and an oversize O-Ring for sealer. Thanks again for you suggestions